Introduction into Speciality Diving – Getting personal with our students experiences
Have you ever wanted to stay down a little longer and a little deeper and reaching the limits of recreational diving but not sure what avenue to take in order to do that? Well during this blog we have a detailed overview of what you could expect from speciality diving with Big Blue Tech.
To begin we have an introduction into speciality diving, then move on to a Q & A session with our current Tech Manager Andy Campbell, who isn’t just the brains and beauty of Big Blue but the instructor that is likely to run your speciality course with one of the team; finally reviews from previous and current students who are exploring a world with endless possibilities.
Speciality diving? Well what is it? These are the courses that hone your skills and make you a better diver, they allow you to expand your knowledge / confidence / diving ability and safety… oh and can extend your dive times as well as allowing you to penetrate ship wrecks (there are still limits!) and dive in new configurations such as sidemount
That’s just the start of speciality diving, there is a world of possibilities that are open to all levels of divers who maybe once didn’t think they were capable of or maybe didn’t know existed. In Koh Tao we are very fortunate to have an abundance of dive sites and marine life our boats fin tips, as well as Big Blue Tech being able to provide certifications through SSI / TDI / SDI & PADI all of which will be covered in a little more detail in the Q&A section of this blog.
The reason we can expand our diving capabilities these days is down to the US Navy and some very intelligent men who realised what gases were needed at what depth and what could be so cool about diving with two tanks… well let’s hope we can answer all of your strange and wonderful questions about speciality diving, with the hope that you will understand that doing tech isn’t as scary or intimidating as people make out we only want to make ‘knowledgeable, confident and safer divers’. All the questions and feedback are from real students past and present that had the same questions as maybe you have about speciality diving and what it in tales.
Q&A – With Andy Campbell on an Introduction to Speciality Diving
- What are Specialties?
“The specialties or “Specs” are courses divers can take in order to further their education, they typically last 2-3 days as we add more dives than are requested by the agencies.
In general divers who have completed the advanced course are interested in pushing on to 40m or diving on Nitrox but Navigation and Buoyancy are also skills people want to take to the next level and of course the wreck course is also very popular”
- Are there any requirements for someone to start one of the specialty courses?
“Enthusiasm! As long as you have an open water certification and want to get better then we can look at many options, of course a few fun dives is never a bad thing and we’re lucky here to have great Divemasters that demonstrate just what good buoyancy is whilst leading and it’s not un-common for divers to come in and sya they want to be able to dive lie a Divemaster”
“If you wish to progress past recreational diving and into the Tech side of things then there are prerequisites and in general divers wishing to take these courses have a reasonable amount of experience”
During a course’s such as Nitrox, Deep or Sidemount what is typically required ? And what skill does it in tale?
“All three are great courses and allow you to take on more challenging diving but fundamentally they all involve an academic session Sidemount is a course where you learn to wear one or two tanks on your side instead of on your back, but all of the courses have additional focus on the bedrock of good diving – Buoyancy”
“Nitrox, used to be considered as the first step towards tech as it could extend bottom times and gives the diver a choice of breathing gases for the first time. Nitrox in itself is nitrogen and oxygen and students are trained to use between 22% and 40%, the benefits are huge but it comes with a risk on the oxygen side so divers need to be able to analyse tanks and calculate maximum operating depths, not as ominus as it sounds and actually my first spec”
- Some people find the idea of specialties daunting, why do you think this is?
“It’s natural but hopefully they’re excited at the same time, continued dive education should be challenging but rewarding at the same time and after all a majority of our customers are on vacation so it should be fun as well. After the training I’m a great believer that the customer should dive the “spec” without their instructor in order to experience it and to provoke further questions so we also have Divemasters available to dive in any configuration and on Nitrox… it’s time to reap the rewards for sure”
“We try and make the academics as straight forward as possible and to keep elope within their comfort zone, this isn’t rocket science I can assure you or I wouldn’t be teaching it! But it does need to be understood and certainly plays a large part in diver safety”
- Why should someone be interested in exploring specialties and technical diving?
“Well I guess like any other hobby and for most people diving is a hobby each time you go diving you either want to become a better diver or see something different or just chill out. Specialties allow you to extend from the basic courses of open water and advanced adventure towards the limits of recreational diving, so deep diving allows you down to 40 meters; Nitrox which will allow you to stay longer at a given depth and wreck where we can teach you limited wreck penetration”
“But in order to go beyond recreational limits by going deeper and staying longer then technical diving is the extension from recreational diving that will allow you to do so”.
- What are the benefits to moving from recreational diving to technical recreational diving?
“I would like to think that you’re not moving from one to the other, I still go out and recreational dive, still have fun diving on a single tank. However if the dives I want to do entail going beyond the recreational limits then it’s into technical diving”
“Of course the obvious benefits of Tech are extra depth and time but it’s based on additional knowledge and skill sets some of which are challenging but very rewarding. The dive day changes as does the approach to planning and executing dives but the fundamental reason we do it does not change… it’s a great way to spend time!”.
“So for me it’s like having the right tools in the toolbox do to the dives that you’re interested in and that also requires keeping skills competent and up to date. Refreshers and pool training no matter where you are is a valuable part of preparation for that vacation”
7.What are the costs of the courses?
“Like anything else they can vary and some are more expensive because there are more dives involved and the courses are longer or more equipment is required, so the more intense the course the more it’s going to cost but the more you are going to get from it as well”
“The basic courses at Big Blue Tech specialities start from 5,500 baht; and increase to 8,000 Baht. However you have to look at what you are going to get from it and certainly here with Big Blue Tech we try to maximize this and can tailor packages to suit everyone.
- Most people are not technically focused i.e. mathematical or scientific.. baring this in mind how is the theory side of the courses, and how can that be focused around people who maybe need a little more time understand the theoretical and technical side of the course.
“The internet is a wonderful thing. We now have the majority of our courses available through SSI, TDI and SDI with e-learning so you can do the academics before you arrive and work with your instructor online. You can approach Big Blue Tech and we can sign you up and we can get the online training done before you arrive this gives people time to understand it rather than trying to do it over a limited period of time, when after all they’re on vacation”
“So my advice would be if you want to find out more about the theory of specialty and technical diving then get in touch with a technical diving instructor, I personally spend quite a lot of my time answering questions online from email inquiries and fully encourage anyone to explore this avenue”.
- What is the greatest benefit you can get from just doing one speciality course?
“Experience! But you will only get experience if you take your speciality course and dive it, you could do a buoyancy speciality for instance and then if you don’t dive again for a year you will probably remember some of it but not all of it. So it’s about doing it at the beginning of the vacation and then getting your fun dives in and practicing the skills you learned”
- What’s the difference between TDI, SDI, SSI & PADI in relation to speciality and technical courses?
“Okay so, SDI and TDI which we offer at Big Blue Tech are part of the same family. TDI is technical divers international and SDI is scuba divers international. SSI is scuba schools international and they offer specialities in both recreational and Tech under the TXR an EX brand, whilst PADI also offer specialties and Tech with Tech falling under TecRec”.
“Customers can choose to mix and match with all certs recognised worldwide, so no issues there”.
- What is the philosophy behind technical diving at Big Blue Tech?
“Safety has to be the foundation underpinning all the courses and training we offer, after that the creating sharing knowledge and making sure our students use this, one quote shown to me during my training has stuck with me and I mention it at the start of all my courses”
“The key piece of equipment is a knowledgeable and thinking diver”
“all of the training we conduct is based around this and we encourage continued discussion on completion, I don’t believe our duty of care ends on certification and if a past student seeks clarification then it is always welcome, if in the future they feel they can add something then that’s also part of my own education”.
- Do I need to supply my own set of equipment?
“Nope, we can supply all of the equipment you need at Big Blue Tech. However by the time you get to the level where you want to do tech courses we do expect you to have some basic equipment and there is a small additional rental fee for some basic equipment”.
