Doubles with a single first stage

[Akimbo]

Time in the water and a little conditioning will probably solve the consumption disparity, unless you are cold and then a warmer suit would be a better investment...

… My point is only that it is not all about conditioning, some folks just use more air.

Emphasis on the word probably. Experience is usually the biggest factor with new divers and air consumption. Aquaregia's will likely get better unless his number of dives estimate is out of date.

Female air consumption is a different matter entirely. Many females can easily exceed no decompression times on a single 80 Ft³ cylinder. In addition, they usually have a harder time maintaining core temperature in Northern California. Maybe the answer is to get a smaller bottle for her?

 

[aquaregia]

Yeah, I'm still a newbie: I only have 33 dives in the 6 months I've been certified.

I'm a lot smaller than Troutmaster too, so that's probably less of a problem for me. I'm 5-11, 190lbs with a 44" chest. I looked at my spirometry which showed a 6.5L FVC, which I suspect is high for someone my size, but I'm not all that big. I didn't see a percentile on my printout.

The last time we went diving locally we nabbed her a 72, but she's used to the 80s and finishing with some extra air's not a bad thing. Next time I think I'll rent a 95 and have her use my 80, or perhaps have her use the 95 and save a fill. That's assuming we dive again before I get my 72s hydroed, which might not happen because exams are coming up.

 

[Akimbo]

… I looked at my spirometry which showed a 6.5L FVC...

A little off subject: I have been thinking of buying a Spirometer for freedive training. What brand/model do you use? Are you happy with it?

 

[aquaregia]

Mine was at the doc. I'm trying to get into an AAUS scientific diving class, and they wanted a spirometry exam. For what it's worth, it's a Puritan-Bennett Renaissance II, and the nurse seemed to like it, although he said it was overkill for SCUBA. I guess it has automatic diagnostics in it for lung cancer and stuff.

 

[halocline]

I'm sort of in the "buying junk" field..... I've got about $500 in SCUBA gear right now, which includes an AL80, ScubaPro Mk10 w/ 109s, (etc)

I'd hardly call MK10/109 "junk"; I know you didn't mean it that way. That's a great performing reg that can do just about anything you'd need. If you were to take up ice diving you could easily pack the ambient chamber. If you convert your 109 to balanced/adjustable you'll have basically the same performance as the G250V.

 

[aquaregia]

I've been really pleased with the Mk10/109 actually, way more than a lot of the other regs I've used. I almost converted it to the balanced when I serviced it, but I figured I didn't need to add the complexity with a balanced first stage. Also my LDS tech (who's been diving 40+ years) said he wasn't certain he'd be able to tell the difference, so I figured I probably wouldn't either.

I still need a new exhaust tee for my octo to replace the one that got came off hauling in my buddy a month ago. I'm using a plastic Sherwood as my octo right now which doesn't breathe nearly as nicely as the 109 did, even with the weird supposed lever height issue.