Hatul and Evad:
I believe you are both right but (from what I understand, sorry if I am wrong) you don't talk about the same thing:
- I agree with Hatul that this huge chunk of metal with a long wing is sometimes encumbering (for example you can't put it inside the standard crate used by many dive centers ; or it's impossible to store in some tank holders on boats, I've seen it)
- I agree with Evad that (depending upon the plate) some BPs provide excellent support for the back, and actually more so than many traditional BCDs.
Bottomline from the above posts:
- If you need less than 10 pounds of lead, you won't notice much difference regarding buoyancy control & trim between a BP/W and a jacket BCD, and a
simple jacket BCD will be a bit more streamlined than many wings, and will provide a better distributed support at the surface. There are other factors (comfort, freedom of the chest, paunch hidden or not
, weight and bulk, overall price, robustness, dumpable weights, modularity vs convenience, adjustment, style, etc) that will also play a role in your choice.
- If you need more lead, then you will probably notice that BP/Ws are superior to jacket BCDs regarding trim and (often) comfort on your back, and with a SS BP you will have less lead to carry.
That a diver really
needs the lead he or she
uses is another story.