Is there any scientific evidence that safety stop decrease DCS risks?

[boulderjohn]

I stole this from @RayfromTX who stole it from @MaxBottomtime. It seemed appropriate to the discussion.

The original is from Richard Pyle--and it was much more elaborate.

 

[MaxBottomtime]

I stole it from Thalassamania.

 

[Kharon]

depends on their definition of "gradually" and what you're doing. If you're doing square profile, ocean diving, i.e. on a wreck with an upline, and there is nothing to see between the bottom and the hang line, then go up at 30fpm ish and chill out. If you're doing a shore dive and there's fun stuff to look at, then just go up at whatever rate you want to to keep looking at the pretty fish

Thanks. Amost all my dives are from shore and I do like to slowly prowl back up the slope. Once on a boat dive I had a DM tell me that I should head directly up to safety stop depth and then head back to the boat. Glad to hear I don't have to do that.

 

[bada3003]

I thought it was advised to go straight up from depth at a proper ascent rate to the safety stop depth. This is to prevent further ongassing of the slow compartments. What say you tbone1004?

If you're doing NDL dives, yes, that's roughly consistent with what research by Doolette and others have shown. Instead of relying on Internet wisdom, it's best to read the literature yourself and draw your own conclusions. I'm a research scientist and what I've outlined is just my personal practice to keep myself safe based on the evidence I've disseminated. That includes personal wisdom from others which may be anecdotal (hence it is what it is) but sometimes, collectively, they paint a consistent picture. One example is my trimix instructor who is in his 60s and who has managed to stay alive over many decades doing very challenging dives. I don't agree with everything he says but he's been following deco profiles consistent with what NEDU research has shown. The importance of slowly exiting from 10-15 feet, if conditions allow, is a practice that I've come to follow through this process of learning and my personal empirical experience. Take it FWIW, be conservative and stay safe.