- What is the best piece of advice you can give someone looking into specialty or Technical diving courses diving
“Look around and challenge the people that you want to train with, if they don’t have time to answer your questions now then maybe they won’t once you arrive. It’s not all about the price like everything else in life, you can get good value for money…but would you buy a cheap parachute?”
- What are the general course durations?
“Anything from one day, to multiple days or even weeks for some packages depending on the speciality and time frame you are working with”
- Are wrecks scary to penetrate?
“The word scary no, I would say it’s more exhilarating”
“If you have got to the point where you want to penetrate a wreck, then I can almost guarantee your first dive will be amazing, when you go into the overhead environment for the first time, everything comes alive! You know your somewhere you want to be”.
“That’s why you do the training,the big thing about doing this type of speciality is the preparation and the understanding of the environment you are going into whether its wreck or cave”
- Do you need specific technical courses in order to do other tech courses i.e. do you need to do your nitrox in order to do your advanced nitrox?
“Yes there are pre-requisites and they are laid out by each of the agencies. They are fairy similar although not all tech certifications from different agencies are equal but you will find any technical instructor that you talk to or will talk you through the pre-requisites. But yes if you want to become an advance nitrox diver you need to be a recreational speciality nitrox diver”
- What course spec bundles is big blue tech currently running?
“We are very fortunate at Big Blue Tech that we have our own boat, but also we have several instructors teaching the bundles. So normally we are in a position to bundle a package to cater for someone’s needs.
If someone comes in and doesn’t want to go deep but wants to go nitrox and penetrate the wreck we can teach that bundle”
“If someone comes in and go all the way through to advance nitrox and deco procedures then we can do a bundle to fit the time scale that they have. But they should have a reasonable amount of time because again in between different courses we want them to do some fun dives in before they move to the next level”
Hear from the students themselves, what they did and how they found doing speciality courses
TOM – DMT
Course – Wreck & Nitrox
Tom said the reason that he wanted to get his specs for nitrox is that he would want to expand his knowledge and extend his dive times when doing his next speciality which was the wreck course. During the course: Andy’s teaching was outstanding, he was direct, through funny and really got you involved. What stood out the most with my course is that Andy really helped me understand in detail things I didn’t understand before about the theory and practical of these speciality courses.
Tech career continued – Tom will further his career with tech specialities by going on to deco and advance nitrox – as he wants extended range on his dives and get a deeper knowledge of the subjects in order to make him a better diver during his career.
Andy’s funniest moment with his student: “Tomathy as he is known in the tech shack… great student lots of interesting questions. Worked really well with Mike both have now slowed down and learned how to ‘not’ penetrate prematurely and enjoy the moment… wreck diving have become a passion for them”
NATHAN – DIVEMASTER
Course – Nitrox, Deep & Sidemount
Nathan was introduced into tech by seeing a couple of Big Blues instructors doing sidemount and the way in which they were diving they seemed to be kicking their fins and gliding with very minimal effort which sparked his interest into how they were able to do it, and if he would be capable of becoming that skilled and become a safer diver. Nathans thoughts on the courses were that Andy was very detailed in his teaching and pedantic. He makes you think that you are your own worst critic and only you can be the best you can which encourages you to be the best you can be.
Signs / signals and instructions in and out of the water were very clear and understandable. If you had issues under the water with a skill or somewhat it is dealt with then and there, you do not dwell on it when you get back on the boat you only look at ways to improve yourself for your next dive. Ideally when you have someone who you dive with who is just as passionate about diving and side mount and enthusiastic to learn and develop their knowledge and skills as you are it makes the experience so much more enjoyable. One of the best moments I’ve had was being able to have a 124 minuet dive at Sail Rock (one of Thailand’s best dive sites) diving sidemount with nitrox, without the skills and certifications I would never be able to have that experience
Nathan has completed a 124 minute dive at Big Blue – In his top 5 best life experiences
Tech career continued: Nathan would follow through with every tech course possible trying to add a new one each time he visits Thailand and Big Blue his quote “keep learning, keep diving keep practicing your skills”
Andy’s funniest moment with his student: “Nathan what an amazing diver – with one of the best buddies ever with Angelika. Will always be remembered for the ‘Nathan check’ please ask him about this”.
“Memorable moment was the 124 minuet dive at sail rock with Tim – a true gentleman”
AMYE – DIVEMASTER
Courses – Deep, Nitrox and Sidemount
Over the past few months I took several courses, I began with nitrox, continued with my deep certification and became hooked on the more technical side of diving. Learning to dive sidemount was always a goal for my diving career. At first I felt overwhelmed with the transition
From recreational with one tank to a completely new style, technique, and equipment that was entirely foreign to me.
Andy was a phenomenal instructor, not only does he teach but he pushes you to be your absolute best, no excuses. The more you dive with him gives you more of a reason to continue with your certifications because he becomes both your instructor and also a mentor. At first tech diving seemed to be entirely too intimidating, but it has made me a far better divemaster and diver. You understand the science of diving more thoroughly and you fall more in love with it as you can begin pushing the limits of both yourself and the possibilities.
Tech career continued: Amye continue in tech with a wreck certification and explore advanced nitrox and deco diving.
Andy’s funniest moment with his student: So many funny moments and such growth in someone’s diving ability. She has plenty of character & has an awesome mother who has just done her open water. 40 meters deep dive in zero viability and sitting in a ball of fish who knew not where they were.
Big news- Big Blue Tech is under new management! Richard Devanney (left) and Donny McFadden (the other one) have taken over from outgoing manager James Foleher and his glamorous assistant Ian. James has decided to pursue other ventures, and Ian will be continue to teach recreational diving with Big Blue.
So from the 25th May, Rick & Donny will be in charge of the technical diving department at Big Blue. They have both been at Big Blue for years, and have a lot of experience to bring to the role. They are very passionate about their diving, especially technical diving, and believe in trying to make every student they teach become the best diver that they possibly can. They are not the type of people to cut corners either; every course they teach is to a very high standard, putting the safety of the student first every time.
Prior to being involved in the diving industry, they both had very varied careers. Rick has worked as a metallurgist, melting steel in steel foundries (i.e. getting burnt for a living), a geologist on oil rigs all around the world, and before he came to Koh Tao was involved in sustainable energy for 7 years. Donny worked in the commercial construction industry for many years in Australia, and has for a long time been heavily involved in the music business as the lead singer/bassist of punk rock band Lamexcuse.
They are passionate and enthusiastic about their new role, and are currently busy developing a number of ideas with which to take Big Blue Tech forward. Big Blue Tech would like to thank James and Ian for the work they have done over the last few years, and wish them well in their future endeavours.
Big Blue Tech has a pretty broad online presence, so whichever medium you use, you can like Big Blue Tech on facebook, follow us on twitter as @BBTechThailand. We’re even on Instagram as.. you guessed it, Big Blue Tech. If you’re feeling old fashioned then just have a look at the Big Blue Tech website (you’re on it now!). They will all be regularly updated with information on technical diving, training, expeditions and Big Blue Tech events. Also, if you live on Koh Tao join the Big Blue Dive Club on facebook. It’s a group open to any dive professional and DMT on Koh Tao, aiming to provide information on the regular dive trips that Big Blue Tech will be running, open to all on a first come-first served basis. But seeing as Koh Tao is pretty small, you can also just pop in to the tech shack for a chat too!
With big things in store for us here at Big Blue Tech, we’re excited for the future and invite you to come diving with us!
Patent Foramen Ovale and Decompression Sickness
Douglas Ebersole, MD
Patent foramen ovale (PFO) is a very popular topic in scuba diving as the appreciation of its relationship to decompression sickness (DCS) becomes more widespread in the diving community. Though the incidence of DCS in recreational diving is only about 2 episodes per 10,000 dives, decompression sickness affects approximately 1000 divers per year. The presence of a PFO is felt to increase the risk 5- to 13-fold (1-3). An understanding of the link between PFO and DCS as well as various treatment options is vitally important to health professionals who treat these patients.
