Are you an Big Blue Tech Facebook Fan yet? If not, here is a good reason why you should. We’re now introducing a weekly contest where you can be the fan of the week.
What does it mean? Being an Big Blue Tech Facebook Fan is much more than reading our status updates, instead we want to hear from you and learn more about who you are.
Stating from today, every Saturday we’ll ask who wants to be our next fan of the week. All you have to do is head over to our Big Blue Tech Facebook Fan (click and become a fan if you already aren’t), and comment on our post telling us why you should be the next fan of the week. We’ll pick one lucky fan, who posted a comment, to be our fan of the week.
You will have the chance to brag in front of all other fans with a short interview. As a small incentive this week you’ll be awarded with Big Blue Tech T-Shirt sent to you from Thailand.
What do you think of this new promotion? Comment here on the blog and let us know how we can make it better. But now, hurry and head over to our Big Blue Tech Facebook Fan
Big Blue Tech recently completed a TDI Decompression Procedures and Advanced Nitrox Course for Kathryn Julia conducted over 5 days on Koh Tao Island by TDI Instructor Ash Dunn.
This training course combines the Advanced Nitrox and Deco Procedures Diver training courses to maximum training depths of forty-five meters (45msw) or one hundred fifty feet (150fsw) using Oxygen Enriched Air for bottom mixes and 50%O2 mix for decompression gas. The “built-in” 10 – 12 hours of theory time provides the diver a better grasp of Decompression Illness and Oxygen Toxicity concepts and be able to confidently come up with dive plans that further reduce risks of DCI and O2 Toxicity. The in-water skills and exercises introduce the student diver to innovative techniques in survival, self-sufficiency, and proper decompression management.
Divers often refer to decompression as a glass ceiling. Decompression diving is about passing this ceiling at the right time and doing so in a safe and competent manner. Below is a brief description of what decompression diving is, and some tips on for safer and better decompression diving.
Decompression diving refers to a dive that exceeds the usual decompression time/depth limits. The ourpose of decompression diving is really to allow divers longer on the bottom of where they are diving. It releases the diver from many of the restrictions that divers face. But the limiting of these restrictions also means the dive is open to greater risks, and requires the diver to be experienced and competent.What this means is that on the ascent the diver will need to make one or more decompression stops. If the diver fails to make the decompression stops then they can suffer from decompression sickness, or the bends.
Decompression diving isn’t for the occasional diving amateur, nor for those who do not wish to accept the risks that decompression diving can have. But for those who are experienced and able enough, below are some tips for making the most from decompression diving.
* Keep it simple. If you are beginning decompression diving, or this is your first dive don’t do anything complicated. No decompression dive should be planned with more than one stop on your ascent until you are completely comfortable with your own ability to maintain depth etc. Never do anything which you cannot control, or which exposes you to risk.
* Imagine every dive is a decompression dive. There is some evidence to suggest that every dive is really a decompression dive, or should be treated as such. Safety stops should be a part of any ‘normal’ dive as are slow ascents. Therefore many of the techniques that make a good diver, also make you a good decompression diver. That is a very good way t improve, and extend your diving abilities by ensuring you always following the best practice in every dive, which means you will be a safe decompression diver.
* Make sure you have the hardware. Most dive computers will allow you to plan some form of decompression dive. Start small, and trust in your computer as it isn’t going to cheat, give you a few more seconds, or just let you see whats round that rock! Oh. And please make sure you know and understand all of your computers decompression functions. You don’t want to
Many divers pursue a dream of diving in pristine waters untouched by civilization; to achieve that dream, they find themselves in locations hours and days from a medical facility that is capable of providing proper and specific treatment in case of decompression illness (DCI). Treatment of decompression sickness (DCS) appears to be most successful when divers are recompressed immediately after symptom onset, but most treated DCS cases improve regardless of the delay to treatment. On-site recompression chambers are generally not available except in commercial and military diving operations. As an alternative, occupational groups such as fishing divers of Hawaii and pearl divers of Australia have adopted in-water recompression (IWR) with reportedly good success. As a result, recreational divers often look upon the experience of these groups and ask if IWR should be used in recreational diving, too.
Supporters of IWR point out that early treatment and breathing of 100 percent oxygen under increased pressure can remove inert gas and gas bubbles before they cause permanent damage. They bring up positive experiences of occupational divers who used IWR, though they acknowledge a few known cases that resulted in complications. They also admit there are technical considerations not likely available in many recreational dive settings, including provider training and the fact that not all cases of DCS are appropriately managed with IWR.
In 1998, Divers Alert Network® (DAN®) and the Undersea and Hyperbaric Medical Society (UHMS) co-sponsored a workshop on IWR; the workshop prompted so much debate, it failed to produce a position paper. In 2000, the South Pacific Underwater Medicine Society (SPUMS) hosted a second public debate; this time the arguments of experts opposing IWR seemed to prevail.
Opponents argue that potential complications outweigh benefits. The data concerning IWR are anecdotal, and the reporting of outcomes may be prone to bias, with positive results being preferentially presented. Most cases of DCI in recreational diving are mild in nature and resolve even with delayed treatment. On the other hand, cases that could benefit from treatment are the most severe and require additional medical treatment such as critical life support, fluid resuscitation and other medical interventions not feasible underwater. In the most severe DCI cases, injury may occur before IWR can realistically be started in recreational diving conditions. In extreme cases, providing surface oxygen with additional treatment measures and medical assistance may be more beneficial than recompression and oxygen without additional treatment.
Ten years after the SPUMS debate, the opinions on IWR remain diverse.
Do you think in-water recompression should be used in recreational diving?
Dr. Edmond Kay: Victor Hugo once said, “There is nothing more powerful than an idea whose time has come.” In-water recompression is one of those captivating ideas I thought would have gained traction by now, given the number of experts who have embraced it.
IWR is indeed a compelling idea, and its use should be considered when diving in remote areas of the world, as long as adequate precautions are in place to ensure diver safety. IWR is not for everyone, however. It is most appropriate for the advanced diver, technical or commercial professional, or the military diver. Training requirements, equipment and support personnel make IWR inappropriate for casual recreational diving.
Dr. Alessandro Marroni: I believe there is no sufficient evidence to support this technique for general use in place of definitely safer methods, such as oxygen first aid and fluid administration, for which there is growing scientific evidence.
What are the most important considerations if IWR is attempted?
