March 25th, 2008
While test diving our new Classic 360 Wing the other night I experienced some roll and immediately thought I was having air shift in the bladder. Then I realized I needed to make some adjustments. The TransPac I was wearing was last worn with a single tank, plus I am used to diving the O2ptima or sidemount. I hadn’t had a set of heavy, steel doubles on my back for over a year. All I needed to do was tighten up my harness to support the gear I was now wearing.
As I thought about the roll issue I thought about what my ski instructor had told me over the holidays. You adjust the boots and bindings for the type of skiing you do; the more aggressive you ski the tighter the boots and bindings should be. Technical divers need to look at adjustments the same way. Variations in drysuit and wetsuit selection can change the way your harness fits, changing cylinder sizes like heavy steels at home to aluminum 80s in Mexico changes the way your wing handles the cylinder weight and your trim.
I see more and more divers these days wearing loose waist belts and shoulder straps on their harnesses. If you ever see experienced cave divers doing long swims they wear their harness with a tight fit at the beginning of the dive and sometimes will tighten it more as they get to depth. The diver is suspended by a harness with a wing sandwiched between him and the doubles. It’s like you are a sky diver; how many sky divers would jump from a plane with a loose harness? You want to make sure the harness is tight when diving doubles so any change in buoyancy or body movement happen together and not a cascade event, when you point your body down to swim under a ledge and the cylinders join you a second later. This may not seem like a big deal, but it can cause you to get out of trim quickly and the moments it takes to recover can mean loss of control. A skier needs to know that when he moves his feet inside the boots that the boots attached to the bindings and skis react immediately or he may fall or loss control.
I have watched divers very loosely fasten the waist belt on the harness. I even had one person tell me he didn’t like any pressure on his stomach. Control is having your equipment move when you do and not a few seconds later. Look at your adjustments and check them again underwater and make sure your equipment is secure. I am confident you will have a more enjoyable dive.