very helpful - so can you advise -if Im going from cold water and steel tanks to tropical and Al do you suggest a waist belt or adjusting the lower tank band for my Nomad XT
You have three options:
1) Add weights to the aluminium cylinders.
This gives them the buoyancy characteristics of steel tanks. There's some drawbacks to that, but not many you'd encounter on a recreational open-water dive. It's a legitimate quick fix for cold-water equipped divers taking a short vacation in the tropics.
It does tend to have a negative image though...but that's offset if all your skills and performance are good. The reason for the bad image is because that's HOW hordes of warm-water divers were TAUGHT to dive aluminium... because their instructors had no experience and learned everything by browsing a few incompatible articles online.
2) Add front & rear D-rings on your waist belt.
The front ones won't be a problem, but the rear ones may be tricky depending on your waist-size versus how far the Nomad XT bladder wraps around you at the sides.
The D-rings front/rear need to be set at distances from the torso side mid-line which equal to the length of the boltsnap and leash that you use for attachment. Smaller boltsnaps and shorter leashes make the job easier. It'll also depend on your bungee method.
Diving aluminium sounds tricky, but actually it's very simple. What's hard is when cold-water BCDs just don't facilitate the adjustments you need to make...
The cylinder band height is simpler....its the distance between your armpit (where you want the valve to sit) and your attachment point on the harness.
Obviously, most waistbelts are considerably higher up than butt-plates... so simply adjust accordingly.
3) Buy a Deco Sidemount rig for $250.
It's perfect for warm-water recreational diving and it'll save you a tonne of space and weight in your luggage. You'll also benefit from getting experience setting up and dicing a dedicated warm-water rig (Mexican cave style..).
