What air level indicates your dive is done?

[mchiapetto]

I am new to diving. I read the posts about what ends your dive and most people anwered "when they are out of air". But I am curious what that means to people. So hence the poll. At what volume of air do you end your dive and start heading to the surface?

 

[Goeduck]

mchiapetto;

I am new to diving too, at least this time around, but to kinda answer your question, you have to know what kind of dive you are planning.

If it is a shallow dive, say to 40 fsw or so, you can decided on a lower pressure than if you were doing a deeper dive, say to 100fsw or so.

The main thing is that you and your buddy agree on beforehand, during your planning stage, on what the minimum pressure is to start heading up. When the first person hits that minimum pressure, you both head up. You also have to take into account the 3 to 5 minute safety stop.

I know that I am not giving you exact answers, but each person uses a different amount of air, so what is good for one person might not be enough for the other person.

It will take a few dives to come to the correct amount for you, but personally, I would like to surface with about 500lbs minimum, just in case you or your buddy gets into an OOA situation.

I hope this helps.

 

[Bob3]

Dang, you left out the whole range below 500 psi.

 

[radagalf]

Generally once someone in the group reaches 'half-air' (1500 PSI) is when we start heading into shore. Once someone is at 500 PSI we all surface (which really sucks for me, cause I'm usually at 1200 - 1900 PSI still).

When diving with just friends (above was leading a dive through the dive shop), same thing, except whoever hits 500 surfaces, and the others keep on their dive until a) they hit 500 or b) NDL limits. (We go up enoguh that we can see they've reached the surface, and then they follow our bubbles or head into shore if it is close by).

No one ever dives by themselves. If it is the last 2, once either of them have 500 they both surface.

Have fun!!!

 

[dgangi]

Personally, the amount of air that I quit my dive with depends on how deep I am. At anything lower than 50', I always like to start ascending on 700 psi. But if I am doing a shallow dive (say 30'), then I have no problem going down to 500 psi.

You always want to plan your ascent with enough air to make a safety stop. I typically plan a safety stop at 15' for 3 minutes on every dive -- 5 minutes if I feel I have been too close to the "no deco" limit of my dive computer.

Thx...Doug

 

[art.chick]

I am with those who say that there has t be more info on what type of dive before I give a particular answer. This question is near to my heart because I once dove with a new buddy who told me that he would need 500psi to ascend. I was quite impressed, as the dive was 90'. I presumed that he was a very efficient breather but asked no questions.

He did not show me his guage the whole dive, but gave me a "low on air" signal when we had been at the bottom for a predictable amount of time (about 10 minutes). We began the ascent. At 60' he gave me the OOA signal & I handed him my octo.

When we got back on the boat, I did a debriefing to find out what made him think 500psi was the magic #, & he said that was the amount he always ended with. I asked what his usual depth was. He told me 30'. BIG DIFFERENCE! Now I ask lots more questions before I presume anything.

 

[Walter]

Depends on what you mean by the end of a dive. Do you mean when do I start to ascend or when to I get out of the water?

I start my ascent and different amounts of air depending on the circumstances of the dive. I plan to leave the water with approximately 13 cubic feet of air. An AL 80 has approximately 13 cubic feet of air at 500 PSI. I rarely use an AL 80, so I rarely use 500 PSI as my exit target. The amount with which I exit varies from 250 PSI to 620 PSI depending on what tank(s) I'm using. Regardless of my pressure, I have the same volume of air. OTOH, air supply is rarely the factor which sends me to the surface.

Depending on depth and other situations, I'll begin my ascent at different amounts.

 

[tombiowami]

It depends on the dive. The main factor is:
"how much gas do my buddy and me need to ascend safely, at any point in the dive?"

Remember your buddy has YOUR backup air/gas.

Do a search on "rock bottom" for the best procedure to do this stuff.

Tommy

 

[Butch103]

it depends on the dive and whom I am diving with......I try to plan to be at the ascent line (if using one) with the first diver I am with hits 1000 lbs. I too generally have more left, but safety first...I want to enjoy the diving experience for many more years, and to sacrifice this for a matter of few more minutes of bottom time makes no sense...............:boom:

 

[redacted]

I plan to arrive at the rest stop with 500 psi. And I plan to take my time getting there. And I don't count the 13 cu ft pony.