KITTED-UP
4 . Buoyancy systems
In the first days of wetsuits , as the diver descended the water pressure crushed the bubbles in the neoprene causing a couple of things to happen – firstly they got a bit colder , secondly , they reduced in volume and so the diver got heavier . The cold was just dealt with as dive times with relatively small tanks were not too long , but the overweighting had to be dealt with either by bouncing inelegantly along the bottom , or some divers wore two weight belts , including a small one that could be dumped at depth then retrieved from the bottom of the shot before coming up .
Surface life jackets started to be worn where the diver could take a breath , blow into the jacket then pop their regulator back in . Fenzy took this idea and added a small cylinder to the jacket - to add air , the diver simply cracked open the cylinder valve . With this they created the Adjustable Buoyancy Life Jacket ( ABLJ ). Eventually an additional hose from the first stage was used via a tee off the second stage hose , to supply an inflator so the small cylinder wasn ’ t needed . While adapting a surface life jacket just about worked , wearing the thing all day was a bit tedious
and underwater , had the floaty bit in the wrong place . Incorporating the buoyancy cell into the harness instead seemed like a sensible idea and the stabilizing ( STAB ) jacket was born , where the cylinder , regulator and jacket was a single unit . This is the configuration that the vast majority of divers use today , albeit with the addition of clips and pockets and all sorts of bells and ( literally ) whistles .
There has been a move in recent years to move back to a simpler system using a webbing harness , metal backplate and simple buoyancy cell ( called a wing ) behind the diver , creating a more streamlined , simpler system , although many manufacturers seem to be wedded to the “ more clips and D-rings are better ” designs .
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