Incidence and Anatomy
The patent foramen ovale is an integral part of the normal fetal circulation. Normally, a portion of the blood from the inferior vena cava passes from the right atrium to the left atrium through the PFO during fetal life, bypassing the lungs. At birth, pulmonary blood flow increases greatly, increasing left atrial pressure. The resulting atrial pressure differences compress the septum primum against the septum secundum, functionally closing the PFO. Anatomic closure of the PFO occurs later in infancy in most people but is incomplete in approximately 25% of the population (4,5), leaving these individuals at risk for right to left shunting. PFO diameters are quite variable in size ranging from 1-19 mm with the average size being larger in older adults (4), suggesting PFOs my continue to enlarge during life.
Relationship of PFO to DCS
It was first suggested in 1986 that a cardiac right to left shunt may be important for paradoxical gasembolism in scuba divers (6). Subsequently, the importance of PFO for DCS in divers has been further investigated (1,7-10). As mentioned above, the risk of DCS in sport divers is quite low but is increased by at least 5-fold in the presence of a PFO (1-3). Additionally, the average number of ischemic brain lesions as seen on MRI in experienced divers with PFO has been reported to be twice as high as in divers without PFO (11). The etiology and clinical significance of these findings are unclear but may represent multiple subclinical paradoxic embolic events across the PFO.
Both transthoracic echo (TTE) and transesophageal echo (TEE) have been used for the diagnosis and assessment of PFO. TEE is the preferred diagnostic test of choice, however, given its better visualization of the atrial septum resulting in greater sensitivity in making the diagnosis.
The injection of agitated saline increases the diagnostic sensitivity by enhancing echocardiographic detection of the trivial intermittent right-to-left shunting across a typical PFO. Agitated saline contrast injected intravenously during Valsalva maneuver with release of straining when contrast is visualized in the right atrium increases sensitivity. Visualization of contrast microbubbles passing from the right to left atrium through the visualized foramen ovale during the release phase is diagnostic of an interatrial communication. In clinical practice, the actual site of right-to-left shunting may not be convincingly visualized or recorded for technical reasons. If a recording co
nvincingly demonstrates microbubbles appearing in the left atrium immediately after arriving in the right atrium, then the presence of a PFO can be presumed. If bubbles appear in the left atrium before or > 5 beats after they appear in the right atrium, then the possibility of anomalous pulmonary arteriovenous connection to the left atrium or pulmonary arteriovenous malformations must be considered.
Contrast injected through an upper extremity vein may be washed away by contrast-free blood flow from the inferior vena cava directed by the Eustachian valve, creating a false-negative result (12). Injection of contrast via the femoral vein has been proposed to enhance detection by TEE, with the streaming effect of directed inferior vena cava flow to the region of the fossa ovalis and through a patent foramen (13).
No specific guidelines exist for PFO closure in people who have decompression illness, but the options are to stop scuba diving, decrease the depth and/or time of dives to limit the inert gas load, or undergo percutaneous PFO closure. Some divers decide that they have many other interests and diving is not that important to them. These divers will frequently give up the sport. Other divers who enjoy the sport but dive infrequently often opt for diving “conservatively” to limit their bubble-load. This would involve no-decompression diving, limiting depths to < 100 feet, diving nitrox on air profiles, prolonged (> than the usually recommended 3-5 min) safety stops at approximately 15-20 feet at the end of their dives, and limiting the number of dives per day to one or two. People who make their living through scuba diving (instructors, divemasters, etc) and divers who enjoy more aggressive types of diving such as deep wrecks, cave diving, rebreather diving, and mixed gas diving often elect percutaneous closure of the PFO. This also holds true for divers who have had recurrent “unexpected” DCS events despite diving conservatively as defined above.
A recent study reported the results of conservative diving practices after an episode of DCS (14). Eighteen divers in this study had a right-to-left shunt, nine were small and nine were large. Mean follow-up was 5.3 years (range 0-11 years). Four of these divers had undergone PFO closure and had no episodes of DCS in follow-up. The absolute risk of suffering DCS before examination for the remaining 14 divers with right-to-left shunt and no closure was 23.5 DCS events per 10,000 dives for those with a small shunt compared to 71.6 for those with a large shunt. After recommendation for conservative diving practices, the DCS risk at follow-up fell to 6.0 per 10,000 dives in the small shunt group and zero in divers with the large shunt. The major limitation to this study is its small sample size, but the results suggest a need for more studies of conservative diving practices for divers with right to left shunts.
When DCS has occurred, especially after so called “undeserved” cases of DCS, divers are often encouraged to seek screening for a shunt and some diving medical societies classify these divers as ineligible to return to diving (15). There are also several diving medical specialists who recommend divers with a history of DCS and a positive right-to-left shunt to undergo closure if it turns out to be a PFO, even though there is no clear evidence to indicate that this intervention reduces the risk of DCS or neurologic events (16-19).
However, in a 2011 study of 83 scuba divers with a history of DCS and a follow-up of 5.3 years, 28 divers had no PFO, 25 had a PFO closure, and 30 continued diving with a PFO without closure (20). At the beginning of the study, there were no significant differences between the groups in the number of dives, dive profiles, diving depth, or cumulative dives to more than 40 meters of salt water (msw). After follow-up, while there were no differences between the groups with respect to minor DCS events, the risk for major DCS was significantly higher in the divers with PFO and no closure than in divers with PFO and closure or divers without PFO. Although this offers new evidence that PFO closure reduces the risk for major DCS, the authors do not recommend closure in all divers with a history of DCS but rather recommend further studies to confirm these results.
Percutaneous PFO Closure
The closure procedure for a patent foramen ovale is relatively painless and is done percutaneously through a femoral vein. Imaging during the procedure is done with a combination of fluoroscopy and ultrasound imaging, either TEE or intracardiac echo. The most common device in use in the United States is the Amplatzer Cribriform Occluder . This is a wire mesh made out of nickel and a titanium alloy. The device is filled with securely sewn polyester fabric to help close the defect. It is deployed through a small catheter which has been placed across the PFO. The procedure takes about an hour and patients are usually discharged home the same day or the following morning.
In 2010, Divers Alert Network (DAN) began a five year prospective non-randomized study following divers with a history of decompression sickness and a PFO, whether or not the diver had chosen to have the PFOclosed. At this time there are 60 of the planned 120 participants enrolled. Divers interested in participation can find more information at http://www.diversalertnetwork.org/research/studies/risk_benefit_of_pfo_closure.
Conclusions and Recommendations
- Should all divers be screened for a PFO? No. There is approximately a 5-fold increased relative-risk of DCS in patients with PFO, but the absolute risk is still quite small.
- Should all divers with DCS be screened for a PFO? No. Twenty five percent of the population has a PFO so one would expect a similar percentage of divers with DCS to have a PFO. Not all scuba dives have the same risk of DCS. To paraphrase James Carville’s famous quote from the first Clinton presidential campaign, “it’s the bubble, stupid”. The issue with decompression sickness is the inert gas “bubble load”, not the PFO. However, episodes of DCS in “low-risk” dives, especially neurologic events, or multiple “undeserved” DCS events should prompt investigation for PFO.
- Should all divers with DCS and PFO have a PFO closure? No. Options for divers with PFO and DCS include discontinuing diving, conservative diving practices, or PFO closure. Recommendations should be made on a case-by-case basis based on the DCS event(s), the type of diving being performed by the diver involved, and the risks of PFO closure.
