Buoyancy Question - BCD size

[aoumi]

I recently purchased my first BCD, Aqualung wave. I just want to check that it will have enough buoyancy for my needs.

I'm only doing recreational diving, a newbie. I am average height (178cm), but very skinny and weigh 58kg. My height is mostly long legs, so my torso is not long at all.

When I purchased the BCD, the dive shop was at first pointing me to a M size (I think based on my perceived height), but this was a too big. So the S seemed a better fit, and still plenty of room for inflating the jacket, no problems. Aqualungs website rates the S size for a weight of between 54 and 70kg I think, and it gives 13kg of lift.

I ususally will dive a 7/5mm with a 5mm vest. I need about 5.5-6kg of lead usually with steel 12L tank.

So the weight range that aqualung gives in their bcd size chart, is this the safe range of body weight that the S size BCD will provide lift for? Will 13kg be enough lift?

Thanks for your input!

 

[LeadTurn_SD]

Are your certain that 5.5-6kg of lead is what you use? It seems a little low for the amount of neoprene you are using (a 7/5mm full suit with an additional 5mm vest?). But if you are extremely lean, you could be negatively buoyant, and that would account for the amount of lead you need.

If you are sure about your weighting, then we can move forward with a rough "calculation" of the lift you need.

Basically, you need to offset the buoyancy lost by your exposure suit at depth, but we need to estimate that buoyancy based on the amount of weight you are using and the size and type of tank you use.

Best wishes.

 

[Colliam7]

Aqualungs website rates the S size for a weight of between 54 and 70kg I think, and it gives 13kg of lift. I ususally will dive a 7/5mm with a 5mm vest. I need about 5.5-6kg of lead usually with steel 12L tank. So the weight range that aqualung gives in their bcd size chart, is this the safe range of body weight that the S size BCD will provide lift for? Will 13kg be enough lift?

A rough estimate - yes, it will be sufficient. I agree with the comment about being certain of your weighting. But, 6kg PLUS a steel cylinder is not unreasonable, certainly in fresh water. I don't see a safety issue with that unit.