Do you turn the air off or leave it on after setting up on a tank?

[L13]

I assumed his reference to the half hour before his shore dive meant while the rig is sitting on a bench or the tailgate of his vehicle while he gets ready. That's what I do, and for the same reason he mentioned. I look at the gauge to see my pressure after setting it up, leave it on while I don my drysuit, discuss the dive plan with my buddy, eat an energy bar, etc., and then look at it again before getting into the rig to see if the needle moved.

I do the same thing, but with the valve off. Any slow leaks show much more dramatically that way. (except for my sherwood 1st, the design of the reg has an intentional slow leak).

 

[Bob DBF]

I do the same thing, but with the valve off. Any slow leaks show much more dramatically that way. (except for my sherwood 1st, the design of the reg has an intentional slow leak).

It's hard to call that a real leak, since it would take well over 24 hours to lose a cubic foot of gas (32# in an HP 100), doubt that one would notice it while waiting to dive. 13-17cc/min isn't a lot, although quite noticeable on a dive as it is out of the ordinary for other regs.

 

[L13]

It's hard to call that a real leak, since it would take well over 24 hours to lose a cubic foot of gas (32# in an HP 100), doubt that one would notice it while waiting to dive. 13-17cc/min isn't a lot, although quite noticeable on a dive as it is out of the ordinary for other regs.

It is noticeable if you turn the valve off after pressurizing, as I stated.

The internal volume of the valve/reg/hose is small enough for 13cc/min to produce a noticeable drop in pressure fairly quick.

 

[Dark Wolf]

I do the same thing, but with the valve off. Any slow leaks show much more dramatically that way. (except for my sherwood 1st, the design of the reg has an intentional slow leak).

I do the same. Pressurize everything, valves off, check SPG. Check again directly pre dive, turn valves on.

It's hard to call that a real leak, since it would take well over 24 hours to lose a cubic foot of gas (32# in an HP 100), doubt that one would notice it while waiting to dive. 13-17cc/min isn't a lot, although quite noticeable on a dive as it is out of the ordinary for other regs.

Agreed. And I don't get excited about it. But it gives me a rough baseline to compare with.

DW

 

[Polarorbit]

Recreational diving of double tanks is not uncommon in some parts of the world, such as the UK and the US west coast. I have done a bit here in the Southeast.

Fair enough. Doesn’t change the fact that you should be close to neutral if properly weighted.

 

[Polarorbit]

Snorkels live in the box unless needed for a very long surface swim

60-70 lbs, let's see:
Steel 100 = ~35
BP/W = ~10
Lead = ~15-20
Wetsuit = ~20
Regs = ~4
Fins = ~4
That math right there puts an average cold water diver at 90+ lbs and that is only with a single tank. Warm tropic diving is much easier since you don't need the thick neoprene or drysuit and associated lead. I'll forgive you this time.

I was just thinking of the gear on your back since the comment was about being unable to stand up after falling on your face. I acknowledge you very well may have more than 60 lbs of gear total. I dive cold and dry so I get it. I should have been more precise.

 

[Boarderguy]

I was just thinking of the gear on your back since the comment was about being unable to stand up after falling on your face. I acknowledge you very well may have more than 60 lbs of gear total. I dive cold and dry so I get it. I should have been more precise.

I think I'm still close to 60 or 70 on my back. 100 or 119, 13 pony back mounted, 14 lbs lead, sta, AL plate, pony mount, reg sets x2... it would be a struggle to get upright after being toppled. If turtle then would be even worse. Air on and all 3 regs breathed and wing inflated before I even look at the water.

 

[Polarorbit]

Air on and all 3 regs breathed and wing inflated before I even look at the water.

I’m not questioning the wisdom of having a routine to insure you’re ready prior to entry. I just don’t see the crisis, if you’re properly weighted. It might be embarrassing but you should be able to reach the surface and get positive.

 

[Beau Holden]

Fair enough. Doesn’t change the fact that you should be close to neutral if properly weighted.

you very well may have more than 60 lbs of gear total.

I also dive dry, with LP85 or HP80 doubles with SS BP and a Dive Rite Rec wing un-bungied. Well over 60lbs. If I take the giant leap off the boat with no gas in the wing and gas off, I had better be equalizing real fast and hopefully have a shallow hard bottom and be quick about getting some gas turned on. This would not make for a good weekend,

As a matter of fact, I think I am going to try it next time no gas in wing, but gas on and see how long it takes me to get stopped and neutral. Should be an interesting ride

 

[Polarorbit]

I also dive dry, with LP85 or HP80 doubles with SS BP and a Dive Rite Rec wing un-bungied. Well over 60lbs. If I take the giant leap off the boat with no gas in the wing and gas off, I had better be equalizing real fast and hopefully have a shallow hard bottom and be quick about getting some gas turned on. This would not make for a good weekend,

As a matter of fact, I think I am going to try it next time no gas in wing, but gas on and see how long it takes me to get stopped and neutral. Should be an interesting ride

Why would you expect to plummet into the depths? You shouldn’t be -60 lbs buoyant. Your LP85 and BPW are probably around -15 lbs buoyant and you have just enough lead to counter the positive buoyancy of your drysuit. You should only be slightly negative, unless your drysuit floods. With double HP80s you just need around 12 lbs less lead and should still be close to neutral.