Well they didn't train us this way.

[BlueTrin]

Well, I didn't mean there doesn't need to be a set of rules, just that it is very difficult to provide a set that covers every possible scenario in detail. You are certainly on the right track - thinking it through, asking questions, and continuing to learn. I applaud you. (I think in this activity, we ALL continue to learn, as long as we are open to it.)

Understood, I misunderstood your reply. Totally agree with understanding the reasons for the rules so you can adapt.

 

[JackD342]

When I train, I do my best to always include the "why" and not just the "what." Takes me a bit longer than some folks, but I am happy with results.

 

[Gareth J]

You answered my question. I think although it is probably covered in PADI material they do not stress enough what is really dangerous from what is not for emergencies.

Maybe this is better covered for rescue divers ?

I think most people understand that drowning can lead to undesirable death, so when you have to ‘save’ yourself, it is obvious that it is better to go through the stop than die

What was unclear to me is how to determine how much I can risk by helping my buddy and going through the safety stops. Now you have answered this very clearly: as long as you are in NDL (which I should be at my level of diving), it is okish to go through a stop to help a buddy if there is an emergency.

I am sure that if I re-read my material it must be written. But I don’t think it is written in a clear enough way or wasn’t stressed enough.


Thanks.

BlueTrin.

The safety stop is padding, its not a requirement of the calculated dive profile. It is basically a buffer. There are a lot of reasons why its desirable to have a safety stop, not the least of which is to make new divers slow down their ascent.
The biggest change in pressure is in the last 6m (18ft), which is why we want you to ascend slowly at this point.

So perhaps think of it as a pause during the ascent.

Most people think of a compulsory decompression stops, when they hear the phrase 'stop'. A decompression stop is part of the dive profile. It is a requirement of the safe dive profile, it is not optional.

Now modern (air/Nitrox) dive computers are quite conservative. (At least the recreational ones rather than the technical ones are[1]). The manufactures have added a lot of additional padding to the profile to ensure that it is highly unlikely that you will receive a bend, even if you are not quite upto US Navy SEAL levels of fitness.
So in an emergency, missing a few minutes of compulsory decompression stops is probably not going to result in any adverse effects. There does come a point where making a direct ascent to the surface, and missing compulsory decompression stops, does involve a risk to your own well being. If you are about to drown, then this is a lesser concern. If you are involved in rescuing your buddy - then only you can make the judgement of how much risk you are prepared to take. (For your wife you might ignore any risk, for someone you met this morning you might be more cautious).

Also, please remember decompression theory is just that theory. We don't really understand what is going on, we have some rules that we know normally results in a safe dive. It is not an exact science. You can be bent inside the table - i.e. following all the rules, and your dive computer religiously.

Gareth

[1] Technical dive computers are normally running the Buhlmann table. How aggressive they are is dependent on where you set the Gradient factors. So you can make them very aggressive - increasing the risk of a bend, or quite cautious, reducing the risk of a bend.

 

[Edward3c]

...I just came to a BSAC sports diver class and actually asked a fairly similar question, I am pretty sure from the looks of people that nobody knew the answer in the students but most of people do not ask questions becuse they are scared of looking ignorant.

Hi Bluefin,

The answer you should have got.

BSAC do not teach a timed safety stop. We teach stopping at 6m to conform everything is OK then take one minute to get to the surface. BSAC teach mandatory deco stops, but in an emergency stops would be missed to get the casualty to the surface and treatment. It is in Sports Diver theory ST2.

 

[KevinNM]

So this is interesting for me.

Are you saying that as long as we are in NDL we should bypass the safety stop if an emergency requires it ?

If an emergency requires it you bypass mandatory deco too. DCS is easier to fix than dead.