Dr. Douglas Ebersole, MD is a cardiologist specializing in coronary and structural heart interventions at the Watson Clinic LLP in Lakeland, Florida. He is also an avid technical, cave, and rebreather diver and instructor. He can be reached at email@example.com.
- Wilmshurst, PT, Byrne JC, Webb-Peploe MM. Relation between interatrial shunts and decompression sickness in divers. Lancet. 1989;334:1302-1306
- Torti SR, Billinger M, Schwerzmann M. Risk of decompression illness among 230 divers in relation to the presence and size of patent foramen ovale. Eur Heart J 2004;25:1014-1020
- Bove AA. Risk of decompression sickness with patent foramen ovale. Undersea Hyperb Med 1998;25:175-8.
- Hagan PT, Scholz DG, Edwards WD. Incidence and size of patent foramen ovale during the first 10 decades of life: an autopsy study of 965 normal hearts. Mayo Clin Proc 1984;59:17-20.
- Kerut EK, Norfleet WT, Plotnick GD, Giles TD. Patent foramen ovale: a review of associated conditions and the impact of physiological size. J Am Coll Cardiol 2001;38 (3): 613-623.
- Wilmhurst PK, Ellis BG, Jenkins BS. Paradoxical gas embolism in a scuba diver with an atrial septal defect. Br Med J (Clin Res Ed) 1986;293:1277
- Moon RE, Camporesi EM, Kisslo JA. Patent foramen ovale and decompression sickness in divers. Lancet 1989;1:513-14.
- Germonpre P, Dendale P, Unger P, et al. Patent foramen ovale and decompression sickness in sport divers. J Appl Physiol 1998;84:1622-6.
- Germonpre P, Hastir F, Dendale P, et al. Evidence for increasing patency of the patent foramen ovale in divers. Am J Cardiol 2005;95;912-15.
- Gempp E, Blattearu J, Stephant E, et al. Relation between right-to-left shunts and spinal cord decompression sickness in divers. Int J Sports Med 2009;30:150-3.
- Schwerzmann M, Seiler C, LippE, et al. Relation between directly detected patent foramen ovale and ischemic brain lesions in sport divers. Ann Intern Med 2001:134:21-4.
- Schuchlenz HW, Weihs W, Hackl E, Rehak P. A large Eustachian valve is a confounder of contrast but not of color Doppler transesophageal echocardiography in detecting a right-to-left shunt across a patent foramen ovale. Int J Cardiol 2006;109:375-80.
- Gin KG, Huckell VF, Pollick C. Femoral vein delivery of contrast medium enhances transthoracic echocardiographic detection of patent foramen ovale. J Am Coll Cardiol 1993;22:1994-2000.
- Klingmann, C, Rathmann N, Hausmann D, et al. Lower risk of decompression sickness after recommendation of conservative decompression practices in divers with and without vascular right-to-left shunt. Diving and Hyperbaric Medicine 2012;42(3):146-150.
- [Swiss Underwater and Hyperbaric Medical Society. Empfehlungen 2007. Der Schwiezerischen Gesellschaft Fur Unterwasser-und Hyperbarmedizin Zum Tauchen Mit Einem Offenen Foramen Ovale]
[cited 2012 June11]. Available from: http://www.suhms.org/downloads/SUHMS%20PFO%20Flyer%20d.pdf(German)
- Scott P, Wilson N, Veldtman G. Fracture of a GORE HELEX septal occluder following PFO closure in a diver. Catheter Cardiovasc Interv 2009;73:828-31.
- Wahl A, Praz F, Stinimann J, Windecker S, Seiler C, Nedeltchev K, et al. Safety and feasibility of percutaneous closure of patent foramen ovale without intra-procedural echocardiography in 825 patients. Swiss Med Wkly. 2008:138:567-72.
- Saguner AM, Wahl A, Praz F, et al. Figulla PFO occlude versus Amplatzer PFO occlude for percutaneous closure of patent foramen ovale. Catheter Cardiovasc Interv 2011;77:709-14
- Furlan AJ, ReismanM, Massaro J, et al. Closure or medical therapy for cryptogenic stroke with patent foramen ovale. N Engl J Med. 2012;366:991-9.
- Billinger M, Zbinden R, Mordasini R, et al. Patent foramen ovale closure in recreational divers: effect on decompression illness and ischaemic brain lesions during long-term follow-up. Heart. 2011;97:1932-7.
A must have for all rebreather divers
The TDI Preflight Check List holds the essential standardized steps that must be completed for safety on a rebreather directly before entering the water. After assembling a rebreather based on the manufacturer’s recommendations using their check list, the rebreather may sit turned off while in transit to the dive site.
This “preflight check list” adds a short sequence to go through in order to make sure necessary components of the unit are on and functioning directly before entering the water. The TDI Rebreather Preflight Checklist can increase diver safety by making sure the user does not skip vital steps before entering the water.
We have also created a library of rebreather check or build lists to make it easier for TDI Rebreather divers to have access to their checklists on the go.
Click on the Rebreathers below for their unit specific checklist.
Challenge your preconceptions and read on with an open mind!
BY STEVE LEWIS
(Excerpted from “The Six Skills and Other Discussions”, Techdiver Publishing, 2011)
Philosophers have argued for centuries about how many angels can dance on the head of a pin, but materialists have always known it depends on whether they are jitterbugging or dancing cheek to cheek.
Thomas Eugene Robbins, American Post-Modern Author and Essayist, July 22, 1932
In staged decompression diving there is no perfect decompression schedule; therefore, there can be no guarantee that even when we do everything according to the book we will be protected from the vagaries of decompression stress1. To add dramatic emphasis to the situation, it appears that none of the players in the technical diving community can agree on which book to work from. Surprisingly, even though there are few definite answers and little in the way of absolute consensus on topics relating to decompression theory, the tech community does agree emphatically on one issue: the risk of getting bent is present on every dive and never, never goes away.
The message to those of us who have opted to engage in scuba diving, especially staged decompression diving in whatever form and flavor, is that we must accept that we are human lab rats engaged in a huge open-source experiment, and that it might be wise to take notes because somebody really should be keeping track of what’s happening to us.
The odd thing about decompression is that what works one day may not work a week later, and what works for you may leave me bent like a pretzel. Furthermore, a practice or behavior adopted and sanctioned by today’s experts may in fact be based on science as shaky as the addled ravings of a sixteenth-century alchemist and by next month be exposed as abject stupidity.
In practice, decompression can also appear to defy everyday logic. For example, if a set of dive tables suggests a diver stops his ascent at nine metres (30 feet) on his way to the surface, making arbitrary extra stops deeper in the water column in a bid to “add conservatism” can in reality do the opposite and cause him serious additional decompression stress.
In short, decompression is a crap shoot2 and in the experience of many who conduct this type of recreational dive, getting it right involves a certain level of wet-finger-in-the-wind estimation and the offering of silent prayers.
But there is some help available. For instance, there is a growing body of data about successful and unsuccessful technical dives collected and available for study thanks to a growing body of technical divers. Admittedly, these data are a statistician’s nightmare because of the wobbly methods used to collect them, but they have helped to inform a sort of best-guess behavior when it comes time to plan a staged decompression dive. Few of these practices are founded on real science or follow any rigorous third-party scrutiny, but they seem to work reasonably well for the vast majority of those of us who engage in diving to “great depths for a long time.”
With that in mind, l would like to share with you a few of those best-guess, seat-of-the-pants practices that relate to decompression planning, specifically something called variously Deco on the Fly or Contingency Decompression or Controlled Ascent Behavior. I believe that understanding this and the thinking behind it may help stack the odds in a dive team’s favor whenever a decompression dive is planned, especially in the event that something goes wrong during that dive and the carefully crafted plans are ripped up by Murphy.
