I agree with
mahjong's assertion that "where you put the weight should depend on how you trim out."
It's a trial and error process that must take place in the water and with all of your gear on.
What works great for one person in a certain configuration (number of tanks, tank type, exposure suit, etc.) might be suboptimal
for a different person with his gear setup.
What works great for one person in a certain configuration might be suboptimal
for that same person using a different gear configuration.
Two things to keep in mind:
- Without some sort of quick-release mechanism, weight pockets positioned on the tank cambands aren't readily ditchable, particularly if you are wearing a "standard" drysuit or thick wetsuit.
- Depending on the tank(s) and amount of required weight, positioning 100% of your lead weight in camband pockets might make you more prone to "turtling." YMMV.
Know that you can choose to position two weight pockets on the cambands in a few different configurations (2 on top, 2 on bottom, 1 on top & 1 on bottom).
Common: If you are trying to correct head-up/feet-down trim issues, then putting more weight on the upper camband might make sense. Try both pockets on top.
Less common: If you are trying to correct head-down/feet-up trim issues, then putting more weight on the lower camband makes more sense. Try both pockets on bottom.
In my setup, I have some ditchable weight positioned at my hips with a weight harness. If I put both weight pockets with the rest of my lead weight on the
top camband, it promotes
head-down/feet-up trim. If I put both weight pockets loaded with the rest of my lead weight on the
bottom camband, it promotes
head-up/feet-down trim. In either case, I can compensate for the trim issues with body positioning and bubble placement inside my drysuit...but I find it annoying and uncomfortable to deal with that throughout an entire dive. That's why I settled on putting one weight pocket on the top camband and the other on the bottom. Each weight pocket is snugged up close to the STA, so it doesn't throw off right-left balance. Eh. At least that's what works for me.
Figure out what works for you.
You mentioned that you used 20 lbs. of lead weight when diving in CA. I'm going to assume that that weight requirement was with a conventional jacket BCD (usually 2-4 lbs. positively buoyant), an AL80 tank, and a 7mm wetsuit. Given the same exposure suit and tank combo, once you switch over to a SS BP (5 lbs. negatively buoyant), you might only need 12 lbs. of lead weight. (As a newer diver, you really should have some ditchable weight positioned at your waist, so some of that should be on a weight belt/harness.) At first, you can try putting all of the weight at your waist, which will probably result in head-up/feet-down trim (like 99% of the newbies out there). Then, in small increments, experiment with shifting small amounts of weight to weight pockets positioned on the cambands. Try all 3 weight pocket-camband configurations I mentioned above.
Oh, and by the way, make sure that you do a proper weight check with your new BP/W
before you spend lots of time optimizing trim. The correct order of operations is: (1) determine weight requirement, then (2) experiment with the placement of the weight.
Have fun out there...