Split from A&I Yukon thread: Gas Rules in OW Solo Dives

[redacted]

If we all planned to surface with all the gas we started with, we would probably all be safer. And we could all do 30 mph on the interstate while we are in this "safer" mode.

 

[Jax]

Oh, stop with the superlatives! "All the gas" indeed!

We are talking about some good, solid, conservative recommendations for solo divers. You don't have to follow them, nor is there any reason to make fun of them.

 

[Blackwood]

Oh, stop with the superlatives! "All the gas" indeed!

We are talking about some good, solid, conservative recommendations for solo divers. You don't have to follow them, nor is there any reason to make fun of them.

But why 1/3? Why not 1/4 out 1/4 up, 1/2 reserve? I imagine that was awap's point.

The problem with the application of thirds is that the assumptions behind it don't necessarily apply to openwater profiles, so it's bound to be questioned (or have fun poked at it).

 

[Jax]

But why 1/3? Why not 1/4 out 1/4 up, 1/2 reserve? I imagine that was awap's point.

The problem with the application of thirds is that the assumptions behind it don't necessarily apply to openwater profiles, so it's bound to be questioned (or have fun poked at it).

1/4 and 1/4 leaving 1/2 researve doesn't make any sense. Rule of thirds does.

 

[ScubaSteve]

1/4 and 1/4 leaving 1/2 researve doesn't make any sense. Rule of thirds does.

Rule of thirds makes no more sense than .25, .25, .50 for an open water no deco dive. I think the point is that if you are going to try to simplify a gas plan, it might as well make sense for the environment and the dive (the plan).

 

[Thalassamania]

I can see no basis for a rule of thirds. I don't mean to ridicule it, but without some rationalization, it's kinda hard not to, it being so extreme.

 

[Puffer Fish]

I can see no basis for a rule of thirds. I don't mean to ridicule it, but without some rationalization, it's kinda hard not to, it being so extreme.

Sure would make for a short dive to 100 ft, on an al80.

Would not take much of a time lapse to run out of air. In the last few years I have seen a fair number of divers in the 100 ft depth range that get forgetful narced... where they don't look at gauges. Put a camera in their hands and one has a very bad mix.

I also know photographers that are that way in shallow water.

On the flip side, I have not had an insta-buddy in the last 10 years ever check how much gas I had, so I'm not sure having a buddy would have done any good.

I would be very happy if OOA was never the cause of any diver deaths

I did the big "O" this year carrying 183 cubic ft of gas, but there were people diving that had AL80's down with me at 140 ft.don't know if this is just the nature of people today, or if the training is missing something.

However, I have had to physically remove 3 people this year from the bottom to prevent them from running out of air.

 

[Tortuga68]

Apologies for being responsible for the hijack

whatever happend to 1/3 1/3 1/3 on the planning? they not teaching that to you guys now?

Not for open water diving

Why on earth would that be at about 1000psi? Especially if you're diving solo and don't have to have gas for a buddy?
When did the rule of thirds become applicable to a no ceiling, open water diver?

I specifically said 500psi would be fine for a solo dive. 1000psi or 70 bar would be to get you and your buddy safely up from 100' that's a pretty common low gas mark for deep dives not sure what's so amazing about it to you

1000psi turn pressure is not rule of thirds

 

[donhealy]

Sure would make for a short dive to 100 ft, on an al80.

Would not take much of a time lapse to run out of air. In the last few years I have seen a fair number of divers in the 100 ft depth range that get forgetful narced... where they don't look at gauges. Put a camera in their hands and one has a very bad mix.

I also know photographers that are that way in shallow water.

On the flip side, I have not had an insta-buddy in the last 10 years ever check how much gas I had, so I'm not sure having a buddy would have done any good.

I would be very happy if OOA was never the cause of any diver deaths

I did the big "O" this year carrying 183 cubic ft of gas, but there were people diving that had AL80's down with me at 140 ft.don't know if this is just the nature of people today, or if the training is missing something.

However, I have had to physically remove 3 people this year from the bottom to prevent them from running out of air.

On the flip side, I have not had an insta-buddy in the last 10 years ever check how much gas I had, so I'm not sure having a buddy would have done any good.

Sorry to hear that. Should buddy up with me. I am guilty of asking at 3 times a dive.

Don

 

[Thalassamania]

Apologies for being responsible for the hijack

Not for open water diving

I specifically said 500psi would be fine for a solo dive. 1000psi or 70 bar would be to get you and your buddy safely up from 100' that's a pretty common low gas mark for deep dives not sure what's so amazing about it to you

1000psi turn pressure is not rule of thirds

I believe we are having two separate conversations, I was talking about the way SDI suggests.

Cool the replies seem to be slowing down!

When I was in my wreck diving class at the Yukon Saturday morning, our instructor, who has over 400 dives at the Yukon, religiously sticks to the 1/3 1/3 1/3 rule. He has a 72 HP steel tank, and came up with about 900 PSI with a dive time of about 25 minutes. So he came up with about 1/3 in reserve.

One of our other divers with a 120 HP came up with about the same amount, less than 1000 PSI. I also have a 120 HP and came up with 1600 PSI. But because we were doing this as a group, we all came up together. I showed a max depth of 87 feet.

Please ask your instructor for a specific reason why, I simply can not think of one.