A DAY LABORER’S PRIMER ON DECOMPRESSION THEORY
You may be a seasoned pro with a bunch of tech dives behind you, an experienced sport diver who is curious about tech diving or a rank novice who has just wrapped up open water certification; in a few cases, you may never have done a single dive and are just curious to find out if diving is your cup of tea. Whatever the case, let’s take a few minutes to do a short, what’s-what and who’s-who of decompression theory and its practical application. 3
Since John Scott Haldane’s first iteration of a dive table, built a little more than a hundred years ago on intuition, self-experiment and input from several farmyard animals and Royal Navy ratings, an assorted collection of interested parties have been researching the perfect decompression model. The list of participants includes military personnel, physicists, assorted medical doctors including several anesthesiologists and hyperbaric specialists, mathematics majors, at least one helicopter bush pilot, several computer programmers, a handful of statisticians, and one or two lay people. As a result the average diver is spoiled for choice, and there are decompression models of many shapes and sizes on the market. Surprisingly, the majority work, and for the simple tasks asked of them by most divers around the world, each of them is serviceable to some degree or another.
Almost all the decompression tables available to the rank and file recreational diver are based on a simple mathematical construct that tries to model the physiological effects of breathing compressed gas at depth and then ascending back to the world of one solitary atmosphere4. Essentially most of the decompression algorithms in general use by the tech diving community attempt to track inert gas uptake and off-gassing in a diver’s body relative to variations in gas density, ambient pressure and time using rather simple mathematics. (If you are thinking this sounds like a job for Differential Calculus Man, come up to the front of the room and help yourself to a Marvel Comic).
In the 100 years or so that these things have been evolving, there have been many major forks in the road to decompression Happy Land. The work of Professor Albert Bühlmann, Max Hahn, David Yount, Eric Maiken, Erik Baker, Bruce Weinke, Anders Ersson, et al is thought-provoking, sometimes contentious, and above all gives armchair decompression theorists fodder for the technical diving community’s analogue of a university faculty cocktail party debate. The acolytes for each side can argue gas kinetics, dual phase vs. dissolved gas models, the role of inflammatory response to hyperbaric trauma in multi-day deco diving, the efficacy of deep stops, and a whole bunch more theoretical stuff among themselves until their dates pass out from sheer boredom… all of which is beyond the scope of this article.
I want us to consider instead the suggestion that when we stand back and look at the collective outcomes of all the various algorithms and theories, tables and schedules we have to choose from, there is common ground among them. In fact, if we were to get a collection of decompression schedules for the same dive from a handful of different decompression models and compare them side-by-side, we might notice that each has a particular shape to it. If we traced a graph tracking depth over time, the curve of each schedule would be slightly different but each would follow a similar shape: a variety of flat parabolic curve.
What, then, if we were to learn the shape that curve makes? Could that help us to understand decompression better? Would we be able to execute seemingly complex ascents from deep trimix dives more fluidly and with more fluency if we understood the mechanism that dictates the shape of that curve?
I think we can, and I believe that learning the shape of a decompression curve is a simple and abundantly useful exercise. I’ve heard this technique called Deco on the Fly, Ratio Deco, Seat of the Pants Deco, Pie Deco, and Contingency Deco. All attempt to do the same thing, which is to build an ascent strategy that will mimic one drawn out ‘longhand’ with the help of decompression software or hard tables.
Just to be clear, I am not suggesting that this technique — let’s call it Deco on the Fly — replaces cutting a set of well-defined tables with proprietary decompression software or using one of the ready-made decompression tables available at your local dive store. Rather, that by knowing the trick of Deco on the Fly and how to manage your ascent behavior to fit a regular standard pattern, you will have a tool to help you sense-check the output from your favorite decompression planner. More importantly perhaps, you will also have an ace up your sleeve should you need to win a hand or two when playing cards with Murphy.
Allow me to explain.
THE FIVE WAYPOINTS AND SIMPLE ASCENT BEHAVIOR
At first glance from a diver used to making nothing more than three- or five-minute safety stops on her way back to the surface, a full decompression schedule can look confusing and terribly complicated, especially when the first stop called for is deeper than the sanctioned sport diving limit.
Regardless of how complicated an ascent looks, the journey from a dive’s maximum depth (or average depth) to the surface can be broken into bite-sized segments. This goes for ALL recreational dives whether they take place in 100 feet or 100 metres. The secret lies in first identifying five fundamental waypoints that all dives share:5
- 1Planned Maximum Depth or Actual Average Depth
- Off-Gassing Ceiling
- First Running Stop
- Staged Decompression Stop(s)
- Surface and Surface Interval Time (an often neglected but important part of all staged decompression dives)
The diver’s behavior between these waypoints conforms to another set of fixed values that works for all dives. It is that the diver ascends at nine metres or 30 feet per minute but no slower, between waypoints one and two, and nine metres or 30 feet per minute but no faster between waypoints two and three. The diver then moves at three metres or 10 feet per minute between three and four, and once the last stop is completed (usually at either six metres or three metres – that’s 10 or 20 feet), he will go slowly to the surface no faster than three metres or ten feet per minute.
That seems easy enough, so let’s add one small refinement to make it more applicable to technical diving.
Running stops6 are a series of brief stops that characterize ascent schedules typical of decompression profiles kicked out by dual-phase algorithms. For our purposes, the first stop and the last stop in the series should each be two minutes. The remainder need to be one minute stops. This effectively is the same as saying the diver moves between waypoints three and four at three metres per minute, with a one minute stop at the first running stop and the last. Either way, the transit time between the two waypoints will add up to the same number of minutes.
Now waypoint four – staged decompression stops – is the only other thing to look at more closely. Everything up to this point is essentially the same regardless of the dive’s profile. That is to say that every dive has a maximum or average depth, an off-gassing ceiling, running stops (or at least a portion of the ascent where the diver should slow down from nine metres a minute to three a minute), and a surface interval. Whereas sport dives have a single, simple safety stop, the dives we are discussing have at least one, and probably more, staged decompression stops intended to allow some time for the excess gas(es) in the diver’s body to be expelled during the normal breathing cycle. Waypoint four is something that varies from dive to dive, and we can use Deco on the Fly to work it out.
WAYPOINT FOUR: DECOMPRESSION STOPS
When we want to create an ascent schedule based on Deco on the Fly principals there are a few simple ‘guidelines’ we must work within:
- Remove as many variables as possible (standard ascent behavior, standard gases)
- This system works for dives between 42 metres and 75 metres
- The off-gassing ceiling is 1.5 bar (one and a half atmospheres, 15 metres or approximately 50 feet) shallower than the max depth
- Running stops can start immediately above or up to 10 metres above the off-gassing ceiling7
- Running stops are one or two minutes long and the maximum number of running stops is five
- Gas switches must be made according to the schedule. If a gas switch is off-schedule, reset the clock starting at the point where EACH team member is on the “new” gas
- Spend at least four minutes at the depth where gas switches are done. Follow the normal shape of the curve at the next stop
- A staged decompression stop’s duration is a minimum of three minutes
- Decompression stops are part of a short series that conforms to a simple mathematical pattern that is unique for each gas
- Each series consists of blocks of five numbers that fit within the operational limits of a decompression gas and consists of five evenly spaced stops, the total duration of which adds up to a specific ratio of the total bottom time
- Patterns or Curves repeat through the range of each decompression gas used during ascent
- A close fit works; do not fret details as long as the total time spent completing each series of stops adds up to the required value
- Take notes. Always track what works for you. Deco on the Fly is a guideline and there is nothing sacrosanct about it. Where there is a degree of latitude, write down what worked and if you have to do it again, follow a similar approach.
