Last week I headed down to Tek camp at Vobster Quay with Leo from Ocean Leisure. We had only one thing on our minds: Sidemount. Yes I realise that sounds wrong, but let’s be honest you can add that to the list of diving terms that must be spoken cautiously out of context: Wreck penetration, blown O-rings, lubed wrist seals, pee valves and ball-gags all spring to mind (perhaps not the last one).
Anyway Sidemount is the latest trend to take the dive industry by storm and I’d been eager to have a go and find out what all the fuss was about. Sidemount is, exactly as the name suggests, mounting twin cylinders to the sides of your harness instead of on your back. If you’re diving recreationally you can take a couple of smaller ones, twin 7ls are very nice, and if you’re diving technically larger ones like twin ali 80s or 12l steels work well.
The principle of sidemounting cylinders is born out of the cave diving community where not having cylinders on your back enables you to squeeze through even smaller holes into caverns where you can get lost and die. Now those who know me will probably have heard my opinion on the fetishistic treatment of cave diving techniques by divers who don’t go into caves but you can’t knock something until you’ve tried it (another utterly asinine cliché, murder anyone?) so I was up for giving it a go.
Leo and I were looked after by the lovely chaps at Apeks/Aqualung who are also the distributors for Whites drysuits. It was lots of fun to rock up wearing my top of the range bullet skin with silicone lock seals but not quite as fun seeing the guy from Bare drysuits there whom I hadn’t told we were now a Whites dealer. Awkward.
Dean Martin (not that one) from Apeks helped us get geared up. The first thing to notice about sidemount harnesses is that they contain a lot of bungee which is a good thing, as all divers know the more bungee present the better, and the harness fits you much more snugly than most BCDs or other harnesses. The inflator hose comes across your chest and is held in place so that the wing inflator sits right next to your drysuit inflator. This makes it very easy to find but also means you can’t use it to vent air so you have to use the kidney dump on the wing to do this.
The tanks are then clipped onto the harness on a D ring at the waist but then instead of being clipped to a D ring on the shoulder of the harness they are looped into the bungee. this keeps them nice and snug next to you but also means that they can be moved around and manipulated if you need access to the valves.
We were using Apeks new sidemount regulator set: The right hand regulator feeds the wing inflator and has a 2m hose with a 2nd stage, the left hand reg feeds the drysuit with a really neat short hose and also has a shorter hose with a necklaced 2nd stage. Tec divers will find this arrangement pretty familiar. The setup was very tidy and routed in a very natural way. The principle is that you breathe equally from each reg, Dean told us he usually breathes about 40 bar from each reg.
The advantage of all this get up is that you end up with 2 completely independent cylinders that you can access very easily. Therefore shutdowns become a cinch in the event of a regulator free flow and should you have a catastrophic gas loss you know that the air in the other cylinder is completely safe.
So once we were all trussed up we headed over to the water and jumped in. Pretty much the first thing I noticed was how if you’re a diver who’s used to diving in a twinset, this isn’t going to faze you too much. However it was definitely noticeable how easy it was to get into a perfect horizontal trim, the cylinders at your side act like balancing weights almost forcing you into the correct position, no instability or roll from a single tank or the occasional sense of top heaviness from a twinset.
We headed off for our dive, both Leo and I were using the new Finnlight torches, which were 1400 lumens and were very nice and compact with a couple of power settings. There was a comedy moment when Dean fired up the video light on his camera housing, a 10,000 lumen torch (yes 10,000 lumens) which resembled an ammunition clip for a plasma rifle. This illuminated the whole of Vobster Quay and meant that anytime you glanced in his direction I was reminded of the scene at the end of Close Encounters when the doors of the spaceship open.
Being completely unused to breathing from independent cylinders I certainly didn’t find switching every 40 bar to be that intuitive but that’s really just a practice thing. I also enjoyed wriggling through some holes around the crushing works where having no tanks on your back means you don’t get that slightly brown drysuit moment when the tank makes a loud ‘bong’ noise as it collides with whatever’s above you.
So in conclusion what’s the verdict? Do I think that everyone should go out and burn their BCDs and twinsets and only ever dive sidemount ever again? Of course not, but I do think that sidemount is an intriguing extra option. There’s no doubt that it feels very nice in the water and for anyone who struggles with horizontal trim I think they would find this a very nice way to dive. However from a recreational perspective you do have the added complication of remembering to breathe from 2 separate tanks. I have also heard from other divers that gearing up in sidemount on a moving boat is more complicated that climbing into a BC or twinset and I could definitely see how that would be the case. From a tec perspective I think it would be a fantastic way to do a tec40 style dive, racking up a bit of deco on air or nitrox. I think sidemount is probably one of those things that some divers will do and instantly fall in love with (it will certainly appeal to those who like their gadgets!)
We’ll definitely be looking to bring some sidemount action to DLL soon so watch this space for more news!