Average Gas Consumption?

[scubadada]

smorneau,

You might find it useful to follow your air consumption by calculating your surface air consumption (SAC) This would make it tank independent and would allow you to judge the effects of water temperature, other conditions, exertion, experience, comfort, gear, etc.

Good diving, Craig

 

[aquaregia]

TMaybe it's time to buy that used HP100 sitting at my LDS. I have not got a BP/W YET, so doubling is not an option.

I wouldn't recommend doubling anyway, it just means you try to squeeze two dives out of them and wind up in exactly the same spot. Either that or you need two sets of doubles so you can do a 'two tank dive'. Keep in mind that owning one HP100 might also land you in that Goldilocks hell of unmatched tanks.

I've got a really weird fleet of tanks that I've almost managed to make sense (barring one of the 8" AL80s and one WK 72), but if you've got the cash I'd probably recommend getting something reasonable. Tanks don't wear out easily, and tend to hold their value, at least better than most dive gear.

 

[spectrum]

My average hour long local (local to you) shore dive to the 25-35 foot range and back uses about 40 CF of air so yes there probably is room for improvement. Keep in mind that we are unique so YMMV.

The important thing for you is to dive with a spirit of continuous improvement. Over time, technique, comfort and experience will grow and most divers see a significant boost in range. I think everyone I have been diving with can make such a dive for a hour on an 80. I will say that I have seen divers wait years for the switch to flip and some were air misers from the start. Just be true to yourself and have fun.

As for cramping the style of other divers just be up front. It's true that for some dives it would not be a good fit. It's more about safety and maybe reaching an objective that may take X minutes. Other than that I'd rather make a :37 dive helping a new diver than go on a solo romp.

Added... As others mentioned the LP72 without a + marking will be a ~65CF cylinder on a standard perfect fill. That does put you at something of a disadvantage in matching range with peers that may be diving the ubiquitous AL80. Some of us do have 72s in use but most are seasoned divers and/or reserve them for less demanding dives. If you are looking to spend some $$ the HP100 is a sweet cylinder. I used one today. I'm especially fond of my HP80s but they won't give you the same bump in range.

If it's a used HP 100 rated at 3500 PSI beware that is will be a DIN only connection.

I also agree that flying a few feet above will get old real fast. For keeping visual contact between divers its a PITA unless all go up.

We need to get together some time!

Pete

 

[smorneau]

Well my resting SAC on the couch is .3 on my dive today it was .7 so I guess I'm not as bad as I thought. Using 65cf instead of 72 helped in the calulations.

 

[imwright1985]

I find my computer gives SAC rate, which I found varying a bit when i am hunting, but was shocked because my dive partner borrowed it once and his profile was higher then I tend to run and his air consumption is actually worse, yet he nags about me guzzling air. Just enjoy diving and find people you enjoy diving with and have similar bottom times

 

[smorneau]

If it's a used HP 100 rated at 3500 PSI beware that is will be a DIN only connection.

I also agree that flying a few feet above will get old real fast. For keeping visual contact between divers its a PITA unless all go up.

We need to get together some time!

Pete

Do the newer HP100's have din/yoke convertible valves?

Pete I have been hoping to get out with you guys sometime. I am hoping to be at the meeting on Thursday.

 

[Bubbletrubble]

Do the newer HP100's have din/yoke convertible valves?

The most common HP100 tank sold by shops where I live is the XS Scuba-branded one.
All of the XS Scuba Worthington X7-100s I've seen come with the Thermo Pro DIN/K convertible valves (3/4 NPS opening).
Service pressure on the these tanks is 3442 psi.
The female DIN outlet depth is 5-thread, and the yoke insert can be screwed into it for use with a yoke-configured regulator.

On the "used" tank market, you're likely to encounter the PST HP100 tanks with skinny neck opening (7/8 UNF).
As spectrum pointed out, service pressure on these tanks is 3500 psi.
The female DIN outlet depth is 7-thread, and it's too deep for the above-mentioned yoke insert to work properly.
Thus, using this particular tank valve demands a DIN-configured regulator.

 

[shagyluke]

You really shouldnt be concerned with other peeps sac rate untill you learn to gas match. I am full cave certed and am a Technical diver and I still have a high sac rate. When I started diving about 500 dives ago my sac rate was .78. Now its down a little at .68 and thats working sac rate. I have a buddy that has a .4 working sac rate so we go off of my sac rate when planning dives and gas matching. All I can say is that everyone is different and your sac will come down in time. Just have fun .

 

[Rapid Diver]

Great thread, thanks to all who have added their SAC rates.

I find a good baseline average for SAC rates is .5 (really good) to 1 CFM (Average)

Keep reporting your SAC rates and we can try to do a "Scubaboard" average

Chris

 

[SolarStorm]

One more thing I did, not sure if anyone else needs to though, to lower my SAC rate was a start a cardio program at the Gym. Lost 25 lbs (had to buy a new wetsuit) but also found I didnt work near as hard, therefor breath less. Had benefits outside of diving too.