Safe Ascent

[DCBC]

How fast do you ascend and what are the variables? How do you monitor your ascent rate?

[Kevin Carlisle]

I like to go slow. Not always possible due to the high flow spring systems I dive. When I have a place where I do ascend faster then I should, ( fissures, ect. ) once clear I will usually give myself a one or two minute window for a safety stop. Just a peace of mind type thing. I use my computer some but I know the profiles of the places I dive. If the computer died I could tell you my depth at most placse I go.

[TSandM]

On a recreational dive, I do 30 fpm to half my average depth (or the depth I begin my ascent from, whichever is deeper), and then 10 fpm to the surface. I do that by leaving my current depth at "x" minutes and not leaving the next depth until "x+1". That may require a short period of stop, if my actual ascent rate has been faster than the goal. (For example, I leave 30 feet at 3 minutes and arrive at 20 at 3:30, then I stay there until 4:00.)

[vladimir]

I watch my computers. My Suunto has a maximum rate of 10 meters per minute built in, and my Uwatec has a variable rate that is close enough that i never notice the difference. I like the indicator on the Uwatec better--it displays your ascent as a percentage of the maximum rate. I generally ascend much slower than my computers require, especially during the last 5 meters.

[Blackwood]

What Lynne said.

30fpm deep, 10fpm average shallow (where I generally move at 20fpm, with 30 second stops).

[gcbryan]

If you're taking about a minimum safe ascent I would do what many of the others are doing...30 fpm/deep stop/10fpm but unless it was a wreck and I was coming up an anchor line and actually needed to do a minimum ascent I would do more from 30 fsw to the surface.

As far as my normal shore dive profile it would be much more from 30 fsw to the surface...usually around 15 minutes if there is plenty to look at. I would prefer to hit my deepest depth very early in the dive, have most of the dive be a slow decompression in effect (less time spent in the middle depths connecting the deeper and shallower portions) and then the longer optional time spent at 30 fsw and above.

[muddiver]

I still do the 30' per min per the USN. All of my computers have the same ascent rate programed in. Some times I even stop at 20' for :03 to :05.

[boulderjohn]

This DAN article might be interesting:

DAN Divers Alert Network

[TSandM]

It's an interesting paper, but I wonder where they come up with the idea that it is KNOWN that the spinal cord has a 12.5 minute halftime? As far as I know, the only studies that attempted to measure tissue tensions in real time were done a long time ago by the Navy, and those data are not generally available. And I don't know whether they measured washout.

[Michael_Lambert]

Recreational I ascend at 30 FPM till the shallows then tend to hang out a bit more 1 min @ 30, 20 and 10. I watch my computer and BT for my accent rates.