mwilding once bubbled...
Another ScubaBoard member wrote this
Unfortunately, this testimonial has some hole in it. The physics as described are technically (narrowly) correct, but its assumptions are problemmatic, which makes this "Garbage In, Garbage Out" insofar as its conclusions.
For example, it assumes that you dive with your BC 100% inflated. The reality is otherwise, which means that the air in the bladder can and does shift around. Similarly, since nearly all Jackets have smaller bladders up around the shoulders than down by the waist, it means that the illustration's center of lift is incorrectly marked (its too high).
Also note that unlike the illustration's depiction, it has actually been possible to locate lead on the back of your weightbelt for the past 50+ years, which means that this front bias is possible, but easily correctable (for free).
Claims such as "[they] dry out faster than BC's with thick, heavy padding" have nothing to do with the design. If you want a fast drying BC, don't get one with thick padding.
Claims of BP/Wings generally being cheaper are an interesting one. Sure, you can find expensive BC's, but there's tons of darn good cheap ones too. The Tusa Liberator is one example, and it can be had today for as around $200. To match that with a BP/Wing, you have to roll your dice on Ebay, because the dealer-supplied Halcon is over $500.
Meantime, the claims about any system being "more streamlined" are just that: claims. No one has cold, hard Engineering data that actually proves it. And without data, its just an unsubstantiated opinion...or Marketing Hype. If someone's going to make the claim, they had better be able to come up with the data. Besides, even if there was a 10% difference in drag, does it even matter if you're doing drift dives?
Finally, while there's good things to be said about a BP/Wing arrangement, note that the described system has all of its ballast in the BP, which means zero budget for ditchable weight. The reality is that there are trade-offs to be made between what might be "optimal" for trim versus other performance parameters for the overall dive.
The bottom line to this is that good gear certainly helps, but even the best gear won't bail out a diver with poor skills: good skills transcend the equipment you happen to be using.
-hh
