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Simon, though you have some point in noting the importance of airway protection, note that the term "most accidents happen at the surface is a very vague one. It neglects the fact that the cause most accidents lies either beneath the surface, or even above, before the dive, in preparation, choice of divesite, "buddy", gas management, complacency. As for surface-born causes, I knew 2 divers who were fond of proper flotational design of their stuff, they were drifting at seastate 4 and became seasick , but managed it to swim back to the boat. Another girl in the baltic drowned when she vomited, another diver was lost at the surface, never reappeared again , when they were surprised buy a sudden gale which caused a seaward current. Mostly things are well when a diver is still able to swim by his own means. For a long swim, you must decide which part of your gear has to go. Nice to have something which offers flotation. Matthias Simon L Hartley schrieb: > > Hi George, > > Thanks for your reply. I can see your point and I've no problem with > changing the way I do things if it promotes poor technique, not that anyone > ever listens to me anyway :-) Most of the newer DM's/Instructors locally > have been buying Apeks regs of late but I think this is more Uncle Geoff's > influence than mine (still insist on donating an "occy", putting it on some > sort of clip, in a pocket or tucked under a chest clip and buying bloody > awful jacket style BC's to go with them). > > If the priority is having weight to ditch then I can see why it is best not > to put the only weight you carry (apart from the alum plate and STA, which > you can't do anything about) on a belt or have a canister light. However, > if your carrying a lot of weight with a wetsuit would it make some sense to > spread it around? A weight on the tank does seem to improve trim and > ditching just six pounds or so should make you positive even with a full > aluminium tank at the start of a dive (unless I'm missing something). > > I noticed that Halcyon seems to have ditched (no pun intended) their fixed > keel weight and now offers a series of weight pouches with ditchable > weight. Seems to me to be more of an entanglement risk and rather a > complicated solution (like the ACB system I bought a few years ago and have > never used). The site also mentions that "more than half" of diving > fatalities occur on the surface. What it doesn't mention is whether this > is because they failed to ditch their weight belts (likely), ended up face > down without a buddy or other help around (where the tank weight is meant > to help) or met with some other misfortune. This sort of detail would be > useful in determining whether concerns of airway mitigation have any > validity in the recreational environment I'd have thought. > > Cheers, > > At 06:44 7/01/2002 -0500, you wrote: > >Tank weight is pure bullshit. The correct answer is dive with a buddy and if > >you have a big problem on the surface, take off the tank. I tried one of > >those pieces of shit and guess what happened? We started the dive with a > >full 80 of 30X30 and dropped down to catch lobsters. The vis was horrifying > >so we aborted. When I got to the surface, my bc hose broke. Now I had a full > >tank and no inflation and was not about to sit there dogpaddling like a fool > >to stay up. I was diving with Alton and Errol, and one of them held me up > >while the other one took the stupid ass tank weight off of my tank. > > > >This is not something to be telling people to do, it is total bullshit, > >dangerous, and extremely stupid. > > > >-----Original Message----- > >From: Simon L Hartley [mailto:shartley@sc*.ed*.au*] > >Sent: Sunday, January 06, 2002 8:55 PM > >To: donburke56@ne*.ne* > >Cc: techdiver@aquanaut.com > >Subject: RE: neutral AL 80's > > > > > >Hi Don, > > > >I'm not really sure I'm game to CC this to the list... ...what the hell > >I'd rather be made to look a fool than keep doing the wrong thing. > > > >At 07:45 6/01/2002 -0500, you wrote: > >>As long as I've got you talking about weights on tanks, I have a minor > >>dilemma. A portion of my diving is not technical by any stretch of the > >>imagination and involves quite a bit of time bobbing on the surface waiting > >>for something (another diver, a tool, a camera, whatever). With the wing, > >>there is a tendency to pitch forward. > >> > >>My old jacket BC is much better on the surface, but I'd rather not deal > >with > >>it underwater. Besides, it is getting old and I'd rather not replace it > >>when it dies. > > > >Before I bought my Halcyon Pioneer 27 a couple of years ago I experimented > >a little with surface flotation (using my old Scubapro stab jacket and a > >home made wing and harness). Not stringent or exhaustive by any stretch of > >the imagination but I haven't seen any work on this so I thought it was > >worth playing around a little myself. If there was little air in the tank > >(aluminium) then the jacket style BC would just as happily float me with my > >face in the water given half a chance. Despite appearances jacket style > >BC's are not life jackets and are not, IMHO, designed to keep an > >unconscious divers face out of the water. Air in a BC can stift to balance > >various competing forces (it's been a few years since I did my coxswains > >and had to learn about centre of buoyancy, centre of gravity, etc), life > >jackets usually have fixed foam flotation cells. > > > >FWIW, I feel the wings float you higher in the water even if they don't > >have that armchair feeling of a stab jacket. I used stab jackets for > >nearly ten years but wouldn't go back. > > > >>I've been thinking of using one of those exercise weights on the tank, but > >>would rather not introduce another entanglement point. > > > >I got the idea for a tank weight from the Halcyon web site (Halcyon make a > >couple of types of tank keel weight systems). I didn't want to spend a > >fortune getting a hunk of lead sent out from the US so I used a standard > >three pound weight threaded through the top tank strap (I found six pounds > >annoying but may be more effective as a keel weight, the Halcyon weight is > >six pounds). There is a picture on my web site (under "Putting it all > >together" "Weighting and thermal protection")... > > > > http://www.scu.edu.au/schools/esm/staff/pages/shartley/projects/gear/ > > > >As far as being an entanglement risk possibly although it does fit snuggly > >to the tank and no problems to date. Also increases your vertical profile > >though (I have the old style wing too which requires a STA, making matters > >worse). I do feel this promotes a more stable face up position on the > >surface though. > > > >Cheers, > > > >Simon -- Send mail for the `techdiver' mailing list to `techdiver@aquanaut.com'. Send subscribe/unsubscribe requests to `techdiver-request@aquanaut.com'.
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