Sidemount Diving: Take that Weight off Your Back

Don't you love those agonizingly long, uncomfortable rides by inflatable boats to the dive site? What about staggering about on a rolling deck, trying not to fall with a tank on your back? Or descending to the stern swim platform toting a tank? As for climbing the boat ladder after a dive with your tank on . . . well, there's a fix for all that.

Just as NASA's inventions for space exploration led to us having nonstick frying pans in our kitchens, we recreational divers reap the benefits of inventions for technical diving. Side-mounted tanks is one of those, and something older leisure divers should definitely consider.

Technical divers need to carry one gas for use on the deepest part of their dive, plus a different gas mix for getting there and back, and an oxygen-rich gas for decompressing. Because they can't carry all the tanks required on their backs, some industrious thinkers came up with side-slinging two of the tanks from D-rings of their technical diving wing-style BCs. Closed-circuit rebreather divers, who need to carry open-circuit bailout rigs, did something similar.

How can recreational divers benefit? Side-slinging a tank means that you can access your tank valve easily, so if, say, a regulator goes into free-flow, you can avoid losing any air simply by opening the tank valve each time it's necessary to inhale.

As for us older divers and those who suffer with bad backs, there are plenty of distinct advantages of sideslinging a tank rather than wearing it on your back. You don't need to hitch it to yourself until you're about to fall into the water and experience joyful weightlessness. You can sit in an inflatable in relative comfort, your tank standing vertically next to you. It's equally easy to unhitch a tank and pass it up to a crew member when you get picked up after the dive. In fact, boat crews can do all the heavy lifting, because you're only carrying the tank while you're in the water.

So how do you do it? The tank has a fastening around the neck and a camband around the lower part of its body, both of which are equipped with large piston clips that hook onto strong, stainless steel D-rings on the right sort of BC. There are even BCs designed specifically for sidemount diving, such as the Hollis SMS100, the Scubapro X-TEK Sidemount, the XDeep Stealth, the Mares XR Pure Light, the Dive Rite Travel Pac and the Finnsub FLY sidemount wing set. They're all designed to make the diver as sleek as possible in the water.

You may need to reconfigure the hose of your regulator. A long hose that allows you to route it around the back of your neck before the second-stage reaches your mouth is a popular method. The hose of the octopusrig is bundled up and stored under elastic straps that pass round the center part of the tank or are worn on a necklace. The direct-feed hose for the BC might need to be longer, too, although the high-pressure hose for the pressure gauge can be really short.

When you're ready to get into the inflatable (or onto the swim platform of a bigger boat), sit on the side with your tank standing upright beside you. When the time comes to dive, turn on your tank and put the regulator in your mouth, clipping the top piston-clip to a D-ring high up on your BC. The moment before you enter the water, bend down to pick up the bottom piston-clip, attach it to the lowest D-ring on your BC, and lift the tank as you do so before rolling into the water. After you dive, passing your side-slung tank back up is equally simple and effortless.

Cave divers like to side-sling because they can always detach the lower piston-clip, and with the tank still secured by the upper clip, pass the tank ahead of them through a tight space. A wreck diver might find occasion when that's useful, too.

For us sport divers, it means we never have to carry the weight of a tank on our backs. I can hear many of you "seasoned" divers shouting, "Yes!" in unison. Go to your dive shop to ask how you can adapt your dive gear, including your BC, to enable single-tank sidemount diving, or what gear they have available specifically for it. I guarantee it will take a load off.

-- John Bantin