Kay: The requirements for safe IWR are well known. That said, there are serious consequences for the untrained and poorly prepared diver who tries to improvise. If strict procedures are not followed, the outcome could be tragic; fatalities are already a matter of record.
A good starting point for safe, controlled IWR is a full-face mask or hardhat with communications gear for the injured diver, a mandatory diver’s attendant and a surface tender. An ample supply of oxygen is also a requirement, along with a means of switching between air and oxygen.
In the unlikely event of oxygen toxicity, an in-water bailout to air (via a manifold or switching block) is easily accomplished by the attendant. The in-water attendant can then continuously monitor the condition of the injured diver and resume oxygen when the toxic effect has resolved.
Specialized equipment such as a dedicated underwater video camera and lighting for direct observation of both patient and attendant is optional but nice features for an advanced setup. Manpower needs include both surface support and rotating shifts of in-water attendants.
Marroni: The prerequisites [of IWR] are difficult to achieve, particularly in the recreational diving environment, and since the clinical evolution of DCI is often unpredictable, being underwater would imply additional danger in case of any complication.
What are some of the risks of performing IWR?
Kay: Hypothermia may not be a problem in warmer climates, but the shortest oxygen IWR treatment table is 2.5 to 3.5 hours and can extend to last for days. With that length of treatment, everyone needs thermal protection of some sort. A drysuit or dry “tube suit” with adequate undergarments, or perhaps even conductive polyamide electrically heated underwear, would do the trick in colder water. IWR treatment tables abound; the Australian and Hawaiian tables are cited most often.
Marroni: IWR can appear as an appealing, simple and quick remedy, especially to “expert” divers in denial of their symptoms, leading divers to ignore the potential for medical or logistic complications.
The downside of IWR is definitely more important than any potential benefit. It should not be considered unless it is extremely well preplanned with the necessary equipment ready at hand, underwater assistance by buddy divers ensured, and sheltered, warm waters in which the operations can take place with good surface-diver communication.
Another negative aspect of IWR is that it impairs the possibility for rehydration of the diver (fluids play an essential role, together with oxygen, in DCI first aid), potentially contributing to further dehydration.
Lastly, considering the current international guidelines for DCI first aid that recommend oxygen, fluid administration and timely evacuation to treatment facilities, one should not ignore the potential legal implications when suggesting or assisting in an IWR procedure.
When, if ever, should IWR be considered?
Kay: I firmly believe that we need to begin teaching the technique of IWR for remote area diving. Everyone seems to agree if a recompression chamber is available within a reasonable amount of time, it certainly should be used to treat DCI. The definition of “reasonable time to recompression” varies considerably with the concerns and biases of the expert commentator. A 12-hour delay in treatment is often cited as sufficient to consider IWR, but in truth, no one really knows how long a wait would make IWR appropriate. The sickest individuals need the most rapid recompression, but severity of DCI is often cited as a reason not to perform in-water recompression. In some of the remote regions of the world with no access to hyperbaric facilities, travel time to get to a chamber exceeds 24 hours, and transport is extremely expensive.
The amount of preparation and training that goes into IWR is considerable, but no more so than deep technical diving. The earlier DCI is treated, the greater the chance for complete resolution of symptoms. In many remote areas of the world, these techniques are put in use immediately upon recognition of DCI.
Marroni: In my many years of activity as a diving medical officer, I have witnessed many cases where IWR was attempted, and my personal experience is that in the majority of cases it did not produce significant improvements; in fact, in a good number of cases the procedure had to be aborted for logistical problems or medical complications.
Meet the Experts
Dr. Edmond Kay is the director of hyperbaric medicine at HealthForce Partners. He is a clinical assistant professor and diving medical officer for the University of Washington and is also medical director of Divers Institute of Technology. He is the project physician for a number of hyperbaric tunnels in Washington state and an advisor on the Nevada Lake Mead tunnel. He is a diving and hyperbaric physician trained by the National Oceanic and Atmospheric Administration and has been a diving medical examiner for UHMS, Health and Safety Executive, WorkSafeBC and the Diver Certification Board of Canada. He is board certified in both undersea and hyperbaric medicine and family medicine. In 1998, Kay co-chaired and edited the IWR workshop co-sponsored by DAN and UHMS.
Dr. Alessandro Marroni is the founder and president of DAN Europe as well as a member of the board of directors and president of International DAN. He serves as vice president of the European Committee for Hyperbaric Medicine (ECHM), president of the European Foundation for Education in Baromedicine, and secretary general of the European College of Baromedicine.
Marroni obtained post-graduate specialization degrees in occupational medicine, underwater and hyperbaric medicine, and anesthesiology and intensive care.
Marroni has academic teaching appointments at several universities and post-graduate programs. He has published more than 180 scientific papers, mainly in the area of underwater medicine research, with particular interest in the prevention of DCI in recreational diving.
No bubbles, compact designs and a different set of in-water skills make rebreathers an exciting option for experienced divers.
At first glance, a closed-circuit rebreather (CCR) can seem a bit surreal. The primary components — large breathing hoses, small high-pressure tanks, a “scrubber” canister, counterlungs and (on some units) multiple computers — all look like something found in a sci-fi movie. But take a closer look, and the system starts to make more sense. And when you begin to understand how a CCR works, you begin to see how this different way to dive can open up whole new frontiers of underwater exploration.
Open-circuit scuba is the most common technology used by divers; it is simple, reliable and easy to use. The scuba regulator reduces the high-pressure air in a diver’s tank down to ambient pressure so the diver can breathe. Exhaled gas is then released into the water column, basically wasted. Now this isn’t a bad thing, but in order to make longer or deeper dives it is necessary to carry a large gas supply. Double 80 cu ft (2,265 L) tanks weigh approximately 90 lbs (41 kg) and create considerable drag for the diver to push through the water. Another drawback: The noise created by exhaled gas can scare away marine life. The CCR Difference
Closed-circuit rebreathers use a different approach in supplying life support to the diver. At the heart of the system are the diver’s lungs, which move breathing gas through a closed, circulating loop. Every exhaled breath, of course, contains carbon dioxide and a diminished level of oxygen, so the rebreather’s primary tasks are to remove the carbon dioxide and replenish the life-sustaining oxygen.
