Better to safety stop at 10 or 20 if...

[M DeM]

Those are the only choices.

I just got the Perdix dive computer and the two options to set the safety stop are at 20’ or 10’.

I usually stop at 15’ so it’s kind of a moot point but I was wondering if you can’t stop at 15’ for some reason, is it safer to stop deeper or shallower?

(I don’t know, say a whale was in your way between 30’ and 4’. I know whales are taller than 26’, but this is a skinny hypothetical whale.)

And if you have thoughts on which is a better setting, do let me know.

 

[Got2Go]

I have mine set to 10. But I vary the actual stop depth depending on dive conditions, my condition, and other factors.

I might spend most of the stop somewhere between 20-10, but the last 5 feet I ascend veereee slowleeee...

 

[shurite7]

Ten feet is the ideal stop. However, conditions, such as high waves, are not always conducive for this. Therefore, the twenty foot choice is a better option. The fifteen foot stop is a simple compromise and usually works well. For some people, fifteen feet is easier to maintain buoyancy than ten feet.

 

[decompression]

Set it for 10 and actually stop where conditions are best.......if at rec depths/time it’s not going to make much difference.

 

[Bratface]

Mine is set at 10 but I usually start my safety stop at 20 feet and adjust for conditions.

 

[Snoweman]

I've never checked where mine is set, but the timer works at 15'.

 

[Bob DBF]

My computer likes to start at 15' and resets somewhere below 20'. If one is not deco diving, the depth need not be precise, and technically the stop need not be made. I feel it is a good idea to make the stop and hold the stop as precisely as possible in the event that I do incur a deco obligation and have to make an actual deco stop(s).


Bob

 

[Saltyhawg]

My computer starts the safety stop countdown at 19 feet. I usually do mine at about 15' My computer is very conservative so i don't worry to much as long as I'm between 17-10(hang with the group) unless I'm closer to NDL than normal.

 

[Blasto]

If you were trying to get to the theoretical optimum, it would be neither. You'd stop at the appropriate depth to minimize your peak supersaturation stress as you're eliminating your nitrogen. This will depend on your dive profile.

In practice the closest way to that is to use ZHL (Buhlmann) set to very low GF (both high and low) and use its stops instead of the safety stop. It will be very similar to the safety stop you would normally do anyway, so no real difference.

 

[boulderjohn]

Neither.

Stop at the appropriate depth to minimize your peak supersaturation stress as you're eliminating your nitrogen. This will depend on your dive profile. The best way is to use ZHL with low GF. Current science indicates the optimum stop distribution to be at GF.low=GF.high.

I have no idea what you are talking about here.

What current science are you talking about regarding depths of safety stops? Can you provide a link?