Poll: At what tank pressure do you plan to end your dive and ascend w/ safety stop

[TSandM]

Bob's article sums it up. For every dive, you need a strategy for how you are going to execute that dive, and that includes how you are going to apportion your breathing gas supply for the descent, bottom time, and ascent portions of the dive. This will differ, depending on whether you are shore diving or boat diving, and whether the boat is anchored or live. And one must always remind mindful that a reserve sufficient to get you and your buddy safely to the surface must always be maintained, and that reserve will be far larger for deeper dives.

 

[nolatom]

Free ascent, mid-level current? You need more air.

Nice anchor line? Less air.

 

[NavyGuyAN]

I have my computer to go off at 700 psi to kinda give me a heads-up and I'm usually on the surface with about 450-500 psi... I however tested my upper limits and recently did a 62 min dive at 75ft. on an aluminum 80: EAX 34 and surfaced/ended with 190 psi. I would never advise anyone to suface with so little air, in fact I would definitely say you should not.

 

[nimoh]

I have my computer to go off at 700 psi to kinda give me a heads-up and I'm usually on the surface with about 450-500 psi... I however tested my upper limits and recently did a 62 min dive at 75ft. on an aluminum 80: EAX 34 and surfaced/ended with 190 psi. I would never advise anyone to suface with so little air, in fact I would definitely say you should not.

I assume you met your decompression obligation before surfacing at 190psi?

I agree with you that this shouldn't be done, but will also add that it shouldn't be posted in the basic scuba discussions section either

 

[ajduplessis]

All recreational dives surface with 50bar (around 700psi), everything else is 3rds.

 

[z28lt1]

Does anyone use their AI computer for the time-to-ascent pressure? On my computer I set a return to surface pressure (personally set to 600 PSI when told to be back at 500), and it calculates air time remaining (based upon last 60 seconds of SAC) until I have to begin to surface, calculating for an ascent rate of 30 fpm, any required deco stops (none for me, hopefully) and a 15/3 safety stop.

Obviously if my buddy needs some air on the way up, I won't return with the 600 planned, but that's what the 600 extra is for. Is there a reason to not use this method, as an addition to the dive plan? Obviously I can't use that as a turn pressure or a dive planning tool, but when the dive plan is xxx time OR xxx pressure, I can let the computer figure out the later.

 

[Scuba_Noob]

My typical dive plan is to do my safety stop at 750 psi so that I can surface with 500 psi or over. If I want to stay down at 15 feet to check out the sights, that's fine too, as long as I surface with more than 300 or 400 psi.

In order to do my safety stop at 750 psi, I'll start ascending slowly at around 1000psi. This works out well for most dives at recreational depths, but I might ascend at less pressure if I'm doing a shallow dive or with more pressure for a deeper dive.

If my buddy chugs air at a greater rate than I do, we'll follow his pressure gauge for the same plan.

 

[scubamarketing]

I used to be a 500psi guy, but one of the best things I learned from my GUE Fundies course was about actually calculating this number. It really depends on tank, buddy, depth, dive profile and consumption rates. It's still a relatively new concept for me, so my math isn't as fast as I want it to be, but intend to actually calculate how much air is needed to safely surface.

 

[TMHeimer]

Variables (current, line/no line, etc.) aside, I was taught in Deep course to begin ascent to safety stop allowing 100 PSI for every 10' of depth. So at 70' I start up with 700 PSI. At 100' with 1,000. And use the rule of thirds.

 

[Ordie]

I always use the rule of thirds. 1/3 of my air out, 1/3 back. you will always have enough air incase of an emergency.