Ok, so this popped in my head the other day. Back when i took my AOW our instructor had us do safety stops where what ever depth you were at divide by half and then do 1 minute stops from there and every 10 feet up. So if we dove down to 80feet our first stop would be at 40ft for a minute, then 30ft for a minute, 20ft for a minute and lastly 10ft for a minute and then surface.
Is there a benefit to doing it this way over ascending from 80ft, or whatever depth you were at, to 15ft for 3-5 minutes? I didnt think to ask why back when i took the course.
Years before anybody was really talking about deep stops in recreational diving, I made up my own little rules when I was a Divemaster.
What I demanded was that everyone stop at 30 feet, check their air and show me their gage.
I never disclosed the real purpose, but it was EXTREMELY effective in preventing uncontrolled ascents. I taught it to some other DM's and at first they thought it was stupid, but after they tried it a few times they also benefited from much more serene ascents.... no more chasing customers or trying to dart out and snatch the fin tip of a buoyant clown as he floats past the group.
I found that if I could get the people to try to totally STOP their ascent at 30 feet, many of them would be successful, but a good percentage would not. HOWEVER, since they were really TRYING to stop at 30 feet, they would almost always get their sXXX together by the time they floated up to 15 feet. Very few would totally lose it and blow all the way to the surface. Demanding a stop around 30 feet was EXTREMELY effective in getting "tourist" type divers from endangering me and themselves via run away ascents. So there is a VERY practical reason to direct people to STOP well below 10-15 feet.
Now we have more information about the idea of deep stops, I've noticed big improvements in how I feel when doing a deep stop. On no-deco dives to even 130, I will stop at around 50 feet, chill for a minute or two.. generally wait there until my heart rate is really relaxed and then slowly move on up toward 20 feet, where I will do another short stop.
I don't follow 1 minute at each 10 feet, but that is perfectly fine way to do an ascent; I just come up real slow to 20 feet over a period of maybe 2 minutes (which is of course close to 1 minute stop at each 10 ft increment). When diving really hard, doing 4-5-6 dives per day to or past the recreational (no-deco) limits, I quite often got "pole spear elbow" (I was spearfishing). A pretty painful condition in the one elbow that lasted for a while on the boat, often for an hour.
After I started doing the deep stops, no more pole spear elbow.. the difference was pretty dramatic.