This process begins in the scrubber unit, where a dry chemical removes the carbon dioxide from the breathing loop, and a series of sensors measures the remaining oxygen. In electronically controlled systems, these sensors signal a solenoid valve to add just enough pure oxygen to the mix to achieve the ideal partial pressure of oxygen (PO2) for the depth (see: “How Closed-Circuit Rebreathers Work”). In what are known as mass flow designs, the unit uses a calibrated orifice to inject oxygen and maintain a minimum PO2. The diver monitors a PO2 display and manually adds oxygen to the loop in order to reach a higher PO2.
A CCR adds only a small volume of oxygen to the system at a time, so a compact oxygen cylinder — usually 30 cu ft (850 L) — is all that is required for most dives. As a result, CCR divers plan their dives with their metabolic rate and PO2 preferences as the primary limitations on the depth and duration of a dive. A second cylinder holds a diluent gas, usually air for dives 150 feet (46 m)and shallower, though in advanced and deeper applications a properly trained diver may choose to use tri-mix. Diluent gas is added to the breathing loop during descent and during normal diving practices. The diluent bottle matches the size of the oxygen cylinder to provide a balanced, light (often less than 60 lbs or 23 kg), streamlined diving rig that provides hours of bottom time without the need for heavy double scuba tanks. Since the diver is breathing the ideal gas mixture at every depth, no-decompression limits can be substantially longer. And with virtually no exhaust bubbles, divers can better approach marine life. CCR Training
CCR training and diving practices are substantially different from open-circuit scuba. First, the diver has to learn to think in terms of partial pressures of gases in relation to depth, whereas open-circuit divers need only to stay shallower than the maximum operating depth (MOD) of the gas they are breathing. CCR divers also need to be especially careful of rapid descents or ascents as PO2 levels change rapidly as ambient pressure changes.
Buoyancy control is different with a CCR. When a diver inhales on conventional scuba, the additional air in his lungs causes the diver to become positively buoyant and exhaling will cause him to become negatively buoyant. CCR divers, however, maintain a fixed volume of gas between their lungs and the rebreather at all times and experience unchanging buoyancy.
Classroom training concentrates on advanced diving concepts including partial pressures, gas consumption, workloads, oxygen set points, decompression planning, scrubber materials, bailout procedures and recovery procedures, to name a few. Divers train on a specific CCR unit and must get to know the system intimately. Maintenance is a high priority. CCR divers need to disinfect, assemble, test components, check for oxygen sensor reliability and perform positive and negative pressure tests before each dive. To avoid potential problems or missed steps, wise CCR divers employ checklists to assemble units before use.
Initial training dives focus on a variety of diving drills unique to rebreathers, including bailout techniques and the proper response to low and high oxygen warnings, oxygen failure and total gas failure. It is also necessary to learn how to add gases manually and maintain the proper partial pressure of oxygen. Many CCR divers also carry a redundant bailout system. Therefore, additional time is spent on properly configuring the individual diver’s gear to aid in streamlining.
Breathing on a CCR is a different feeling compared to open-circuit scuba, and it takes a few dives to get used to. With conventional scuba, divers are used to the feeling of air being injected by the regulator. But with a CCR, it’s your own breathing cycle that moves the gas. At first, it feels as though there is an inadequate supply of air, but the feeling soon passes as the diver gains experience. The second feeling is one of trust. The computer consoles constantly give information about depth, time, no-decompression limits and, most importantly, the PO2 circulating in the breathing loop.
It takes a few days of open-water training to begin to master the skills, but the more you dive with a CCR, the easier it is to understand what is going on. Training dives, designed to demonstrate CCR capabilities and build trust in the unit, may be as long as two hours. All in all, a CCR course can take as long as one week, depending on location and travel schedule. The Payoff
After completing our initial training in a quarry, my buddy and I decided to test our skills in the St. Lawrence River on the wreck of the Keystorm. The wreck is more than 250 ft (76 m) long, intact and lying on its starboard side. Descending to the wreck required performing the necessary set-point changes on the computers. Then the fun began! It was almost unsettling how quiet the dive was and with no exhaust bubbles to dislodge sediment, visibility remained pristine as we made our way through the wreck.
Our second dive was to the wreck of the Gaskin. The dive plan called for a two-hour exploration with a maximum depth of 60 ft (18 m), though most of the dive would be to 50 ft (15 m) and shallower. Since we would be breathing at the optimum partial pressure of oxygen and moving into shallower depths as we went, we could enjoy a leisurely dive without incurring any decompression obligation. The beach entry point put us close to the ship, and as we approached in silence, we could hear a group of open-circuit divers on the wreck before it even came into view. We enjoyed a long, spectacular dive and surfaced surprisingly refreshed.
Diving a closed-circuit rebreather is not for every diver, nor is it for every diving situation. But it can be a fun experience and in the hands of a properly trained diver, a CCR system can be a powerful tool for exploring and enjoying the underwater world.
While closed-circuit rebreathers (CCRs) have long been a tool of military and professional divers, only in the past few decades have technological advances made them widely available to recreational divers. Today there are about a dozen models on the market to meet the needs of divers who want to experience longer, deeper dives.
However, diving with a CCR requires skills and dedication well beyond that of open-circuit scuba. These systems are sophisticated machines, capable of reliably delivering ideal gas mixtures throughout the range of a dive, but they require close supervision by the user. In the case of equipment failure or operator error, a diver can be served a life-threatening breathing gas. If it happens without warning, the risk of death is high. Sadly, a review of DAN’s fatality surveillance data shows rebreather fatalities have increased since 2000 and now account for about 6 percent of known diving deaths.
CCRs allow divers to push the limits of our collective experience and current knowledge. We do not yet have the data needed for an evidence-based risk/benefit analysis for CCR diving, but it is clear that divers who choose this technology can minimize their risk by dedicating sufficient time for training and by adhering to best diving practices, including diving with a buddy and having appropriate topside support.
— Petar J. Denoble, M.D., D.Sc.
DAN Senior Research Director
4 courses mashed together for an advanced technical related diving bonanza
Koh Tao, Thailand
Big Blue Tech celebrate the graudtion of Jennifer Brogan, Regine Petersen, Anthony Mure, Jamie Hyde from their TDI Nitrox, TDI Intro to Tech, SDI Limited Penetration Wreck Diver and SDI Deep Diver Specialties.
These courses were combined in to various diving activites over the course of 6 days to complete a higher level of training for the Divemaster Interns enrolled in a 2 month internship to become certified divemasters, dive leaders and Dive Cons.
The course began with theory and Intro to Tech course so they could complete the future training in a twinset with technical equipment configuration.
