equipment configuration

[Straggler Dave]

I usually dive off Portsea. We may have been in the same boat together.

Possible, but unlikely, as I've only dived with charter boats (Dive Victoria) a handful of times. Normally I dive with Melbourne Uni Underwater Club.

63 cf sounds like a lot of redundancy. When I did my deep-air training (also to about 40 metres - familiar with Winged Sub?) - I used a 3 litre pony bottle slung on the front. That would be about 22 cu ft. In addition to the big 14 litre on my back. (~103 cu ft)

Well, I don't have access to anything smaller than 63cf, so that's what I use. With a single Al100 (11.5L) backtank. I clip the 63 between my left hip and shoulder.

As for the winged sub, that's the only one of the subs I haven't dived yet.... Got to do it this summer...

Yes, we observed rule of thirds, and no, it didn't give us much time for our drills.

Ok... What I do is just make sure I have enough air (using conservative consumption rates) to complete all required deco while sharing air with my buddy. If the dive involved wreck penetration, I'd use the rule of thirds (or more conservative) for that portion of the dive.

eg. Let's say I'm doing a dive where my buddy and I will each need 50bar of air for our ascent. To simplify things let's say I'm using manifolded twins. I'll want to keep a little in reserve even in worst case scenario, say 30bar. So that means I need to begin my ascent with 130bar. Now, if I were to enter a wreck with 220bar, using the rule of thirds I could go in as far as 1/3 of the difference between the pressure when entering (220bar) and the pressure I must have when exiting (130bar). So I must turn around at 190bar and should exit at 160bar. After that, using these rules, I could still stick around outside until I got down to 130bar before ascending, so long as I didn't go over my planned bottom time.