BP/W lift?

[Patoux01]

7mm wetsuits can lose quite a bit more than 2KG of buoyancy when fully compressed, probably more like 6-8KG. The most conservative way of determining your wetsuit's potential buoyancy loss is to put it in a mesh bag and see how much weight it takes to sink it. This is it's total buoyancy, and cannot lose more than that amount.

It doesn't even have 6-8kg of inherent buoyancy... or I wouldn't be able to dive it with 7kg and 2 aluminium tanks . You're also unlikely to have a suit compressed to 0 volume. So I'd rather take a guess than oversize it, thick neoprene doesn't belong below 30m imo anyway.

Please do not size a wing with additional lift to assist another diver. Rescue protocols specify using the other diver's own BC, dropping weights, or a combination of the two. There was recently a big thread on this very topic.

Please explain how I can use a failed BC? Some don't use droppable weights (I'm of those, and don't consider myself in danger, ever. I wouldn't need the BC to get my ass up), I also don't want to fiddle with those ****ty weight pockets some people think are so handy. PADI recommends using your own BC when getting someone up... I recently quoted that somewhere else, page 166 in rescue diver manual...

But that's off topic, so I'll leave this here and let Yoyoguy decide for himself...

 

[cool_hardware52]

It doesn't even have 6-8kg of inherent buoyancy... or I wouldn't be able to dive it with 7kg and 2 aluminium tanks . You're also unlikely to have a suit compressed to 0 volume. So I'd rather take a guess than oversize it, thick neoprene doesn't belong below 30m imo anyway.

Wetsuits vary widely in buoyancy. The type of neoprene used, the number of times it's been compressed, how deep it's been dived etc.

Having said that most 7mm suits on somebody of normal stature will be 16-24 lbs positive.

Keep in mind that if you are diving with "2 aluminum tanks" you have 2 regulators, each being about -2 lbs If these are configured as banded, manifolded doubles you have tank bands and a brass mainifold which typically are about -4 lbs together.

One does not need to compress neoprene to zero volume for it to lose all of it's "surface" buoyancy. One need only compress the "foam rubber" until it is a solid block of rubber. Solid neoprene has a specific gravity of ~1.3

Throw a DUI CF200 drysuit in the pool sometime……..

Tobin