Hand signal to end/terminate dive?

[Belzelbub]

Yep. Thumbs Up means dive is over. We can talk about why at the surface, but we are going up.

I've only once used Thumbs Up for a slightly different reason. In this case, it was meant as a question and planned and discussed ahead of time. I was taking my younger daughter on her first ocean dive. She had previously had nervousness on first dives, then got over them, and enjoyed herself. I figured this would be the case. So, at the surface, I told her we would descend to the bottom, then I'll give her the thumbs up sign and we can go up if she wants. When we got to the bottom, I gave the thumbs up as discussed, and as expected, she shook her head "No."

So, kind of the same meaning, just was meant that time as a question, but given the different intention, we had to talk through it first.

 

[inquis]

So, kind of the same meaning, just was meant that time as a question

I would have given the Question symbol before the thumb in this case. (If you haven't come across Question before, it's really useful.)

 

[inquis]

Let's start heading back to the entry point.

I use Turn (horizontal circle with vertical index finger) for this. (I also favor single-hand signals, FWIW.)

 

[Belzelbub]

I would have given the Question symbol before the thumb in this case. (If you haven't come across Question before, it's really useful.)

I haven't. Got an example of the Question symbol?

 

[tbone1004]

 

[Gareth J]

I use Turn (horizontal circle with vertical index finger) for this. (I also favor single-hand signals, FWIW.)

We use Turn, but in tends to be more seriously, i.e. on deeper dives, where gas/time are constrained, a more technical runtime dive.
Home, is quite laid back, when you are on a shallow hunt the critter dive, you have loads of gas, loads of time. A bit of a hurry up is if you add cold signal to the home signal.

 

[Lorenzoid]

I would have given the Question symbol before the thumb in this case. (If you haven't come across Question before, it's really useful.)

I would only precede the Thumb sign with the Question sign if we had discussed it ahead of time (as in @Belzelbub's story). But for minor exceptions like that, the sign to "end dive" should be unambiguous, because it means there is no room for discussion, no dilly-dallying--the diver needs the dive to end. The sign to end the dive may be the most important sign we have--possibly more important than the OK sign.

 

[Alaskan Scuba Dude]

I would extend index finger and thumb to end dive followed by three fingers below the palm of your hand.

 

[EFX]

Regardless of the signals used, it is important to go over all the pertinent signals with your buddy(s) before starting the dive. I use the one-handed cave diving signals.

Inside the cave or cavern the thumbs up signal means "exit the overhead immediately and complete any deco or safety stops in open water before surfacing". In open water, thumbs up means "surface immediately without completing any stops". This may not be an emergency but the diver giving the signal is under serious distress and needs to surface. It could be an equipment problem that cannot be fixed underwater or a physical/medical condition that hasn't resolved itself. There may be no problem at all. The diver just wants to end the dive and get out of the water ASAP. Often, it is given at the completion of the safety stop or last deco stop.

The signal for deco or safety stops is the raised pinky finger. This might be followed by the number of minutes for a safety stop, or the depth of the deco stop. To signal going up to a shallower depth an open palm facing the surface is used and raised toward the surface. Usually, this signal is followed by the new depth. A thumbs down is used to signal going to a deeper depth and is usually followed by the new depth.

 

[tbone1004]

Regardless of the signals used, it is important to go over all the pertinent signals with your buddy(s) before starting the dive. I use the one-handed cave diving signals.

Inside the cave or cavern the thumbs up signal means "exit the overhead immediately and complete any deco or safety stops in open water before surfacing". In open water, thumbs up means "surface immediately without completing any stops". This may not be an emergency but the diver giving the signal is under serious distress and needs to surface. It could be an equipment problem that cannot be fixed underwater or a physical/medical condition that hasn't resolved itself. There may be no problem at all. The diver just wants to end the dive and get out of the water ASAP. Often, it is given at the completion of the safety stop or last deco stop.

The signal for deco or safety stops is the raised pinky finger. This might be followed by the number of minutes for a safety stop, or the depth of the deco stop. To signal going up to a shallower depth an open palm facing the surface is used and raised toward the surface. Usually, this signal is followed by the new depth. A thumbs down is used to signal going to a deeper depth and is usually followed by the new depth.

Normally you are unable to complete any stops outside of the over head in a cave/cavern, especially in Florida.
I've also never seen a thumb in OW to mean skip any stops.
In the circles that I dive they have always meant that the dive is over and we are going to the surface but not skipping any decompression or precautionary/safety stops.

Flat palm up is usually a signal for pressure with flat palm down being the signal for depth. Palm down and ratcheting it either up or down signals a change in depth. Exception to that is if you have a flat palm up and are moving your whole hand *similar to the end of the signal in the video below* to indicate ascend a little bit, but that is usually only used if a diver is riding too close to the bottom and needs to lift off a little bit vs. a real depth change. I know that seems conflicting since coming off the bottom a bit is a depth change, but if we are on a reef and are riding the sand and you give the palm up gesture it usually means to come off of the sand a foot or two for whatever reason vs a palm down depth change gesture to indicate moving from riding along the sand to moving along the top of the reef and making a meaningful change in your depth.

You can see in this point in the video the diver signaling a change in depth to 6 meters.
Flat palm down ratcheting up to indicate we are changing depth to a shallower depth. At deco this is implied to be in 3m/10ft increments.
"6" to confirm the next depth
"come here" with the palm up and a pulling all fingers up a bit to indicate let's go.