The course continued onto using custom mixes of 29% for the wreck dive and deeper depths to 36% for shallow skills and line work. The wreck penetration skills were completed on the “Trident” wreck located off the coast of Koh Tao near shark island which was purposely sank to provide an environment for overhead training.
This mash-up of diving courses is only available to our divemaster interns however these courses are offered individually on request.
More recreational divers are discovering the advantages of sidemount scuba cylinders.
Koh Tao, Thailand
Big Blue Tech Congratulates Graeme Scott for completing his SDI Sidemount Course on Koh Tao by Diverite Nomad Technical Instructor James Thornton-Allan conducted over 2 days on Koh Tao Island off the coast of Thailand.
Historically, sidemount diving was for extreme, technical divers who used the configuration to penetrate small sections of caves. But its adaptability and advantages have been discovered by divers of varied experience levels, and that, coupled with advances in equipment and greater availability of training, has made sidemount diving an increasingly common application. It’s not just for cave divers anymore.
Sidemount is a gear configuration in which a diver wears a tank on each side of his body instead of mounted on his back. Sidemount tanks lie parallel to the body, below the shoulders and along the hips. Since the tanks are not connected by an isolation manifold, as they are in a backmount configuration, the diver has two separate and redundant sources of gas and will breathe first from one tank and then the other, switching back and forth between two independent regulators throughout the dive. The clips on the bottom of the tanks are attached below the hip, and the top of the tank is secured with a bungee system, which allows the tanks to ride along the side.
The advantages of sidemount diving first resonated with advanced and technical divers who realized that wearing tanks on the side of the body created a lower profile in the water than traditional backmounted tanks, thereby allowing access to, and the exploration of, small spaces without disturbing the environment. Less silt equaled greater access. Wreck divers discovered they could push a tank ahead of them into a small hatchway by simply unclipping the bottom portion of the tank from the buttplate. Cave divers saw the same benefits when working their way through low, overhead passageways. Reef divers, too, implemented sidemount diving to improve the navigation of tight coral canyons while hopefully reducing unintentional coral contact.
But whether diving a wreck, cave or reef, every specialty recognized the safety benefits of sidemount diving. A sidemount configuration gives a diver easier access to tank valves in an emergency. Some divers carry sidemount “bailout bottles” specifically for this purpose. Sidemount rigs make it easier when divers need to swap out extra tanks staged along a tagline or the floor of a basin. The position of the tanks also gives the diver’s head greater range of motion for enhanced vision and comfort.
One final advantage for sidemount enthusiasts is simply the management of what can be a heavy load. Considering the average technical rig weighs approximately 130 lbs., it’s easy to see the appeal of a system that allows for the placement of tanks in the water ahead of the diver, allowing him to enter the water in nothing more than a basic harness system. The tanks then clip in, but with the weight burden significantly reduced through buoyancy. Of course, when the dive is done the process is easily reversed, allowing divers to exit the water with the same ease. Older divers and petite women are two dive demographics increasingly embracing sidemount diving for these very reasons.
Sidemount configurations are proving a good fit with the increasing popularity of rebreather diving. Because of the cluttered front presented by rebreather hardware, the sidemounted “bailout bottles” provide an unobtrusive way to carry an emergency air supply. The sidemount tanks also provide a ballast of sorts, creating a more streamlined profile and manageable center of gravity.
To Train Or Not To Train
Like all forms of specialized diving, divers should seek training to learn about sidemount diving. Experienced technical divers already accustomed to gas management and dealing with multiple cylinders and the rule of thirds will likely figure out how to sidemount with the help of a good workshop emphasizing the ergonomics of the system. Even then, it will likely take quite a few dives to balance the rig just right and to make the operation intuitive. Every diver must decide if these adjustments are a puzzle to solve on his own or a special skill set to hone with the help of an instructor.
Divers who are not technically trained yet want to get started in advanced diving with sidemount should take a structured course. Proper training will include removing a bottle underwater and swimming while pushing the tank in front of the body, donning tanks while floating at the surface, air sharing, gas management and deploying a surface marker. Working with an instructor will help the diver configure the finer nuances of the rig, set up the tanks properly and make sure the trim is correct in-water. Courses are typically run over two days.
Divers should choose an instructor who is familiar with their intended dive environment. There are differences between sidemounting from a boat or a cave or a wreck, and the best instruction is scenario-specific. Divers come in a variety of shapes and sizes with a variety of needs; ensure your instructor is knowledgeable on the various sidemount options and can teach you what you need to know.
How To Choose
There are dozens of sidemount rigs on the market; the diversity can be bewildering. As with all diving equipment, it’s important to define your own needs and fit your unique body type. What works for one diver won’t necessarily work for another, so do some homework before buying.
To find the rig that works best, a potential sidemount diver needs to do a thorough assessment of his dive environment and understand how personal body type and buoyancy characteristics affect a rig. Don’t try to squeeze custom needs into a “one-size-fits-most” configuration. What are your rig lift needs? Do you need your rig to be easily adaptable, or do you need one highly specialized for a specific environment? A cold-water diver may wear heavy steel tanks and need a rig designed for that environment, including a wing with enough lift for the tanks, materials that are cold-water friendly and adjustment points that can be handled with thick gloves. Cave divers in Florida may need something entirely different, and deep wreck divers off New Jersey may require something else again.
Pay attention to safety features: Do they meet the needs of your dive environment? If you plan to sidemount from a boat, you should make sure your rig is designed with the proper safety clips in case you have to enter or exit the water with the tanks attached to your harness. (This can happen when a boat encounters rough seas and transporting the tanks one at a time, unattached to the diver, can be difficult or dangerous. Rather than stress or snap the bungee system, the diver uses the clip located on the neck of the tank to clip into something more robust, like a harness D-ring.)
Divers planning to squeeze into restricted spaces with protrusions need to pay attention to the placement of the inflation hose and bungee system, along with other potential snag points. A buttplate tucked beneath a wing would be a potential problem, and the inflation hose should have a protective sleeve and a low profile. A continuous, one-piece bungee system is not necessarily considered the safest alternative; the prevailing trend these days is two separate bungees. That way if one bungee is sheared, you won’t lose control of both tanks. Keep in mind that safety and redundancy in advanced diving is critical.
