As for that 'well covered' photo of the young lady diver earlier in this thread... I am kinda new to vintage dive gear, how did she manage buoyancy control? Are there some devices I'm not seeing?
It's tough to answer a serious question about that photo, but I know that your question is serious, so I'll try.
In the photo, she's not wearing a wetsuit or drysuit, so there's no need to "compensate" for the compression of a suit. The only change in bouyancy that she'd experience during a dive is the difference in bouyancy between a full tank and an empty tank... About 5 pounds, assuming that she's diving an old 72 cuft tank.
...And 5 pounds is very easy to compensate for using your lungs.
In short, the "norm" for divers of that era was to weight themselves correctly from the outset and do any slight compensation with their lungs... So no BCD was actually necessary.
Actually, when BCDs did come onto the scene a few years later, they were often seen as a crutch that created poor form. In many circles, that's totally correct - there's a lot that can be learned from diving without a BCD.
Interestingly, today's top-of-the-line backplates and wings differ very little from the AT Pak that she's wearing - if you were to build the AT Pak out of metal (instead of plastic like she's wearing) and sandwich a bladder between the pack and the tank... You'd have a modern backplate and wing.
Fascinating how things come back around, isn't it?
