NewB BP/W Question - This wing for a single tank?

[cool_hardware52]

I'm not sure of the relationship between neoprene and pressure, but assuming it's linear like air, it would lose roughly 25% at 15 ft (half at 33ft, so half of a half at 16.5 ft). That depends on density, and I'm not sure of the density of neoprene. I'm sure it's closer to air than metal based on it's buoyancy at the surface. I need to add air at 20 ft with a full tank so that makes sense.

Suit compression is non linear with respect to pressure and the change in pressure with respect to depth is also non linear,, but it's clearly evident to any diver that wetsuits compress, and thick wetsuits compress more than thin ones.

My point is that in a heavy suit you don't need to start the dive negative by the weight of the gas in the typical single tank, the compression of your suit will easily offset the 5-8 lbs of gas in a typical single cylinder.

That you need gas in your wing at your shallow stop confirms this.

Tobin

 

[Bossman]

Agreed, I'm not negative at the beginning of the dive. I took a PBB class and dialed it in. Surprisingly, once dialed in, I ran my configuration and ballast through the wing lift calculator. It calculates 0.0 at the beginning of the dive I really have to exhale hard to get down, and it takes some work to vent early and empty the wing fully to hold a safety stop at the end of the dive. But it's worth it to ditch the extra weight. The real answer is a dry suit, and ditch the thick wetsuit.

I know you're inferring that I can get by with a 30 lb wing, and you're probably correct. I like the 40 to offer a little margin of error ( there is a certain depth where my suit could lose more than 30 lbs, althoguh unlikely I'd be at that depth without a host of other problems) or to help compensate for a buddy who needs assistancy during a wing failure.

 

[cool_hardware52]

Agreed, I'm not negative at the beginning of the dive. I took a PBB class and dialed it in. Surprisingly, once dialed in, I ran my configuration and ballast through the wing lift calculator. It calculates 0.0 at the beginning of the dive I really have to exhale hard to get down, and it takes some work to vent early and empty the wing fully to hold a safety stop at the end of the dive. But it's worth it to ditch the extra weight. The real answer is a dry suit, and ditch the thick wetsuit.

I know you're inferring that I can get by with a 30 lb wing, and you're probably correct. I like the 40 to offer a little margin of error ( there is a certain depth where my suit could lose more than 30 lbs, althoguh unlikely I'd be at that depth without a host of other problems) or to help compensate for a buddy who needs assistancy during a wing failure.

If your suit is truly +34 I would not recommend a 30 lbs., a 35 or 40 is appropriate. My comments are regarding your total ballast.

If you need gas in your wing at your shallow stop with a near empty cylinder you more ballast than I would carry for the same application.

Tobin