Both recreational and technical certification agencies now offer sidemount training, making it easier to find an instructor. More and more sidemount divers are seen on boats and at dive sites; as part of your due diligence, ask their opinion on why they choose to sidemount and what safety features are critical to the dive environment. There’s a wealth of information eagerly disseminated amongst those early adapters of the equipment. For while it’s not necessarily mainstream just yet, sidemounting has definitely come out of the cave and into the light of day.
Outside of training and service duty, a common ritual within the armed forces if the trading of ‘dits’ over a ‘wet’ or two. That’s swapping of anecdotes over drinks to you and I, but with the kind of intrigue and bravado that separates the men from the boys.
Saturday afternoon, The Big Scuba Show, 19-20 February, will be your chance to meet the Marines at The Big Scuba Show
If you fancy sharing a tale with the Royal Marine Commandos, come on down to the show and call in to stand 440.
The Big Scuba Show and DIVE Magazine are inviting you to prove you have The Commando Spirit.
DIVE is looking for three brave divers to take on the challenge. DIVE will pay for three diver’s entry fees for the challenge (£300 each) and Monty Halls will act as their personal mentor. The three fundraisers will in turn each need to raise £10,000 for Commando Spirit and The Royal Marines Charitable Trust Fund.
DIVE will encourage the diving community to support their fundraising efforts.
Entries for this competition closed on 8th January 2011. We are now in the process in judging the entries and selecting the 3 deemed brave enough to escape the dunker.
COMMANDO SPIRIT – THE ROYAL MARINES CHARITABLE TRUST FUND
The Big Scuba Show has chosen its official charity for the next three years and is supporting the Commando Spirit Appeal on behalf of the Royal Marines Charitable Trust Fund. The Commando Spirit Series is staging a series of challenges over the next three years with the aim of raising £1million for the Royal Marines Charitable Trust Fund, which helps Royal Marines who are wounded or injured and supports those returning from operations and their families. Sadly but importantly the RMCTF also provides grants to those whose loved ones die in service. Quite simply, the RMCTF will help when others cannot.
The Big Scuba Show intends to work closely with the team behind Commando Spirit and the Royal Marines Charitable Trust Fund to ensure their valuable cause is recognized throughout the diving world.
This year Commando Spirit is offering fundraisers the chance to see if they have what it takes to react like a Royal Marine Commando. During training, Marines face the Dunker – a terrifyingly realistic simulation of a helicopter crash at sea, from which they must escape. Fundraisers will get to experience the Dunker for themselves and test their mettle against this ultimate challenge.
“I vividly recall my first experience in the Dunker – my racing heartbeat and clammy palms as the waters rose around me,” said ex-Marine Monty Halls. “Although 100 per cent safe, it is nonetheless a life-enhancing experience for those who take part. You’ll turn up trembling and swagger out beaming, ready to take on the world.’
“Those taking part will be pushed to their limit but will feel an immense sense of achievement – and they will also get a taste of what our Royal Marines go through on a daily basis, whether in training or on operations.” Maj Gen John Rose CB – Representative Colonel Commandant of the Royal Marines and Patron of the Commando Spirit Appeal
‘Show Your Courage For Those Who Risk Their All’
THE JUDGES
Brigadier Simon P Hill OBE is Chairman of the Royal Marines Charitable Trust Fund’s fundraising campaign board. Brigadier Hill served in the Royal Marines for 34 years and has therefore completed the Dunker training. Brigadier Hill was Chief of Staff at Royal Marines Headquarters for two years, before being appointed Colonel Commandant and President of the Royal Marines Association in 2002. Brigadier Hill is also a Trustee of the Royal Navy and Royal Marines Charity. He commanded the Comacchio Group RM at Arbroath for which he was awarded his OBE.
Sally-Anne Hunter:
Founder and director of Commando Spirit, Sally-Anne Hunter is a BSAC diver and a former Trustee of Coral Cay Conservation, holding diving close to her heart. A trained barrister and Fellow of the Institute of Fundraising and the Royal Geographical Society, her passion for all things challenging and charitable is evident throughout her career which has seen her direct events to raise funds for breast cancer charities through the Booby Birds and Breakthrough Women’s Challenge, for Operation Raleigh through The Power Challenge and now for the Royal Marines Charitable Trust Fund through The Commando Spirit Series, allowing people to test their mettle against some of the more formidable aspects of Royal Marines training.
Monty Halls:
TV presenter and former Royal Marine Monty Halls is a writer, explorer, television presenter and public speaker. A former Royal Marines officer who worked for Nelson Mandela on the peace process in South Africa, he left the services in 1996 to pursue a career in leading expeditions. Having achieved a First Class Honours degree in marine biology, over the next decade he circumnavigated the globe four times on various projects, leading multi-national teams in some of the most demanding environments on earth.
Mark Ormrod:
A former Royal Marine, lost both legs and an arm in an explosion while serving in Afghanistan on Christmas Eve, 2007. Since then Mark has fought back from his injuries to launch a fundraising drive to help other soldiers, sailors and airmen whose lives are torn apart on the battlefield; to write a book, Man Down, about his experiences and to marry. Mark exhibits true Commando Spirit.
Graeme Gourlay: Managing director of The Big Scuba Show. A former news editor of the Sunday Times, Graeme Gourlay developed a passion for scuba diving and set up his own publishing company in 1995. Circle Publishing now has a wide portfolio of titles including among others the UK’s market leading scuba diving magazine DIVE, the Royal Geographical Society’s Geographical magazine and R-Travel for the Responsible Travel awards. Graeme has recently launched The Big Scuba Show at which the Royal Marines Charitable Trust Fund is the official charity.
For more information on Commando Spirit and The Royal Marines Charitable Trust Fund please visit www.commandospirit.com or www.rmctf.org.uk
The Big Scuba Show and DIVE Magazine are inviting you to enter and prove you have The Commando Spirit. A specially selected judging panel from Commando Spirit, the Royal Marines, Dive Magazine and The Big Scuba Show will then choose the three lucky participants to be announced live at The Big Scuba Show, 19-20 February.DIVE is looking for three brave divers to take on the challenge. DIVE will pay for three diver’s entry fees for the challenge (£300 each) and Monty Halls will act as their personal mentor.
With all the chaos in Cairo you might be looking for a new place for your club or group to go diving then Big Blue Diving in Koh Tao Thailand is inviting you to come here and join us with our new 7 day, 7 night diving package for certified and experienced divers.
We’re offering unlimited fun diving with all the trimmings in our resort. Big Blue Diving is a BSAC Center of Excellence, SSI Platinum Facility, PADI Dive Center, TDI 5 star IDC Center, SDI Center, BSAC Technical Center and award winning ecological center for green and eco initiatives.
