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LJ_OREILY:Is there a calculation or formula to figuring out how much lift one would need, with say a 120 HP tank, 7mil suit, for a 210lb person?
LJ_OREILY:Is there a calculation or formula to figuring out how much lift one would need, with say a 120 HP tank, 7mil suit, for a 210lb person?
*Floater*:The 120 HP tank has a buoyancy swing of about 9# and to be conservative assume your wetsuit loses 75% of it's buoyancy at depth, or maybe all it's buoyancy to be even more conservative. Now how much do you need to sink it at surface waters?
As an example, let say you need 24# to sink it at surface, so it loses maybe about 18-24# at depth, and your hood and boots lose a few # too, then you could probably get away with a 30# wing if the 75% figure is correct, but 35# would do for sure. This analysis assumes you don't dive otherwise over-weighted. i.e. you are neutral close to surface with an empty tank and no gas in your wing. With a drysuit you'd need even less lift.
Some people want their wings to be able to float their heavy rigs on the surface (without them strapped in i.e. no wetsuit buoyancy), so that's another thing to consider if you are so inclined.
I'd actually like to know how much buoyancy wetsuits do lose in %-terms. The figure I've heard on the internets is 67% at 30m, but it's just what someone said. If anyone knows then please let me know.