What ascent speed(s) do you use after gas switching on ascent?

[thetechnicaldiver]

Interested to hear everyone's take on ascent speeds after, switching to say 50%, or maybe a deeper switch. Commonly 3m/min to 6m, then 1m/min, but also potentially 6m/min and then 3m/min until 6m to account for the change in relative pressure as you shallow up.. What were you taught, what do you do?

Interested to hear different approaches and the reasons why. Thanks in advance.

 

[tbone1004]

Most of my diving is cave diving, so we don't always have the ability to make quick ish ascents since there is a big rock slab over your head.

In OW, I was trained, and will go about 10m/min up until the first gas switch which coincides with the first deco stops. Once you're there, the stops are spaced about 3m apart, so I will typically go about 6m/min up to the next stop. In the caves, my final stop is at 3m, and I will usually make a 1-2m/min ascent from there. In the ocean, my final stop may be at 10m, and with that it's all calculated based on surface conditions. I.e. do I stay at 10m for an extra 5 minutes so my ceiling is higher and I can make a more rapid ascent if the surface conditions are rough? If the surface conditions are calm, then I'll make a 3m final stop and take my time getting up, but it's all evaluated once I get to that 10m stop based on the surface conditions

 

[boulderjohn]

Commonly 3m/min to 6m, then 1m/min, but also potentially 6m/min and then 3m/min until 6m to account for the change in relative pressure as you shallow up..

This is common? I have never encountered it.

I know some people who do an extremely slow ascents after their final stop (usually at 3 m), but everyone I dive with does 10m/min throughout the ascent. That is usually the default ascent rate on computer programs and dive computers.

 

[PfcAJ]

10fpm.

 

[Blasto]

In the sea, 3 fpm from 21±1 ft last stop to 10-12 ft depending on typical local boat draft. No stop at 10, better to suffer less perfect deco than get cut up by a sailboat - they're silent, fast, and their keels go deep.

Then 60 fpm to 0.
In a boat-free inland area, reel up all the way at 3 fpm instead.

 

[RainPilot]

10m/min then 3m/min. As slow as practical from 6m and up.

 

[The Chairman]

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[DevonDiver]

- 9m/min to the switch.
- 3m/min between stops.
- 1m/min* last stop to the surface

(* in many cases I'll use the Shearwater GF99 function to mentally set a surfacing GF even lower (5-10 less) than set for the dive - this gives a "mini-curve" from the last stop to the surface. It's dependent on surface water conditions, obviously).

 

[Kevrumbo]

Interested to hear everyone's take on ascent speeds after, switching to say 50%, or maybe a deeper switch. Commonly 3m/min to 6m, then 1m/min, but also potentially 6m/min and then 3m/min until 6m to account for the change in relative pressure as you shallow up.. What were you taught, what do you do?

Interested to hear different approaches and the reasons why. Thanks in advance.

For a deeper Open Circuit 21/35 Trimix deco gas switch, a 6m/min ascent rate is fine in between scheduled stops as prescribed by your particular deco software plan algorithm (that's a minimum 15 seconds hold or greater as prescribed by your deco software profile at every 3 meters delta, and then approx 15 seconds to ascend & move every 3 meters transit up) starting at 57 meters, and for every 3 meter interval up going all the way to the next deco gas switch at 36 meters (Triox deco gas 35/25).

After that, a 3m/min ascent rate or a minimal 30 second hold or greater as again prescribed by your deco software profile at every 3 meters delta, and approx 30 seconds to transit every 3 meters up is good for the last intermediate deco gas switch and scheduled profiles starting at 21 meters (Triox 50/25 or Nitrox50), and the final deco switch to Oxygen at 6 meters. From 6 meters to surface on Oxygen, an easy slow 1m/min to 0.5m/min ascent rate of six to twelve minutes duration for the final transit to the surface, taking care to monitor for decompression stress signs of the "niggles" -to outright acute symptoms of essential DCS. . .

 

[lermontov]

10m/min then 3m/min. As slow as practical from 6m and up.

same and still breathing on it until i get on boat -and if its the last dive of the day and Ive paid for it i stay on it for a while longer