Big Blue Diving have 3 large boats departing 3 times daily along with a lively bar, restaurant and hotel or bungalow accommodation to suite any style.
We’re located directly on the beach, that means there is no distance to walk to the water.
The promotion is as follows.
7 Days, 7 Nights Diving Package
- Unlimited Diving (pinnacles, wrecks, caves, coral)
- Unlimited Boat or Shore Diving
- 10% off all equipment purchases
- Free T-shirt and water bottle cooler
- Night Dives
- Full day Trip to Sail Rock
- All equipment Rental
- Airconditioned Hotel Accommodation, satellite TV, Fridge, Balcony with sea view, Hot Water
- Breakfast Daily
- Wifi
- Taxi service around the island 30,000 Baht Save 3000 Baht with your own equipment (DIN or INT tanks available)
BSAC Members get free Nitrox!
14 Days, 14 Nights Diving Package
- Unlimited Diving (pinnacles, wrecks, caves, coral)
- Unlimited Boat or Shore Diving
- 10% off all equipment purchases
- Free T-shirt and water bottle cooler
- Night Dives
- Full day Trip to Sail Rock
- All equipment Rental
- Airconditioned Hotel Accommodation, satellite TV, Fridge, Balcony with sea view, Hot Water
- Breakfast Daily
- Wifi
- Taxi service around the island 55,000 Baht
Save 6000 Baht with your own equipment (DIN or INT tanks available)
BSAC Members get free Nitrox!
Big Blue Tech celebrates the graduation of Graeme Scott from his TDI Advanced Nitrox and Decompression Procedures “combined” course conducted over 5 days on Koh Tao Island off the coast of Thailand by TDI Instructor Ash Dunn
Graeme visited us last year to start his technical training but found us on the road, as a second choice he completed a introductory technical course with another company. Still eager to complete his TDI training Graeme has returned for a month of training and diving with us here in the sunny tropics of Koh Tao.
Typically Big Blue Tech don’t do the combined course as there’s too much information and skill mastering for such a short period of time. Graeme already has some experience in the technical diving gear from his previous certification so he progressed smoothly through the combined course.
Graeme will return to some diving today to master his backwards fining and practice some more skills while he awaits the start of his Sidemount and Advanced Wreck course in a few days.
The focus of these combined courses is to train students to be successful in technical diving. These classes are taught as if they are a small piece to a much larger picture, not as entry level technical diving. These courses build the foundation for sound technical diving. What you will learn will be utilized in higher level trimix courses. This is not a course to learn or re-learn fundamental diving skills. Students will be held to a higher level of performance not found in many technical diving courses.
Students are taught and evaluated, not only on skill proficiency, but control, leadership, situational awareness, teamwork, and judgement. Successful students will have a finesse that few divers have. You will finish this class with the confidence, competence, and comfort to be able to complete dives at this level of training prior to receiving a c-card.
Expect to dive every day with lectures in the afternoon and evening for each day. The majority of dives will be conducted in shallow water for critical skill evaluation. However, each day will get deeper as the class progresses. The final day is reserved for experience dives that will be at depth with a real decompression obligation.
Course content will include, but not limited to: enriched air Nitrox usage, decompression mixtures, diving physics & physiology, dive tables, advanced decompression theory, oxygen exposure/management, team diving procedures, and contingency planning.
Keeping up with line markers is always an issue. Over the years sliding them on a piece of surgical tubing or bungee has been the preferred storage. I see some cave divers doing a bungee on the primary light handmount. I liked the idea, but I had a few storage and deployment problems so I modified it by using a 6-inch piece of 3/16 bungee and stretching it through the adjustment bracket on the Goodman handle. I store the markers on the outside of the handmount with the knot keeping them in place.
I find this quick and easy to deploy. I can even keep directional markers on one side and non directional on the other side.
Big Blue BSAC Diving Centre is the only BSAC Centre for Excellence in ASIA and is also a BSAC Technical Centre.
Big Blue Diving was, founded in 1991, and was one of the first dive shops to open in the Gulf of Thailand. Offering diving courses from beginner to Instructor level, fun diving for divers of all levels, technical diving, modern equipment and facilities, staffed by experienced dive professionals, Big Blue resorts are here to meet all your needs.
The move to create a separate BSAC Academy is to help the staff focus on the BSAC customers, divers and instructors around the world.
Big Blue Diving has been an active BSAC centre since 2009 but only became a centre of excellence in 2010 and now has their own website and dedicated BSAC instructors to welcome new divers.
Big Blue BSAC Diving Centre will be working with different clubs to provide charter trips around south east asia, sponsor education events and promote ecological awareness with both wreck preservation and environmental assessments.
With research grants and international funding Big Blue BSAC will be looking to the community to help us complete the tasks of 2011 along with our regularly scheduled training programs.
Big Blue Tech – Technical Diving Thailand – Celebrates the graduation of Buddhi De Silva Wickramanayake from his TDI Trimix Diver Course and Rodney Gibbs completes his TDI Trimix Instructor Course with TDI Trimix Range Instructor Trainer Ben Reymenants during a week long scuba diving workshop and deep technical diving session off the coast of Thailand on Koh Tao Island.
The term “mixed-gas diving” refers to any activity in which the diver breathes a mixture other than air or nitrox. The main incentive to dive with “non-air” gas mixtures is to avoid nitrogen narcosis. Mixed-gas diving can also be beneficial in improving decompression and avoiding oxygen toxicity. Mixed-gas diving operations require detailed planning, sophisticated equipment and, at times, extensive support personnel and facilities. The fact that such dives are often conducted at great depths and for extended periods of time increases the risks associated with them. It is extremely important for the breathing mixture to be properly identified, because breathing the wrong mix can lead to a fatal accident.
One type of mixed gas diving involves the use of heliox. This (helium 79% and oxygen 21%) mixture is often used for very deep diving. Unlike nitrogen, helium is not known to have an intoxicating effect at any depth; it has a lower density than nitrogen, making it easier to breathe; and in cases of extended submersion, it improves decompression. Still, heliox has its drawbacks. It is expensive, has a limited availability, and its thermal conductivity is six times greater than that of nitrogen. This means that a diver breathing heliox will lose body heat six times faster than someone breathing compressed air or nitrox, making them susceptible to hypothermia. To prevent this, divers often wear special suits filled with hot water that is pumped down from the surface. Heating the heliox before the diver inhales it is another strategy used to combat hypothermia. Either of these procedures require specialized equipment and highly trained personnel.