The reasons for explaining the concepts behind this are simply to open your minds up to different ways of looking at dive planning and dive execution. I dive with tables output by V-planner for my personal dives. Deco on the Fly is my fall-back plan and the concepts behind it merely help me to understand what those V-planner schedules are telling me. Deco on the Fly helps me to control my ascent behavior and, I believe in conjunction with all the other best practices such as hydration and rest, helps me to maintain a 100 percent success rate pulling off decompression dives without incident. I can make no predictions or recommendations regarding how it might work for you. None. The truth is that Deco on the Fly may put you in a similar position to a store-bought guinea-pig being taken to a Peruvian BBQ. Please be warned.
In closing, let’s review a few points that relate to decompression planning in general.
- ecompression algorithms are just pure mathematics trying to model biology
- Biology is weird and is difficult to model with pure mathematics
- Decompression theories contain varying amounts of guesswork – some more than others since goats and Jell-O do not supply intellectual feedback
- Given all the above, you realize and accept that by conducting staged decompression dives, you have become part of the experiment. TAKE LAB NOTES!
- Decompression theory is constantly being refined (The only constant is change)
- There is no such thing as a foolproof decompression schedule
- Decompression is affected by several variables: some, like hydration, we can control, and others we cannot.
- Whenever you exit the water after a staged decompression dive – and regardless of what your decompression schedule or (gods forbid) your computer is telling you – LISTEN to what your BODY is TELLING YOU.
- Given a few basic rules and some simple “memory work” almost anyone can produce a decompression schedule on the fly that’ll work… sometimes.
So now that your curiosity and desire to know more has been peaked… please visit www.tdisdi.com to find a TDI Instructor to meet your particular educational needs. Who knows how “deep” your interest will take you…but not till you have the proper training!
This article was based on and is an excerpt from “The Deco Curve: Controlled Ascent Behavior and Contingency Decompression on the Fly” a chapter from the successful book by Steve Lewis called “the Six Skills and Other Discussions.” This book is available at select dive stores and through onLine stores such as Amazon and Create Space eStore via: https://www.createspace.com/3726246.
1 Decompression stress describes the collective issues of Decompression Illness, Decompression Sickness, and perhaps most importantly, sub-clinical bends and bubble problems.
2 The phrase: “Decompression is a crap shoot!” is a phrase attributed to Bill Hamilton and John Crea when, as experts on decompression theory, they made a presentation to an early assembly of tech diving enthusiasts
3 For a much more definitive study of this topic, I suggest adding Deco for Divers: Decompression Theory and Physiology by Mark Powell and Deeper into Diving by John Lippermann and Simon Mitchell to your personal library and reading both from cover to cover.
4 The notable exceptions are models based on statistical analysis of risk and known collectively as probabilistic tables. The math used to predict a diver’s outcome from a specific dive does not attempt to model gas kinetics but instead present those who use them the option to conform to dive profiles that have an estimated degree of risk of DCS based on the outcome of similar dives.
5 These waypoints and basic ascent behavior were first introduced in Chapter Four.
6 Christened deep stops when the concept was introduced to modify old Haldanian style “bend ’em and mend ’em” ascent schedules
7 For examples here, I have used six metres (about 20 feet) for the interval between waypoints two and three. This helps to produce schedules that correspond closely with decompression curves from V-Planner software (a VPM-B algorithm) set at +3 or +4 conservative level.
Captain Paul Watson, founder and president, Sea Shepherd Conservation Society
The one thing that I have been most proud of in my long career is the fact that after 35 years of interventions to defend marine life we have not caused a single injury to any person nor after some 350 voyages have I had any of my crew seriously injured. I am also proud of the fact that although we have been aggressively intervening against illegal whalers, sealers, dolphin killers, drift netters, trawlers, turtle killers and other ocean life-destroying enterprises, we have always done so within the boundaries of the law.
We have launched and carried out eight campaigns to oppose the Japanese whalers arrogantly operating in the Southern Ocean Whale Sanctuary. We have not caused a single injury to any of them nor have we caused any damage to their ships. The whalers on the other hand have shot at us, rammed our ships and completely destroyed one of them without any legal consequences whatsoever. What we have done is to cripple them financially by blocking their ability to kill whales and the achievement that I am most proud of is that due to our interventions some 4,000 whales would now be dead if not for the courageous efforts of my incredible crews.
Our objective from the beginning of the campaign was to sink the Japanese whaling fleet economically. We have achieved that. We have bankrupted them and driven them into debt; and the whaling fleet, weaker now than ever, only survives due to massive subsidies from the Japanese government.
I have never been under any delusion that taking on one of the world’s great economic superpowers would not have consequences for us, especially since we have so humiliated the whalers at sea, outmaneuvering them and chasing them out of the Southern Ocean Whale Sanctuary with their kill quotas denied and their profits wiped out.
And of course the two events that could not be anticipated in our overall strategy have caused us the most problems.
The first is the Japanese tsunami.
Of the hundreds of millions of dollars contributed from around the world to the victims of that disaster, an allocation of some $30 million dollars was given to the whalers to fight Sea Shepherd Conservation Society. That is certainly not what the people who sent donations ever imagined that their contributions would be spent on. Rebuilding houses, food, medicine, repairing the infrastructure yes, but to subsidize the operations of the whalers to continue killing whales in a sanctuary – who could have foreseen such a betrayal of trust?
With that money the whalers have hired public relations firms, increased security, and initiated lawsuits. However, the increased security on their fleet failed to prevent Sea Shepherd from once again intervening and as a result the whalers took only some 26% of their intended kill and once again lost all possible profits, sinking even deeper into debt.
The filing for an injunction against Sea Shepherd in the United States courts also failed when the U.S. Judge denied their request for a preliminary injunction and although they are appealing the decision, their chances for success are slim.
They are forcing Sea Shepherd to expend funds on legal fees but such expenses are all part of the overall battle plan and our success at sea is bringing in more and more support, allowing us to continue our fight against their poaching activities both on the water and now in the court.
The tsunami funds have also been used to find strategies to defeat us and one of them was to track down a decade-old incident off Guatemala where we had intervened against an illegal Costa Rican shark-finning operation with permission of the Guatemalan government. The charges had been dismissed back then after the Costa Rican court reviewed our documentation, and the incident has been viewed by hundreds of thousands of people in the award-winning documentary film, Sharkwater. But with a little persuasion from Japan, Costa Rica decided to resurrect the incident with a charge that we had sprayed water onto the shark-finning boat causing them to lose control and to collide with my ship. Even so there were no injuries and their vessel was not damaged. Hardly an extraditable offense.
When first filed with Interpol by Costa Rica, the request was denied. But when I landed in Germany on May 13th, the Germans decided to act on the request despite the dismissal and detained me. My suspicions right from the beginning were that this was a Japanese initiative and once Japan saw that Germany was willing to act on a bilateral basis with Costa Rica they approached Germany with their request for extradition.
When a reliable source within the German Ministry of Justice tipped me off that the Germans would arrest me the next morning when I reported to the Frankfurt police I knew that once sent to Japan, I would not be leaving for a very long time. Thus I made the decision to depart Germany.
I was also sent a copy of the Japanese request by this German source, and the entire case by Japan is based upon accusations against me by Peter Bethune.
This was the second unforeseen incident.
During Operation Waltzing Matilda (2009-2010), the Ady Gil, skippered by Pete Bethune, was deliberately rammed and sliced in half by the Shonan Maru No. 2. Pete Bethune decided to board the Shonan Maru No. 2 to confront the Japanese captain. In one of the episodes of Whale Wars, I advise Bethune not to board the vessel. His reply was that it was what he needed to do, it was his ship and he had the right to demand that the Japanese captain answer for the destruction of the boat. Bethune said he would take complete responsibility for his actions and thus he boarded the vessel with his own Jet Ski and assisted by his own crewmember.
Bethune was taken to Japan and instead of taking full responsibility for the decision he made, he accused me of ordering him to board the Shonan Maru No. 2. This was a deal he made with the prosecutor in return for a suspended sentence. Our legal team has documented evidence of this deal.
