Deep stop hand signal?

[tursiops]

I've learned that in no-stop open water diving, the thumb means "this dive is over".

Is this not true for non no-stop diving too? Or, to avoid the double (triple?) negative, this is true for all diving.

 

[Bigbella]

 

[EFX]

I've learned that in no-stop open water diving, the thumb means "this dive is over". There may be many reasons for terminating a dive, and many of them don't preclude a safety stop. So, if I or my buddy thumbs the dive, we'll ascend to safety stop depth where there will be a short discussion (diver 1: flat palm downwards, three upright fingers below. Alternativey, "level off" followed by "3". If the other diver gives the thumb again, it's surface time. If the other buddy confirms the suggestion for a safety stop, then safety stop it is).

What I bolded above in your quote is the usual meaning accepted by all buddies (not my regular buddy) I've dove with. If we are below the safety stop depth the flat palm on top of three upright fingers means "I want to ascend and do a 3 minute safety stop". The thumbs up sign if it's below safety stop depth means "let's go up to a shallower depth". After the SS it means let's surface now. I've reinterpreted the two signs based on the NACD book and my regular buddies preferences. I haven't been very successful in getting my inst-buddies to accept these variations so I just go with the "standard" meanings for these signs.

 

[Storker]

Is this not true for non no-stop diving too? Or, to avoid the double (triple?) negative, this is true for all diving.

That's my impression, too. But I haven't had any "real" technical training, and the post I replied to was about a type of technical diving that I've only read and been told about.

Thus the caveat

 

[Storker]

What I bolded above in your quote is the usual meaning accepted by all buddies (not my regular buddy) I've dove with. If we are below the safety stop depth the flat palm on top of three upright fingers means "I want to ascend and do a 3 minute safety stop". The thumbs up sign if it's below safety stop depth means "let's go up to a shallower depth". After the SS it means let's surface now. I've reinterpreted the two signs based on the NACD book and my regular buddies preferences. I haven't been very successful in getting my inst-buddies to accept these variations so I just go with the "standard" meanings for these signs.

If we - hypothetically - were to dive together, we'd need a pretty thorough pre-dive chat, because otherwise we'd have some serious communication issues.

I use the signs like this:
Ascend: palm down, move hand upwards. May be extended by indicating the target depth.
Abort dive: thumb
The safety stop sign is used at safety stop depth, not on the bottom.
I might indicate that I'm done and want to go to the safety stop by showing the thumb below a flat palm, but since that isn't a standard sign I'd mention it to my buddy during the pre-dive chat.

And to get back on topic, if I wanted a stop at half depth, I'd tell my buddy "ascend", "stop depth". At stop depth I'd say "level off", "stop time". But if I had a proper buddy, I probably wouldn't have to say anything. We'd be following each other closely enough that if one of us stopped, the other one would stop, too

 

[HKGuns]

My Oceanic Pro-Plus 3 also had an option to turn on deep stops. I left it turned off for all of the good reasons mentioned further up in this conversation.

 

[racerx_]

So if you went to do a half depth stop for a 25m dive, would you stay 3mins at 12m in addition to a stop at 6m ?

Are you feeling better because you just did a longer stop or because you did a deeper stop ?

I.e. would you feel even better if you doubled the time you stopped at 6m and didn’t stop at 12m ?

Sorry somehow missed this.
1) yes a stop at 12 in addition to 6 meters is basically what would happen.
2) I can’t answer this definitively. Good question though. I’m not sure if I ever played around with longer stops as opposed to just adding a deeper stop. If I did, it was early on in my diving so I probably wasn’t familiar enough to tell the difference anyway.

I’ll try some longer stops next time I’m underwater once we’re out of Coronaville. Although since diving in S.E.A. Is all guided it tends to confuse the guide if you’re up there doing a long stop while they’re finding Nemo below ha.

question: in the recent study Mark did that’s referenced here, what was the depth of their first stop for the shallower stops?

 

[KenGordon]

How do you make a deep stop hand signal?
For example, telling your dive buddy that you're going to a do a deep stop at certain depth for a certain duration.

If you are still here after all the cave diving chest bashing...

As you are aware computers will insert a minute or two in the middle of an ascent. The exact rules are slightly variable and don’t really matter. Whether it is worthwhile or not also doesn’t matter. What matters is that you and your buddy are on the same page when it happens to avoid confusion.

I suggest reminding your buddy beforehand or at the buddy check that your computer might give you a deep stop. Agree with them what you will do. Arcane technical hand signals are not required, whatever your normal signal for a safety stop or just a stop signal would probably suffice.

 

[KenGordon]

question: in the recent study Mark did that’s referenced here, what was the depth of their first stop for the shallower stops?

They compared GF settings. Since these were real divers in real water, not a wet pot, they will have followed their computers. The site is 75m to 80m max but you can more or less choose any depth between 50 and 70 and have a place to go. I was not there so can’t tell you the planned depths.

 

[KenGordon]

@DiveTucson Thank you. Would you please explain why you don't think it's appropriate? Or is there any theory to support not doing so?

Both the links a provided in reply to this post are about deep stops in dives with considerable deco stops, not ones with only safety stops. It is already difficult to draw conclusions between the NEDU study dives and ‘technical’ (ie recreational deco) dives.

In the end the conclusion is that some profiles, with deeper initial stops than others, add extra nitrogen to slow tissues and that does more harm than going shallow sooner and exposing fast tissues to higher pressure gradients for a short time. It might be that the same logic applies to a couple of minutes at 17m, or not. A deep stop profile on a 60m deco dive might move the first stop from 18 or 21m to 30 or 33m. Personally I think a couple of minutes at 30 odd is much more significant than a couple of minutes at 15 to 20, so I don’t worry about the deep stops on NDL dives.