Big Blue Tech is a supporting member of The SSS Recompression Chamber Network here in Thailand. We pay an annual fee to the organization for support during diving related emergencies. This support gives us the opportunity to have their staff come to our school and train our Thai staff in how to handle diving related emergencies and how to provide oxygen to help divers with suspected decompression sickness to delay the onset on symptoms during transport to the chamber in the neighboring island Koh Samui.
The SSS Network / Samui Chamber Facility supports the diving community by offering numerous free services including: medical advice, the latest dive safety tips, Decompression Illness Seminars and Chamber Orientations. They also offer ongoing training and education to the Dive Operators and Health Care Providers throughout Thailand.
For the individual Thai boat captains and boat staff they are only too happy to spend time sharing the importance of oxygen for diving injuries, the use of their on-board equipment, and the guidelines for oxygen provision. The regularly teach Oxygen and first aid courses, and for those wanting to expand their knowledge of diving medicine they also offer Recompression Chamber Tender/Operator “TOP” courses.
The evening seminar was attended by Big Blue Tech captain “P-Dam” , boat boy “Zaw”, shop staff “Lee” and tai driver “Tia”. This creates a continuous line of care from the boat to the dinghy through the shop and then on to the taxi to the main pier for evacuation. This also gives our local staff a better understanding of the environment they’re working in.
Big Blue Tech – Technical Diving Thailand – Celebrates the graduation of Buddhi De Silva Wickramanayake from his TDI Extended Range Diver Course and Rodney Gibbs completes his TDI Extended Range Instructor Course with TDI Extended Range Instructor Trainer Ben Reymenants during a week long scuba diving workshop and deep technical diving session off the coast of Thailand on Koh Tao Island.
During diver training, dive students are normally drilled to avoid diving beyond 130 feet / 39 meters. However this depth limit recommended by most of the training agencies is not forged in stone. Historically, it appears that it probably emerged from the U.S. Navy, possibly as a result of equipment limitations at that time, and the work restrictions imposed by the relatively short no-stop times available at greater depths.
An increasing number of divers dive beyond the 130-foot limit, some routinely and others occasionally. The advent of dive computers has negated much of the decompression penalty and dive restrictions previously associated with deep diving, and has no doubt encouraged the current trend. In addition, the increased availability of a variety of gas mixtures has enabled more divers to venture deeper and deeper.
Deep diving demands vast amounts of knowledge, experience and discipline, as well as appropriate preparation and equipment, since deep diving is fraught with potential hazards.
There appear to be some inescapable realities of deep diving. These include:
the increased potential for certain problems to occur;
if a problem does occur, the consequences are often more serious; and
the fact that the physiological effects of deep diving are still largely unknown.
An old friend of mine used to teach diving at a tropical resort. The instructors routinely dived on air to depths approaching 300 ft (90m) and beyond on their days off. During such a dive, one instructor became unconscious at about 200 ft (60m) without obvious warning. He fell away and out of reach of the others before anyone could get it together to do anything. His body was never recovered.
Elsewhere, another diver diving at just over 165 ft (50m) on air on a wreck was seen to become unconscious and to convulse. Luckily his buddies managed to rescue and resuscitate him.
These are not isolated stories, and there are many similar reports involving deep air dives and mixed gas dives.
Unconsciousness underwater is often associated with deep diving accident reports. It usually results in drowning. A number of conditions can cause a diver to lose consciousness underwater. Such conditions include, but are not confined to:
high blood carbon dioxide levels (hypercapnia);
oxygen toxicity;
nitrogen narcosis; and
decompression illness;
All of which are exacerbated by depth. Blackout underwater may not be due to a single cause, but may result from a combination of physiological or physical factors.
Nitrogen narcosis can become a very serious adversary on deep air dives. Although we can acclimatize ourselves to the affects of narcosis to some extent by regular exposure to depth, it can still sneak up and very quickly overcome us when we don’t expect it. Although conventional wisdom states that the narcosis appears on arrival at a particular depth and usually does not worsen with continued exposure at that particular depth, many divers are aware that it can quickly be precipitated by exertion or stress at depth, without further descent.
Divers who have had to quickly deal with a problem at 200 ft (60m) on air realize the extreme difficulty of reacting rapidly and appropriately. Sometimes the mind-numbing effects of narcosis can strike suddenly and make appropriate reactions almost impossible. Extremely high levels of stress can be precipitated instantaneously and, unless controlled, panic and injury are likely results. Narcosis may be the direct cause of unconsciousness in a diver at depths somewhere in excess of 200 ft. Narcosis can be reduced by using certain gas mixtures. However, this involves the appropriate equipment, preparation, training and care since new potential hazards are introduced.
Carbon dioxide acts as a respiratory stimulant and can cause depression of the central nervous system (CNS). The effect depends on the level of carbon dioxide in the blood. Deep diving produces elevated blood carbon dioxide levels for several reasons, which include:
the resistance to breathing caused by breathing denser gas through a regulator and against a higher ambient pressure;
reduced ventilation efficiency due to the denser breathing gas; and
reduced transport, and, hence, elimination of carbon dioxide.
Hypercapnia increases narcosis and the likelihood of CNS oxygen toxicity. In addition, it may increase heat loss, alter heart rhythm and predispose to decompression illness. If the carbon dioxide level gets too high, and it can on deep scuba dives — especially if a diver is very anxious and / or exerting him/herself — the diver may go unconscious without warning. Certain divers are more susceptible to severe hypercapnia for a variety of reasons and are therefore more at risk.
When divers breathe oxygen at partial pressures greater than about 1.5 atmospheres (ata), it may rapidly exert a toxic effect on the brain. A diver breathing air at a depth of around 200 ft is exposed to an oxygen partial pressure of 1.5 ata. CNS toxicity is a limiting factor and a very real danger in deep diving since it can cause a diver to convulse and/or become unconscious with little or no warning. The likelihood of CNS oxygen toxicity increases with exposure time, cold, exertion and hypercapnia, and the depth and time of onset can vary greatly between individuals and from dive to dive.
The high nitrogen load accumulated by the “fast” and “medium” body tissues during a deep air dive can cause substantial bubble formation during or after ascent unless the decompression is properly controlled and conducted. Some of these bubbles may form in or enter the arterial circulation and cause neurological problems. This mechanism may be responsible for some underwater blackouts during ascents from deep dives.
