Question about Safety Stop on shalllow dives?

[mohave_steve]

Hello All,

I had the oportunity to dive the rapids below the Hoover Dam on Saturday and a question came up after our second dive. The last 15-20 minutes of the dive were spent at a depth of 17-23 feet. I have been of the opinion that regardless of dive depth a safety stop is allways a good practice. On Saturday when my air dictated that I end my dive I headed for 15' for my safety stop.... Well I started to but when I looked at my SPG I was at 18' and it seemed quite pointless to ascend 3' for a safety stop.

Is it a safe practice to skip the safety stop on dives where the last 10 minutes or more are spent at depths of less than 20-25'?

 

[SteveAD]

The entire dive is in effect a slightly deep safety stop.

 

[robertarak]

OK, this comes from a newbie, so take it for what it's worth.
I think part of the reason for a safety stop on every dive is air/time management skills, buoyancy skills and just repetitive practice. There is a difference between 25’ and 15’, but I will leave that to others to debate. I (just me personally) would do a safety stop. If nothing else it is a good habit.
Now that said, I have done swimming safety stops. I made sure my depth held at exactly 15” feet, but slowly swam towards shore for 3 min. before surfacing.

 

[Guba]

Ditto what Stevead said. And Robertarak is correct, too, in my opinion (FWIW). Shallow dives are, in fact, rolling safety stops. Shallow depth equals low nitrogen load. However, I understand that it's valuable to set good dive habits, and if that means timing out three minutes at 15 feet, then by all means go ahead and establish the habit.
One point to note...regardless of the absence of a heavy nitrogen load, that last fifteen feet still requires a slow ascent. I've seen folks on shallow dives blow to the surface like a Polaris missile as if air expansion wasn't an issue. They seem to have forgotten that DCS and air embolisms are not one and the same medical issues.

 

[Thalassamania]

If your entire dive was shallower than 27 feet (or is it 24 feet?) then, from a decompression perspective, a precautionary stop is a waste of time since you can be fully saturated (e.g. 24 hours, or more, at that depth) and come directly to the surface at a normal ascent rate.

 

[WVDiver]

There is no magic in the number 15. A safety stop can be at 20' or 10' as well. The point is that you are off gasing because your depth is shallow enough to allow nitrogen to come out of solution at a safe rate.

I.D.E.A. used to teach a 10' safety stop and may still I'm not sure. Actually mine and alot of other dive computers begin there automatic count downs when your ascent reaches 20'.

 

[Damselfish]

There's nothing magic about exactly 15ft. I know Suunto computers define safety stop as between 10-20feet, and I suspect others are similar.

There's also nothing magic about 3 minutes. You can spend longer, and might want to in some cases. Some people also do "deep stops" - you might want to search on that.

I believe when safety stops started to be recommended, the original recommendation was 10ft, but later 15 became common simply because it's easier to hold for many people.

I think part of the reason for a safety stop on every dive is air/time management skills, buoyancy skills and just repetitive practice.

practice is definitely not a bad thing, but the main reason for the safety stop is offgassing.

 

[robertarak]

practice is definitely not a bad thing, but the main reason for the safety stop is offgassing.

Very true. What I mean is that there are many dives (shallow shore dives) that do not require a safety stop for offgassing, but would for just good pratice. At least at my stage of the game, there is never too much practice, skill building or good habit building.

Again, I'm just a newbie trying to develop good skills and habits.

 

[shurite7]

If you want to practice a safety stop after conducting a shallow dive, as described above, do it at 10'.

I've read 10' is an ideal depth for a safety stop. The problem with a shallow stop is sea state or surface conditions, not withstanding buoyancy control.

 

[Charlie99]

Obviously, a 3 min 15' safety stop does little good for you when you have been in the 17-23' range for the last 15 minutes. Either skip it, or do in the 8-10' range.