Hand signals for remaining no-decompression Time

[scubadada]

I was never taught a standard hand signal. My family has always used the right thumb into the horizontal left palm (ie ceiling) followed by a hand signal for remaining time identical to air pressure remaining but in minutes, generally with one hand. We all dive the same decompression algorithm (Oceanic DSAT), so our NDL times are never very different. We probably would not ask unless our own NDL was reasonably low, few minutes. We use no signal for the safety stop as it is a given.

I generally go over this hand signal with assigned buddies when applicable. This is particularly important with significantly different decompression algorithms, ie. Suunto.

Good diving, Craig

 

[pixiefish]

As others have said, the little finger raised, or just tapping the computer, or going over and physically looking if they still haven't understood (although hopefully

we would have discussed this during dive plan).
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If you're diving nitrox purely for added conservatism rather than using increased NDL -

which I'm assuming seeing as you're diving with a buddy on air so you can't use your increased NDL time - you could just set your computer to air rather than nitrox, then your times would roughly match anyway.​

 

[FM1520]

I use the pinky or little finger for NDL and tap the back of my hand for pressure. I find the hand signals for numbers as illustrated above (index finger horizontal for six) is not universal. My dive buddy and I are both Navy and thats the standard hand signals so it come naturally. If I have a different buddy or insta-buddy then its part of the pre-dive check list.

 

[GrimSleeper]

Do any of you know of recognized hand signals for remaining no-decompression time, or if there isn’t one, do you have any suggestions for a clear hand signal requesting your buddy to signal remaining time. The reason I ask is that I’m afraid my better half do not really bother with decompression time, I can't assume what she has left as she dives with air and I dive with nitrox.

As Andy (Devon Diver) posted, the standard tec-diving symbol for 'How much decompression time do you have, old chap?' is an extended little finger, and it works perfectly well for 'I say... How much no-deco time remaining is your computer showing, old bean?'. As an aside, we've taught our dive guides to use it, we brief it, it's dramatically reduced the amount of having to swim over to people and look at their computers when they look blankly back at you as you tap yours. It's also reduced the amount of 'Oh, I didn't know what that number meant, thank you for holding onto me and ensuring I did my, what did you call it, mandatory decompression?' quite nicely, too, although that hasn't been a frequent problem. Never assume that number of dives = meaningful experience...

Since presumably you're diving with your better half as a buddy pair, why not, as someone else has suggested, simply set your computer to 21% Nitrox (aka air) so that you know yourself how much time you have as a pair? Unless you prefer packing her off to the surface and pottering about on your own for twenty minutes or so, I suppose, but I'm not sure that's quite the way we teach it...

 

[scubajo007]

Thank's for the replies. I think the easiest is to tap on the computer, however I will discuss the various signals with her and then we can agree which signals to use for request and response. Of course I could set my computer to 21% O2, but diving with nitrox then I prefer to set the computer to the correct O2%. I will see if she will do the full nitrox course and use EAN, then our NDL would be a lot closer even with a couple of %O2 difference.

 

[Lizard Leg]

Went over some of these signals with the wife and we are going to start using the raised pinky. Trying to get as many of our signals standardized as we can, but like someone mentioned earlier, it;s all academic as long as your buddy and you use the same signals for the same things.

 

[GROBIOG]

I think the raised pinky is for deco time remaining, not the NDL, how would you differentiate the 2?

 

[mathauck0814]

A raised pinky with a closed fist is the signal I'm familiar with for "I have deco" followed by the signal for a number indicating how much left at the current depth. If someone makes horizontal "slashing" hand movements raising a few inches every time and then gives the pinky and a number, we use that for total time to surface.

 

[Lizard Leg]

Okay, other than tapping your watch/computer, is there a standardized hand signal for NDL time?

 

[HowardE]

Tap the wrist watch means - How much time is left?

Generally, (like on most dive computers) they display the most pressing first. If air time remaining is the lowest number, then tell me that... if NDL is the lowest time remaining, then tell me that.

If that doesn't work.. I point at wrist, then my eyes like, "let me see"

Otherwise, if they're confused... I just grab their wrist, and look at their computer.