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Hello All Sorry to not respond to some posts earlier regarding this thread. I was doing real world stuff! First off, the 'checklist' I go through (outlined previously) is not rocket science. I do it for any BC I am using, including on the one I borrowed recently. Another thing I do as part of a checklist is after being fully suited I check to see that all the pull dumps are not stuck under straps. Diving with three finger mitts I do not cut off the little black balls. I just make sure they are not someplace they aren't supposed to be before I jump off the boat. As to why buoyancy might change with a change in position: it is simple. Sometimes when you change position, you do change the depth that the wing and the 'bubble' are at. If you are doing a 10fsw/3msw deco stop, and change position from a prone swimming position to an upright sitting position, the wing could actually change depth by as much as a foot. (If you are one of the herd of deco divers holding onto the anchor line, or leaning on a deco bar, you will not notice the subtle change in buoyancy. You notice it doing a free floating hang, under an SMB.) The bungees help because first, with the little bit of added pressure in the wing, the bubble will not expand as readily when it moves up a little. Also, I believe, as some of you point out, the bunged wing 'limits' you ability to change position. This in turn limits the wing from changing depth. I have done enough free floating hangs, and messed up enough of them too, to know that this is fact. As for cold water changing the bungee elasticity, well like I said before, maybe I'll do some experiments this winter ice diving. And yes, a bungee wing has more failure points than one without, in a sense. After all, all you 'I have less failure points than you do' divers will agree, if all my bungees were to break (fail) then my wing would just like yours :-). And I heard someone paging me about the extra inflator being a problem in the double bladder argument. I take Bill Mee's word for it that they are subject to saltwater corrosion, etc. I have also heard tales of jammed inflators first hand, and seen some video of a diver having that problem. But I think the good outweighs the bad, the statistical chance of both inflators going on the fritz at the same time is slim. As for accidentally inflating the second bladder there is no chance. When diving dry there is no lp hose to the inflator. If there is any problem that affects the primary bladder, ei reg shut down, inflator stuck, etc., I abort the dive. Usually that means I go no deeper and then ascend and am only venting gas from the bladder. No need to add any gas. If I have to go deeper and need buoyancy I use the suit for the short time needed. Then its back to dumping gas on the way up. If its a rip and the wing is deflated, I abort the dive. I put gas in the suit to maintain depth, and use this uncomfortable option until I can switch the lp hose off my suit and inflate the backup bladder. Then I can deflate extra gas out of the suit. On the odd occasion I dive wet, I install a lp hose to go to the backup bladder/inflator, leave it disconnected, but tied with reel line to the inflator. A rip in the primary bladder is the only scenario where I need to connect it. A shutdown etc. means after aborting the dive ascending only, and therefore just venting gas out of the wing. I wear the primary inflator over the left shoulder, like I was originally taught. The second inflator is tucked in between the the wing and the tank on the right side, held there with a slice of tire tube. No fuss. Tom -- Guns and Armour of SCAPA FLOW 1998 Underwater Photographic Survey of Historic Wrecks http://www.gunsofscapa.demon.co.uk -- Send mail for the `techdiver' mailing list to `techdiver@aquanaut.com'. Send subscribe/unsubscribe requests to `techdiver-request@aquanaut.com'.
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