My critics can say what they like but I think that any objective review of the facts within the context of our history will show that these demands for my extradition are politically motivated and not based on a proper legal investigation. Everything that happened during the Costa Rican incident was documented by independent filmmaker Rob Stewart for the making of the film, Sharkwater. Everything that has occurred with reference to Japanese whaling operations in the Southern Ocean Whale Sanctuary was documented for the Animal Planet program Whale Wars and in the film, At the Edge of the World. The Sea Shepherd Conservation Society operates overtly and above board. Everything we do is documented.
For those critics who say that I should therefore submit myself to Costa Rica or Japan if I have nothing to hide I can only say that would be an option if allowed the opportunity for a fair and impartial trial. I do not believe that either country would give me a fair and impartial trial and even if acquitted by a Costa Rican court, they would then turn me over to Japan. Japan is not seeking justice, they are seeking revenge.
What we have here is a Japanese captain having completely destroyed a 1.5 million dollar vessel, injuring a cameraman and almost killing six crewmembers. The crew was recruited by Pete Bethune to help man his vessel, the Ady Gil, and were not Sea Shepherd crewmembers, but Sea Shepherd still worked with them to try to stop the Japanese whalers and Sea Shepherd rescued them when their ship was rammed and destroyed. Note that Pete Bethune was not a Sea Shepherd Captain either. In fact, I have no doubt that had a Sea Shepherd Captain been in command of the Ady Gil that day, the collision would have been prevented altogether. But that was not the case and the collision occurred, yet the Captain of the Shonan Maru No. 2 has not even been subjected to questioning over this incident. This in contrast to charges against me that do not even involve activities by myself based solely on the accusations of a man who made a deal with the Japanese in return for a suspended sentence.
With regard to Costa Rica, the courts have seen the evidence and questioned me and the witnesses and gave me a clearance to depart Costa Rica in 2002 and then revived the charges a decade later at the same time that a meeting took place between President Chinchilla of Costa Rica and the Prime Minister of Japan.
Click here to view the 2002 Ship’s Log Citing Clearance for Departure from Costa Rica (PDF)
Other incidents by Japan have also not been investigated including the ramming of the Bob Barker by one of the harpoon vessels, and the collisions with the harpoon vessels and the Steve Irwin when the whalers attempted to force the Sea Shepherd vessel away from blocking the stern slipway of the Nisshin Maru.
For myself, I have to weigh the best course of action within the context of our overall strategy to defend and protect the Southern Ocean Whale Sanctuary. If I surrender myself to Japan and/or Costa Rica I will not be in a direct command position to intervene against the Japanese whale poachers in Antarctic waters. I can coordinate the campaign from a land base or from onboard ship but it will not be possible to do so as a prisoner of the Japanese. Operation Zero Tolerance must be my primary concern and it is towards launching that campaign that I have decided to dedicate myself. If detained prior to the launch, the campaign will proceed under the directions given through the campaign chain of command. After the campaign if the legal issues remain outstanding I will address them directly at a time of my choosing with guidance from our legal team.
Another bit of misinformation is that I am fugitive from justice. I am not, and it is not a crime for anyone to work with or assist me. It is a complicated case, but I am not wanted outside of Japan, Costa Rica and Germany. There is no arrest warrant for me outside of these three countries and with regard to Germany, I have not broken any German law. Skipping bail is not a crime in Germany independent of the charge that was the cause of my being detained.
Presently I am in a place where I cannot be touched by the Interpol “red” notice and our legal team is working on exposing the local warrants from Costa Rica and Japan as being politically motivated with the objective of having Interpol disregard them. I believe that any impartial review of the evidence will exonerate me and it is best to have this evidence reviewed with impartiality rather than to throw myself at the mercy of courts where the verdict has already been determined.
From the beginning of this campaign to oppose the Japanese whale poachers in the Southern Ocean I was well aware that there were extreme risks involved. In addition to operating in the most hostile marine environment on the planet we were also aware that we were engaging one of the world’s wealthiest and most powerful nations.
Despite this, every year we have gotten stronger and the whaling fleet has become weaker. And most importantly our efforts to defend the whales, to save their lives has increased dramatically to the point where the Japanese have failed for two years in a row to kill more than 70% of their no longer defenseless victims.
And thus we come down to the showdown and the reason we call this Operation Zero Tolerance. Our goal this year is to achieve zero kills and we will do all within our power to make that goal a reality. It is expected that the Japanese will do whatever they can to stop us and one of their tactics is to eliminate me as the leader of this campaign. They may or may not do so but either way they cannot stop the passion of my officers and crew who will stand with me or who will stand if need be, without me. But stand they will and our ships will once more engage these ruthless killers on the high seas to shield the gentle giants from their merciless harpoons.
If I am captured and politically crucified before this campaign all I can say is that this has always been for me a possibility and the Japanese will find that I am not as meek and unprepared as their previous prisoner. The loss of my personal freedom or even my life will be a fair price for achieving the objective of realizing the security of the Southern Ocean Whale Sanctuary. And with or without me that goal will be realized because we have something the Japanese whalers will never have. That is an absolute passionate respect for life and for maintaining the integrity of the Sanctuary. They are motivated by greed. We are motivated by love, and love and respect for life will always triumph over greed and death.
To all of our supporters worldwide – thank you. Your support gives us the means to go forth, where we need to go to fight this battle. Thank you also to our crew of Cove Guardians who have begun their six months in Taiji, Japan to defend the dolphins. Thank you to our crew in Africa defending the seals, to our crew in the Galapagos defending those enchanted isles, to our crew in the Mediterranean defending the endangered Bluefin tuna, our crews in the South Pacific defending sharks and coral reefs and to all those Sea Shepherd warriors initiating fundraising, public awareness and activist campaigns for oceanic species worldwide.
I am honored to work with each and every one of you. Together we are a force that has demonstrated and will continue to demonstrate that we can make a difference, and that no matter what the obstacles or how impossible the mission, we will not back down. Martin Sheen once told me that when someone accused him of supporting a lost cause that “lost causes are the only causes worth fighting for.” Martin, myself, and all of our crew are united in this belief that the impossible can become possible. And it is the passion, courage, imagination and resourcefulness of my incredible crew that will win this fight for the whales and for the oceans.
I’m proud of them all and most honored to have served this cause to protect our oceans, for the one most basic of truths is this: If the oceans die, we die! It is as simple as that and, thus, to me, there is no cause more important.
Divers are like sharks. We both breathe underwater, have stereo vision and depth perception, and we both use fins to propel ourselves effortlessly through the water. Have you ever tried diving without fins? Ridiculous. Unfortunately 100 million sharks lose their fins each year, but unlike us, they can’t survive without their fins. So to support international anti shark-finning campaigns, divers in Koh Tao, Thailand, are preparing to ditch their fins in order to swim 3 km around an island, fin-less.
Sharks, like many of the larger predators, have been given an exaggerated negative media impression which has led to a common fear that they are a threat to humans. Media latches onto any and every shark attack and the news goes worldwide. In fact, you are more likely to be killed by a vending machine. And when was the last time you read about a savage killer vending machine. Additionally, the human perception for protecting ‘cute and cuddly’ over ‘wet and slimy’ means shark conservation is often neglected and arduous. Sharks are apex predators and without them there would be aquatic chaos; the fine balance of our marine ecosystems relies upon these behemoths of the deep to keep order. And as an observational sport, seeing a beautiful, healthy reef is fundamental to the activity and business of diving.
More than 100 million sharks are killed each year, either inadvertently as by-catch during trawl net fishing, through habitat destruction, sport fishing, or by the more barbaric practice of ‘shark finning’. Many asian cultures consider the consumption of a sharks fin to possess spurious health benefits. This has lead to a multi-million dollar industry for shark fin soup, with 10,000 tonnes of shark fin landed annually. With an immense economic incentive for shark finning (a large whaleshark pectoral fin can sell for US$15,000), it’s no wonder conservation agencies are having a hard time controlling the international trade of sharks. And as shark populations become more depleted, so their value increases.
