Deep Stops Recreational Divers

[Edward3c]

Rec diving means no planned stops.

There are agencies where mandatory stops are part of core recreational training and diving. This rec v tec is a pure marketing scheme to increase income streams.

 

[Gareth J]

When I did my ERD course, then later my Trimix cause. Deep stops where taught.
I habitually did a 'deep stop', but generally I planned my stop at 32m, my gas switch depth. I found that a planned stop at the gas switch depth was advantageous. In that it allowed me to settle, and switch gears to the ascent phase. It also allowed me to double check my ascent schedule (they where all hard written tables).

I still find it very relaxing at the end of the dive to stop 'early' as part of the ascent for a minute or so, make sure I'm on plan.

Even on CCR mixed gas course we effectively did a deep stop. This was because we flushed the loop, purging helium from the loop and filling with travel gas - i.e. a switch to Nitrox. The issue with CCR is that you are off gasing helium back into the loop during the decompression phase.

There was a great presentation at one of the BSAC Diving Officer Conferences about decompression theory, I think it was given by J M Imbert (A long time ago 15 years?). Which, from what I remember, showed, that extending the shallow stop was far more beneficial than extending the deep stop. i.e. for a like for like dive. Again, from what I remember, the deep stop reduced the risk of joint hits, but shallow stops reduced the risk of neurological hits.
The great shame is I don't think the material was ever published, or not so that I could study it.

 

[RainPilot]

Deep stops never were part of any training that I’m aware of in standard recreational NDL diving.

When NAUI bought into RGBM in the early 2000's, a stop at depth was encouraged. Im looking for my old NAUI Scuba Diver manuals to check what it was exactly...

Ok, found it in the RGBM Supplement currently in use:

You may also use the NAUI Rule of Half Stops in place of the required safety stop.

• Stop half your distance to the surface for one minute.

• Then stop for two minutes at 5 msw (15 fsw).

Rule of Halves for NAUI Air, EAN32, and EAN36 Recreational Tables (Sources, 2nd Quarter 2003).

This protocol safely augments and modifies the usual 3-minute safety stop in the 5 msw (15 fsw) zone in a

manner consistent with modern analysis, experience, and deep stop validation.

This rule applies to the NAUI [USN-based] and the NAUI RGBM Recreational Dive Tables.

• For table-based no-required-decompression dives in excess of 12 msw (40 fsw), divers should halve

the distance to the surface from the dive’s deepest depth and make a 1-minute precautionary stop at

that depth, followed by a 2-minute safety stop in the 5 msw (15 fsw) zone. For example, on a dive to

30 msw (100 fsw) the diver should make a 1-minute stop at about 16 msw (50 fsw) and a 2-minute

stop at about 5 msw (15 fsw).

• On dives shallower than 12 msw (40 fsw), a standard 3-minute precautionary stop at about 5 msw

(15 fsw) should be completed.

 

[dmaziuk]

No, but it can be ignored.

It's always been off on ours, but from reading the fine manual it won't even come up unless max depth is down to 30+ m range. Which you rarely do on a typical reef dive. However the computer is old enough to call them "bad" deep stops rather than "good" PDISesses.

 

[seeker242]

Stops were starting at half of my depth. For a 100 feet / 30 meter dive the first stop would be at 50 feet / 30 meter. There is 30 seconds for the stop and 30 seconds to go to the next stop.(50,40,30,20,10 feet / 15,11,9,6,3 meter)

Which is fundamentals min deco as taught currently. Which are not deep stops but merely a slowed ascent rate from 30’/min to 10’/ min.

 

[Storker]

10”/ min.

That seems awfully slow to me. While I might try to approach that ascent rate during my last meter or so below the surface, I don't think it's very appropriate any deeper than that.

 

[seeker242]

That seems awfully slow to me. While I might try to approach that ascent rate during my last meter or so below the surface, I don't think it's very appropriate any deeper than that.

Would it make sense to go 30'/min to the last meter and then just surface, never stopping anywhere?

 

[Storker]

Would it make sense to go 30'/min to the last meter and then just surface, never stopping anywhere?

30'/min (10m/min) is quite a bit faster than 25"/min (0.625 m/min). After my safety stop, I prefer an ascent rate somewhere between those two.

 

[seeker242]

After my safety stop, I prefer an ascent rate

Makes sense. However with GUE, there is no safety stop anywhere. There is just 10’/min direct to the surface instead of a SS. It’s definitely slow, which is why it’s broken up into 30 second segments. In practice it’s actually 20’/min, with a 0.30 stop every 10 feet, which is considered equivalent to 10’/min.

 

[Storker]

ith GUE, there is no safety stop anywhere.

My computer gets seriously p***ed off at me if I skip the safety stop. So I indulge it. I figure it can't hurt to take the last 6 or so meters real slow, and I've had some experiences indicating that it may be a good idea to take the last 6 or so meters real slow.