Posted by Gerry Smith on March 12, 2001 at 12:05:17:
In Reply to: Re: reserve buoyancy posted by MHK on March 12, 2001 at 10:54:53:
Mike,
The origin of my post was a mindset similar to Frank's (I've dived wet steel for a zillion years, how can it be unsafe) opposed to my normal inclination to learn more. I believe the numbers to be accurate (see the replies to Steve's and Frank's posts) but even if they're off by a bit, the result is that maybe others with the same disregard for steel/wet warnings might take them more seriously.
The neutrally buoyant body assumption matches most people, but the caveat further down covers those who are positive or negative. The assumption that everyone will offset buoyancy with weight is simply what divers do on every dive. Maybe if they think of it a bit more systematically than a simple (uhhh, I'm still buoyant, add more lead...) they'll be a bit safer.
Taken as a whole, the analysis supports your warning, which surprised me to be honest about it. But it also points up the possibility of getting into trouble with aluminum tanks or SS back plates.
A blanket pronouncement strikes many, especially the more experienced, as dogma to will be discounted. Backing up the pronouncement with numbers - even numbers that disagree in a small corner of the envelope - might jolt loose a thought or two, resulting in more aware divers.
Q for you: One of the sources I used (huronscuba.com) quoted buoyancy of the Heiser LP 104 as -15 lb full. Do you know if this is accurate? Also, how much weight does a SS single tank adaptor add?
Thanx
GS