Thailand – Australia – United Kingdom

Side Mount Diving courses come to Thailand

by James Thornton-Allan
Koh Tao, Thailand

Cave dwellers among you will be familiar with the concept of dangling your cylinders from your hips during subterranean activities. In this environment it has been used for some time; the trend started in Europe in the 1960s and then moved across to the US in the 1970s. It always used to be an additional skill, something that was taught after competence with back-mounted twin sets had been established. However, a few years ago, it became acceptable practice within the cave-diving fraternity to just use side-mounts without the need to dive twins.

Since that time side-mount diving has increased in popularity, not only among cave divers but also among some of us with more terrestrial habits, both for technical and recreational diving. This increase in popularity is worldwide and is due to some extent to the development of a SDI Distinctive Training course. Now this program has been introduced at Big Blue Tech in Thailand as the authors of the course.

To qualify as a SDI Side-mount Diver you need to attend a two-day program that includes two dives using side-mounted cylinders. The minimum prerequisites for attending the program are  Advanced Open Water and you have to be 18 years of age.

For the recreational, non-decompressing diver this really is a great way to dive. You can obviously choose what size of cylinders you wish to dive with, but whatever your choice, safety is increased by having additional gas and bail-out options – something that many recreational divers attempt to provide with the application of the three-litre pony system. However, while it’s a great way of diving within normal recreational limitations, there is a huge plus with this program for those divers who wish to extend their diving beyond these limits. The SDI side-mount course has been endorsed by the Technical Diving International organization, which means that side-mounts can be used on all the programs in the Tec range.

So why might you be persuaded to give it a go? Well, the system has many advantages: First on the list would have to be safety. Diving with a side-mount system means that you have two completely separate life-support systems, so in the event of a failure on one you always have an adequate back-up even if you lose sight of your buddy during the dive.

Second on the list would probably be buoyancy control. Horseshoe wings and twinsets can take a bit of getting used to. Using the side-mount system, buoyancy and trim control is, quite frankly, a doddle and you will be looking good in no time. If you struggle with buoyancy then this program is definitely for you.
Another significant advantage is that there is no requirement to be a contortionist. Shut down drills can be difficult with twins and many times students on my courses have struggled with this element of the program. Divers often opt for slobknobs or inverted cylinders in order to make life easier. With side-mounted cylinders it’s a breeze. You can see the valves so if you do get a leak, simply look down, see which one it is and close it off.

If you struggle with the weight of twins on your back then you will appreciate side-mounts and the ‘twinset stoop’ will be a thing of the past. With side-mounts you can fit your cylinders in the water if you prefer, and getting kitted up is much less of a struggle. If you have ever tried getting your twin set on in a rocking RIB you will know what I am talking about! Oh, and don’t forget the skipper – he will love you for not having to haul your twin set over the side when you get back into the boat.

Another consideration is overseas technical diving. If you hire twin sets overseas then this system can save you money, especially in those resorts that allow you to have as many tanks as you want. On a recent liveaboard trip the cost of hiring twin sets was £80 for the week. The cost of two single cylinders was significantly less.

Finally, for those of you with a penchant for crawling through small spaces and wreck penetration, side-mounts offer you improved streamlining. The top of your profile is your head, not your manifold, and if you want to increase your streamlined profile even further you can even unclip the rear of your cylinders and hold them in front of you.

There are a few equipment changes you will need to make in order to use side-mounts. It requires a harness and wing with rails at the rear, but the good news is that the benefits of side-mount diving have been recognized and there are a number of manufacturers offering harnesses and wings specifically designed for side-mount. The new Hollis system with a 25kg lift capacity is the latest on the market and it can even be used for traditional back-mounted twins and single tanks. Alternatively, if you want to adapt your existing wing and harness system you can add a butt plate with rails to the backplate, so you don’t necessarily have to spend a fortune. The rest of the gear you need for side-mount diving will probably find you have already, just in a different configuration.

As a trimix instructor with many years of twin set experience, I was as sceptical as probably many of you are when I first looked at the side-mount system. Surely the extra gauge on the second cylinder would be an additional failure point; how would I possibly manage without the extra gas that the manifold offered me? The fact is that for every question I raised there were solutions. I think the only disadvantage that I couldn’t offer a solution to was the need to look at two gauges rather than one.

So why shouldn’t you give it a go? I can’t think of a good reason apart from the fact that we are a pretty traditional bunch. We like our Apeks valves and our Dive Rite wings and very often we don’t give new opportunities a chance simply because we have always done something else. “I must have cylinders on my back because I always have!” I admit, I thought the same initially.

When you actually look back over the years there is very little in the diving industry that has been totally revolutionary. Diving simply evolves over time. Fundamentally, I am diving with equipment that has not changed that much to the gear I used when I started diving 12 years ago. Of course, there have been exceptions over the years; the BCD, nitrox as a recreational diving gas, the affordable closed-circuit rebreather, the diving computer. All of these revolutionary changes took time to gain acceptance. While side-mount diving isn’t new by any stretch of the imagination, its application by mere mortals for recreational and technical diving in open water is revolutionary and, similarly, it will take time to become an accepted practice.

There is a possibility that side-mount diving might be just too different for many divers. It is a different method of kit configuration and a different method of gas management. Old habits definitely die hard in  diving, but the best I can do is to encourage you to give it a go. It offers some significant advantages and works well for any level of diving, both recreational and technical. It is growing in popularity and many believe it could, potentially, overtake twin set diving. So why not try something new. Go on, have a bit on the side for a change.

You can view the outlines of this course below



3 responses

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  2. Hi Jamie,

    This is great! I may drive down from Pattaya to learn sidemounts for recreational diving. I have found that tight penetration in wrecks is difficult with back-mounted tanks. Feel free to email me.


    August 15, 2010 at 3:21 pm

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