Safety stop immediately after surfacing

[MXGratefulDiver]

Fantastic thread, i was reading about safety stops and the diver was saying that when you are deeper then 40 ft you go half and stop for 1 min then do 2 at 15ft thats your 3 min safety. I was told you always do its 3 min at 15 ft no matter how deep you are. So if you dive 60ft you stop at 30 fot 1 and go to 15 for 3min.

The notion of doing deep stops is fairly new to recreational dive instruction, and is not currently taught by all agencies. The one I teach for (NAUI) adopted the notion a few years ago for deep dives, and has since recommended it for all dives.

The thinking is, in part, because the tissues in your body offgas at different rates, and stopping at half your deepest depth for a minute gives the fastest-offgassing tissues (your blood, brain and nerves) a chance to "catch up" before putting them in a situation where they can offgas even faster. The other part of the thinking is that a lot of recreational divers have increasing difficulty holding their ascent rate steady as they get closer to the surface, and tend to speed up as they ascend. Stopping for a minute at half your deepest depth gives you a chance to "reset" your ascent rate control and therefore a better shot at keeping your ascent rate within what are considered acceptable limits.

Like a lot of rules for recreational diving, it's more a precautionary measure than something that, if you don't do it, will lead to an injury. For practical purposes, probably the best result of this stop will be to help you reduce the amount of fatigue you feel after a dive by helping you control your offgassing rate during your ascent.

... Bob (Grateful Diver)

 

[Brian Sharpe]

Read Deco for Divers by Mark Powell. While no cause & effect relationship between "silent bubbles" and DCS has been made there is a significant reduction in these when a deep stop is added to a safety stop.

I've adopted the practice and, considering we enjoy being submerged, can't imagine why it wouldn't be a widely adopted practice.

 

[DaleC]

As I have learned more about DCS and sub clinical DCS I have changed the way I do SS's. To me the 3 minutes at 15' is important but the ascent from 15' to surface is just as important too. I take that very slow (perhaps a minute or more). I have found that this plays a role in my "freshness" for repetitive dives or the drive home.
I have also gotten away from ascending to orient, regroup etc... I try not to surface during a dive unless I have to (for the above reason).

 

[DCBC]

To me the 3 minutes at 15' is important but the ascent from 15' to surface is just as important too.

Right on Dale. DCIEM uses an maximum ascent rate of 15 fpm near the surface. In saturation diving it's as little as 0.5 from 30' and 1 fpm from depth with stops every 10'. It makes a long ascent from 1300'.

 

[MXGratefulDiver]

As I have learned more about DCS and sub clinical DCS I have changed the way I do SS's. To me the 3 minutes at 15' is important but the ascent from 15' to surface is just as important too. I take that very slow (perhaps a minute or more). I have found that this plays a role in my "freshness" for repetitive dives or the drive home.
I have also gotten away from ascending to orient, regroup etc... I try not to surface during a dive unless I have to (for the above reason).

That part bears emphasis ... I've seen way too many divers religiously watch their timers to clock that 3 minutes, only to be on the surface a few seconds after they've given each other the signal that it's time to ascend from their safety stop.

To my concern, coming up slowly from that last 15 feet is probably more beneficial than the three minutes you spent at that depth ... it should take NO LESS than 30 seconds from safety stop to surface. Until you get used to it, it does seem really slow ...

... Bob (Grateful Diver)

 

[MauiScubaSteve]

Refresh my memory again, how deep are these usually done from? And how long is the typical OW dive 2 or 3?

:shocked2:

A Suunto will ask you to do a SS after 5 min at 15 ft from what I've seen, and the OP did not put any time/depth restraints on the conversation to my knowledge.

As I'm sure you know, dive #2 is max depth 40' and the dive sites I have used for said dive have the feature attraction and planned destination of the tour portion of the dive at 40', as long as you remain neutrally buoyant over the turtle cleaning station and don't go kneel in the sand.

Similarly sure you know, dive #3 has a max depth of 60', but most shore locations I have used do not offer much of interest/reach deeper than 50'. Dive #3 at Molokini it is the plan to go to ~60' and again control the depth with buoyancy and not knees.

Once again sure you know, CESA is typically done from 20-30' depths, and as I see it the last one of the sequence I proposed is very similar in nature to blowing the 15'/3 min SS.

Using 100 cft's for most hoovers and only 63's for sippers, my goal is more than 40 minutes dive time on every OW training dive. We dive until someone in the class reaches minimum ascent pressure. Letting my computer clear the SS count down even when my students are diving a tables profile is leading by example and they are involved in discussions to that end.

The OP claims to be a beginning diver so it would seem natural to talk in terms of the nitrogen load of beginning divers and dives.

 

[pedo]

That part bears emphasis ... I've seen way too many divers religiously watch their timers to clock that 3 minutes, only to be on the surface a few seconds after they've given each other the signal that it's time to ascend from their safety stop.

To my concern, coming up slowly from that last 15 feet is probably more beneficial than the three minutes you spent at that depth ... it should take NO LESS than 30 seconds from safety stop to surface. Until you get used to it, it does seem really slow ...

... Bob (Grateful Diver)

It's really slow even when you're used to it but what'cha gonna do?

 

[RJP]

A Suunto will ask you to do a SS after 5 min at 15 ft from what I've seen...

Actually, a Suunto will COUNT DOWN a safety stop if you DO ONE...but it will not require one (ie won't beep, flash, lock you out, or penalize you on subsequent dives.)

 

[MXGratefulDiver]

It's really slow even when you're used to it but what'cha gonna do?

It's all relative ... on our tech dives we take 5 minutes for the last 20 feet.

Once you get used to that, 30 feet per minute seems blazingly quick ...

... Bob (Grateful Diver)

 

[MauiScubaSteve]

Are you sure all Suunto's will not penalize you for skipping any SS; I have guided for more than one charter using Gecko's for customers, have used my Viper for more than 7 years and I think some skipped SS's might just reduce the time of next dive with a limited SI compared to the diver that didn't skip the SS. I'm almost certain fast ascents will cause Suunto penalties.