Various data indicate that deeper diving is associated with a substantially increased risk of decompression illness. This risk appears to increase at depths beyond about 80 ft (24m). In addition, using a dive computer to guide decompression from deep air dives appears to increase the risk further due to the greater dive times allowed and the increased unreliability of the algorithms at depth. More and more divers have adopted the use of various gas mixtures in the belief that it will reduce the risk of decompression illness. However, recompression centers still treat a significant number of these divers.
Certain studies suggest that microbubbles are often present after dives, particularly deep dives, especially if ascent has not been appropriately executed but even after what is generally considered to be a safe ascent. Some hyperbaric specialists fear that microbubbles, although asymptomatic, may cause cumulative neurological damage in divers. However, to date, the evidence does not appear to be consistent.
Unless adequately prepared for, deep diving carries a higher likelihood of an air supply emergency. Increased ambient pressure means increased air consumption. In addition, narcosis may hinder a diver’s ability to properly monitor and manage the air supply. Despite the improvements and superior performance of much of the modern diving equipment, malfunctions do occur. The deep divers who value their hides ensure that they have adequate backups of various essential pieces of equipment, including an independent and adequate air supply.
Buoyancy compensation can sometimes become a critical factor on deep dives, especially in cold water where greater insulation is required. Unless compression of the exposure suit is adequately compensated for by BC or dry suit inflation, a diver may become very negatively buoyant at depth.
Wreck divers may sometimes prefer to be negatively buoyant, but problems can develop if the air supply is low and the diver needs to ascend fairly quickly.
Various experiments have demonstrated that, at low cylinder pressures, it is sometimes impossible to inflate a BC (or dry suit) at depths approaching 130 ft, especially while breathing simultaneously from the regulator. This problem would be magnified at greater depths. At times, a negatively buoyant diver who is low on air may find it difficult, or even impossible, to ascend without ditching their weight belt. If the weight belt is ditched, it is unlikely the diver will make it to the decompression line to get some extra air and perform any necessary stops.
Some divers routinely dive to depths in excess of 165 feet/50 meters on air, although over recent years gas mixtures such as heliox and trimix have become far more commonly used for very deep diving as they are less narcotic. These divers are often, but not always, conversant with the substantial risks and demands of these dives and choose to push the limits for their own reasons. Such divers are usually well equipped and well prepared for the dives. Most usually manage to get away with diving to these depths with no apparent problems, others do not. Some of the unfortunate ones are left with permanent disability; others die.
On the other hand, there is the “occasional” deep diver. These divers are generally less experienced than regular deep divers, are on a dive trip with a group, and are drawn into diving deeper than they normally do because of the more relaxed holiday atmosphere and because “everyone’s doing it.” Such divers are often not sufficiently trained, mentally prepared and appropriately equipped to deal with a problem should it occur on a deep dive.
It becomes obvious that there is no safe depth limit that applies to all divers all of the time. A diver’s ability to cope with depth depends on a number of highly variable factors. The depth of the onset of the effects of the exotic cocktail of elevated pressures of nitrogen, carbon dioxide and oxygen, coupled with the sensory deprivation and stress associated with diving, are not always predictable. A dive to 80 feet in cold, dirty water can be far more hazardous than a dive to twice the depth in warm, clear waters. Factors such as visibility, water temperature and diver experience and preparedness greatly affect a diver’s comfort and safety, rather than depth alone.
Divers in remote locations must also be aware of the complications associated with medical evacuation. These can include significant delays in retrieval due to lack of current availability of an aircraft and and/or medical team, the distances involved, as well as the accessibility of some airstrips in darkness or adverse weather conditions. Such delays can impact the amount and the effectiveness of the subsequent recompression treatment, and the likelihood of residual injury.
In addition, once a diver has been evacuated and/or treated for DCI, they will be advised to avoid air travel or driving to altitude for between three days and six weeks post treatment to avoid recurrence of symptoms. This can certainly impinge upon the diver’s travel and work commitments.
As with many things in life, one must balance the risks against the benefits and make a decision. However, it is essential to have a real understanding and appreciation of the risks.
Big Blue Tech had a day off yesterday and in true diving spirit we boarded the recreational diving boat for a day of sun, fun and relaxation on the open seas during a full day trip to Sail Rock dive site off the coast of Thailand between Koh Tao and Koh Phangan.
The day started at 6:30 with the loading of a Closed Circuit Rebreather (ccr) that Ash would be diving on and the cylinders for the sidemount for James and Ian and the single tank for Helen, who despite her best attempts was short strawed into teaching a deep specialty at the last minute.
The Boat departed shortly there after and we were rolling through the 2 and half hour journey to the dive site. Time flew by with equipment setup, breakfast and briefings. The tech crew just went to sleep (day off) but were woken by the sound of the passengers being divided from the people who had an iron constitution an those that didn’t. The peaceful silence of the waves crashing off the bow was violently interrupted by an orchestra of sea sickness from the floor below. Although initially only one person, the effect was cascading causing borderline divers to loose it.
Arriving at Sail Rock, which is a pinnacle above the sea, we were sheltered from the waves and current so everyone could relax. The diving in Sail Rock is the best in the region, without question the best site on the east coast. It also has a really cool vertical cave, there’s also lots of marine life, you can email info@bigblueconservation.com if you want to know what kinds.
Two dives done, lunch served and we headed off to “Southwest Pinnacle” located south west of Koh Tao, obviously. At south west everyone jumped in and then discovered there was an incredible current. Ash and James realized the dive would be difficult so they stood on the deck shouting motivational slogans at Ian (the junior staff) to kick harder and get to the buoy line. In hindsight Ian should of just given up but his attempt to kick with 4 cylinders in sidemount on the surface in a ripping current was just to funny to give up. After 10 minutes he reached the bow, dropped down 10m, got pulled off the line, spent another 10 minutes and 70bar of air getting back to line to surface with a look of total and utter exhaustion on his face.
So with that dive scuttled-ed we headed to “White Rock” named by an Italian (there’s also red and green rock) where everyone enjoyed a third and final dive, except Ian who was asleep from his ripping current episode.
This day was key for us Tekkies as we’re constantly teaching and working that we never get the chance to go out and have some fun.
Big Blue are running weekly full day trips to sail rock, perfect for technical diving, feel free to join us next time.
