A spreadsheet comparing gas capacity and buoyancy of various tanks

[dfx]

I really prefer litres. This way I can see my full pressure and know how much gas I actually have. A 16l tank at 200 bar has less gas than the same tank at 230 bar.

This really has nothing to do with metric vs imperial. You can apply the metric convention to imperial units as well, or the imperial convention to metric units. Instead of a 16L 200 bar tank, you'd have a 3200L 200 bar tank. Of course you get more air if you overfill it. But I'm willing to bet that most people, most of the time, are interested in how much air a particular tank holds at the rated fill pressure. The imperial convention tells them right away without having to do some math first.

I'm not saying that the metric convention doesn't have its uses and I'm sure that for some people it's more convenient that way, but personally I prefer the imperial convention (even if used with metric units).

 

[tplyons]

There's some great analysis here!

However, my criteria were a little bit different than you. Had to be shorter than an AL80 (I'm a pretty short guy) and preferably 7.25" diameter. Unfortunately that means my ideal tank in this situation is missing, good old HP100's so I downloaded and plugged them in, and am quite happy with the numbers on here and they match my back of the envelope calculations that I made when purchasing (30% more air than an AL80 with a 3442 psi fill, and even with a 3000 psi fill, I have 15% more air in a smaller package)

Some good work, do you have any intention of filling in the rest of the commonly available new tanks?

 

[altaskier]

Added HP 100, LP 108.

 

[Kevrumbo]

Wouldn't it make more sense to calculate the values for "reserve" not in terms of pressure (500 psi), but rather in terms of amount of available gas?

Your SPG reads in Pressure Units --NOT Volume Units. And it's much easier to figure out remaining gas on-the-fly for revising modified Thirds and Rock Bottom (or gas pressure reserves available for a Lost Buddy Search) etc -using Bar pressure untis than PSI.

Diving Metric: Benefits of bar and meters