Guidelines for lift? Rec diving, so calif

[FishLips]

Hi everyone.

I'm a new diver looking to buy my first BC. I'm female, 130 pounds, and will be doing most of my diving in So Calif with a 7mm suit, and the Caribbean. One BC I'm looking at only has 21 pounds of lift - what is a good rule of thumb for how much lift I'll need? I'm pretty buoyant (higher fat %, I guess), so I need more weight than my husband who weighs the same.

Thanks, fishlips

 

[scubasean]

Hi everyone.

I'm a new diver looking to buy my first BC. I'm female, 130 pounds, and will be doing most of my diving in So Calif with a 7mm suit, and the Caribbean. One BC I'm looking at only has 21 pounds of lift - what is a good rule of thumb for how much lift I'll need? I'm pretty buoyant (higher fat %, I guess), so I need more weight than my husband who weighs the same.

Thanks, fishlips

Regardless of setup and your body type as compared to others, if you properly weight yourself (this is the key...) so you are neutral at your safety stop depth when you have just 500 psi or so with no air in your BC, then all you probably need to support is the weight difference caused by adding air to your tank, or roughly six to eight pounds, depending on which tank you use.

Seems like 21 is plenty.

Sean

 

[MechDiver]

if you properly weight yourself (this is the key...) so you are neutral at your safety stop depth when you have just 500 psi or so with no air in your BC, then all you probably need to support is the weight difference caused by adding air to your tank, or roughly six to eight pounds, depending on which tank you use.

Seems like 21 is plenty.

Sean

This would be true with a drysuit or skin, but not, IMO, for a 7mm wetsuit. Your worse case lift wise will be with full tank and at depth, where you lose the buoyancy of the wetsuit due to compression.

I would not dive coldwater with less than 35-36lb lift, but you'll have to determine what works for you.

MD

 

[MyDiveLog]

You'll probably be wearing, with a 7mm suit and an AL 80, in the neighborhood of 10 - 15 lbs of wt. ... the 21 lbs of lift should be fine. Remember that, if you are properly weighted, the BC is only providing a couple of pounds of lift (a couple of small puffs at depth). If you'll be doing only warm water diving, then the 21 lb lift will be fine; you'll be wearing little or no weight.

Something you need to consider, though: The discussion above is about being neutrally bouyant at depth. Sometimes you'll want the BC, reg, and integrated weight to float on the surface. I had a female dive buddy that had a BC with the same lift as the one you are looking at. Even when it was fully inflated it wouldn't float at the surface, and she wasn't over-weighted.

Tank(s) can have very different bouyancy characteristics: the AL80 is about 3lbs negative at the beginning of your dive, but my Steel 80 is 6 lbs negative when full. I have a dive buddy whose tank is 10 lbs negative when full. If you're thinking of diving with twin tanks (for deeper, decompression diving) than 21 lbs of lift won't be enough.

My advice is to select a BC based on the tanks & type of diving you'l be doing. Once you know how much weight you need, confirm that it'll float at the surface with that gear/weight configuration before you buy one.

Good luck!

 

[FishLips]

Great information you guys, thanks for taking the time to help. I think you just saved me from getting something that works great, in 50% of my diving! Now I can have an intelligent discussion with my LDS.

Thanks a bunch,

FishLips