[Mark Davies]

Originally Posted by chrisch

Two options really.

Err, three. Single 15 tank with H-valve.

Same gas as a 12 and pony; compact, balanced, tidy - and interchangeable with twins. Okay, not exactly the same level of absolute redundancy (but quite sufficient), and it does require a bit of gas-management discipline, though throw in an air integrated computer and that's sorted. A great alternative to your twinset for those shore dives or RHIB dives where a lighter rig makes more sense. And a lot cheaper to buy and maintain than twin 7s.

As for Oceanic regs, I've been using Omega IIs exclusively for years and been perfectly happy with them. I like the fact the second stage is so light and that they can be used any way up. However, I do run them from Apeks DS4 first stages - as they perform very well and are nicely compact.