BCD Weighting, Back Inflated vs Jacket

[labaum]

I know the answer is to "get in the water and figure it out", but might I ask a generic question?
All things being equal, does a back inflated BCD require the same weighting as a more traditional jacket style?
I'm contemplating going from a Scubapro Accent to a Knighthawk and was wondering what to expect from a weight perspective. Much thanks

 

[fisherdvm]

You can contact the manufacturer for the exact bouyancy of the BC, and not have to jump in the water to figure out. Or attach weight on it, and see how much it takes to sink it. Subtract it from your current BC bouyancy, then you will find out how much more or less weight you would need.

I know some divers who bores holes on their plastic back plate to lose a few ounces of buoyancy... But it would just make more places for moulds to grow...

 

[fisherdvm]

I can't see a reason why one would have more intrinsic buoyancy than the other. It depends on what they use for the back plate - whether it is a steel/aluminum plate, solid plastic, or hollow plastic.

But, as I understand, most back inflate have more functional buoyancy than a jacket style, especially if you wear a small or XS BC. Once you get into a larger BC, back inflate and jacket inflate usually has about the same functional bouyancy.

 

[Bob Vincent]

The weighting? There should hardly be a difference. Your not talking plates. Were steel vs alum. come into play. Most plastic backplates are going to be were the difference is but there shouldn't be a major difference one time jumping in the water you'll know the 1lb are so to add or subtract.

As per buoyancy a back inflation should have more lift, "they are supposed to be more techie". But this might not be true with a rec type. I use a Oceanic Probe it has 54lbs of lift for everyday in and out pleasure diving. But were doubles come into play the OMS has a 100lb lift.

But as I said rec type shouldn't be way off in weighting.

 

[spectrum]

I would expect it to be very close if NOTHING ELSE changes. Just make a conservative orientation dive with the thing and do a good buoyancy check when the cylinder is running low.

To be on the very safe side add a 2 pounder and make sure that you have some other small accessible weights on for the dive that you can shed during the test. This may mean putting some of the weights on clips or in pockets so you can freely add and remove.

If we're talking fresh water you can take a low tank into a pool. Make sure everything is sopping wet and saturated before you consider making decisions. Your profile has no useful info like where you might be so fill that out when you have a moment.

Pete