Within the last few decades human impact has destroyed 90% of the global shark population. And that’s only the ones we have effectively monitored – shark research, like their conservation, is extremely limited and complex. It is impossible to know what we are inadvertently doing to the ocean abyss when we haven’t even been able to explore it yet. And existing data is limited and consequential, taken from the few scientists trained in marine research or from corrupt fisheries data.
Many politicians have fought for protection of sharks, but insincere data and the buying of many countries votes by countries benefiting for the killing of sharks makes international trade control weak, if at all. Without appropriate advice from those that can access the aquatic realm as best as any human, the divers, there is little support for their protection over economic gain.
As divers we are the ambassadors to the underwater world. We have the skills in place and the appreciation of the aquatic realm to be the best advocates for shark protection. The scale of the problem can often lead to the mindset that we can’t make a dent. But the truth is every small effort to help sharks will contribute; we can measure our success in the awareness we generate, the minds we change, and the sharks we save. There are lots of ways to help get involved in shark conservation; enrol on marine identification and conservation specialty diving courses; educate fellow divers on the problems facing sharks; participate in ongoing conservation action in your local dive school; and organise fundraisers and awareness evenings. Sign a petition supporting a tighter control on the international protection of sharks; it does a global species little good to be protected in the waters of one country, only to be freely butchered when they wander into the waters of another.
As a member of the Shark Alliance, Big Blue Conservation (Koh Tao) have organised a Swim for Sharks, which last year raised 17,000 baht for shark conservation activities supporting tighter control for the international trade of sharks. This year divers all over Koh Tao will be participating in the annual Swim4Sharks, swimming the 3 km around Koh Nang Yuan Island in the Gulf of Thailand and raising the awareness of the whole island with night time entertainment, including a mass Mohawk shaving – very shark fin-esque. Please give some time (and your hair) to shark conservation, come along and see how a small diving community can have a big impact for shark conservation.
As divers, that first sighting of a whaleshark is euphoric; watching the 10 tonne plankton feeder glide gracefully around the reef; pause and play in your regulator bubbles; approach you with inconceivable curiosity; there’s nothing like it. We know sharks are not out to hunt humans – we are in their realm and we should give them the respect they truly deserve from 400 million years of existence. We are guests of the oceans not customers. And I don’t know about you, but I quite like seeing sharks in their domain going about their daily activities. I’d quite like to keep on seeing them.
Working with University of St. Andrews science teams, divers found remains of a huge area of land that stretched from Scotland to Denmark and slowly submerged by water.
The ‘drowned world’ is said to have been the ‘real heartland’ of Europe, housing tens of thousands of people in an area that stretched from Northern Scotland across to Denmark and down the English Channel as far as the Channel Islands.
Once roamed by mammoths, Doggerland was hit by ‘a devastating tsunami’, the researchers say.
“The name was coined for Dogger Bank, but it applies to any of several periods when the North Sea was land,” said Richard Bates of the University of St. Andrews.
“Around 20,000 years ago, there was a ‘maximum’ – although part of this area would have been covered with ice. When the ice melted, more land was revealed – but the sea level also rose.
“Through a lot of new data from oil and gas companies, we’re able to give form to the landscape – and make sense of the mammoths found out there, and the reindeer. We’re able to understand the types of people who were there.
“People seem to think rising sea levels are a new thing – but it’s a cycle of Earht history that has happened many many times.”
Bones found by North Sea fishermen had prompted speculations about the existence of the lost land, but the there were no clues as to how it looked like.
“We have now been able to model its flora and fauna, build up a picture of the ancient people that lived there and begin to understand some of the dramatic events that subsequently changed the land, including the sea rising and a devastating tsunami,” Bates explained.
The St. Andrews, Dundee and Aberdeen universities have now displayed the results of their 15-year-project on the lost land in an exhibition in London.
The show will display artifacts recovered from the seabed at the Royal Society Summer Science Exhibition until July 8.
Visitors can see an interactive video showing them how the land might have looked with hills and valleys, large swamps and lakes with major rivers dissecting a convoluted coastline.
“There is actually very little evidence left because much of it has eroded underwater; it’s like trying to find just part of a needle within a haystack,” said Dr. Bates.
“What we have found though is a remarkable amount of evidence and we are now able to pinpoint the best places to find preserved signs of life.”
Sharks ensure our very survival
The frightening reality is, like them or not, sharks play a crucial role on this planet. Remove sharks from the oceans and we are tampering with our primary food and air sources.
Sharks keep our largest and most important ecosystem healthy. Our existence, in part, is dependent upon theirs. Sharks have sat atop the oceans’ food chain, keeping our seas healthy for 450 million years. They are a critical component in an ecosystem that provides 1/3 of our world with food, produces more oxygen than all the rainforests combined, removes half of the atmosphere’s manmade carbon dioxide (greenhouse gas), and controls our planet’s temperature and weather.
The shark’s critical role
As the apex predators of the oceans, the role of sharks is to keep other marine life in healthy balance and to regulate the oceans. Remove sharks and that balance is seriously upset. Studies are already indicating that regional elimination of sharks can cause disastrous effects including the collapse of fisheries and the death of coral reefs.
Photo: Rob Stewart
A world without sharks?
One study in the U.S. indicates that the elimination of sharks resulted in the destruction of the shellfish industry in waters off the mid-Atlantic states of the United States, due to the unchecked population growth of cow-nose rays, whose mainstay is scallops. Other studies in Belize have shown reef systems falling into extreme decline when the sharks have been over fished, destroying an entire ecosystem. The downstream effects are frightening: the spike in grouper population (thanks to the elimination of sharks) resulted in a decimation of the parrot fish population, who could no longer perform their important role: keeping the coral algae-free.
What legacy will we leave for our children?
Future generation taking back their sharks! Photo: Jamie Pollack, sharkangels.org We don’t hear how the elimination of sharks might impact our best natural defense against global warming. Or how our favorite foods might disappear as a side effect of the extinction of sharks. Or that we could lose more oxygen than is produced by all the trees and jungles in the world combined if we lose our sharks. But we should.
If you care about Climate Change, you should care about the sharks.
No one knows for sure what will happen globally if shark populations are destroyed, but one should fear the results. Two hundred and fifty million years ago, this planet suffered the largest mass extinction on record, and scientists believe this was caused in part by catastrophic changes in the ocean. Sharks play a keystone role ensuring our seas remain in a healthy equilibrium and do not reach that point again.
This was used from Seashepherd.org
Big Blue Tech is proud to announce the release of new programs from IART (international Association of Rebreather Trainers).
IART, the International Association of Rebreather Trainers, was founded in 1997 after Hubert Stieve and Peter Grosserhode recognised that the growth of rebreather technology in recreational diving was not without great safety risks and organizational problems for the established recreational diver training agencies and clubs. Too great was the difference in required knowledge, ability und discipline.
IART quickly established itself as the leading rebreather training agency in Germany – its country of origin – and over the last two years, under the new management of Chris Ullmann and Neil Matthews, the organization has begun to spread rapidly to other lands. Regional Offices now exist for Scandinavia, the UK, Spain, Holland, Australia, the United Arab Emirates, Hong Kong and Thailand. These offices provide support for IART members as far afield as New Zealand and Micronesia and Scotland and Sweden.
IART has the aim, through uncompromising teaching standards, to further the use of Nitrox and Trimix and to make rebreather diving as safe as possible. These aims and the ways to achieve them are continually reviewed and adapted. IART has and will closely follow the future development of rebreathers and continue to make recommendations and promptly adapt its training programmes to keep pace with newly emerging technology.