Standardization of Hand Signals

[elgringoperdido]

It ain't rocket science. 14.5 psi = 1 bar. Therefore 145 psi = 10 bar, 1450 psi = 100 bar, 2900 psi = 200 bar, 3000 psi is a full cylinder, etc.

Regarding units, that should probably be agreed upon in the pre-dive briefing. It makes no difference whether you use psi, kPa, bar, torr, inHg, etc., because the conversions are easy, but just let me know which one you'll be using before we submerge.

To the OP I'd say that you have to just follow local customs. I tend to use TDI signs with the people I dive with in the North Atlantic off the NJ coast. We use one hand to indicate pressure. None of that two-handed or right hand on the left forearm signaling. On the other hand, almost invariably in the Caribbean everyone uses the PADI/NAUI signals, so that's what I generally use when I'm there.

For some of the other signs it can be really confusing. The first time I ever dived in France I saw someone giving what looked like a touchdown symbol. It turns out that this means "demi-bouteille" (I'm halfway to empty). Never saw that before but I saw it quite a bit since, although only with francophones. You just have to learn the local signs. This is also something that should be discussed on the shore or on the boat before descent.

Here's a placard that was posted on the wall outside a shop at Plage de Malendure in Basse Terre on the island of Guadeloupe. I found it useful while I was there and I remember thinking that I wish someone had posted that on the French mainland. In fact, all dive shops around the world should have something like this on the wall reflecting the local customs.

https://scubaboard.com/community/attachments/panneau-jpg.472860/

 

[Jai Bar]

In my humble opinion, it is insignificant whether a diver has 2317 or 2350 PSI, no need to communicate confusing numbers with intricate hand signals..

I use Bars and whenver need to communicate how much air left, I just round it to nearest quarter: 200, 150, 100 and 50 Bars. The same can be done with PSI.

Wheb buddy shows me his gauge, I don't care aboutnthe exact number, just the position of the needle in reference to dive's start and the reserve, so I don't care what units the gauge is.

As to rest of hand signlas, there are just a few ones that are really important and all divers know them and are familiar with, should be also established in pre dive buddy check. The rest are whatever.

It is more important to be precise and avoid misunderstandings with the simple important hand signs. If someone wants to tell stories underwater then wet notes or slate are a better option. One can also write canned messages on them, then point to buddy the relevant one when needed.

 

[rjack321]

I think the closest there is to an industry standard is from the WRSTC but seasoned divers may not feel very confident in the WRSTC's promulgation or emphasis on this given the underwater chaos we all periodically witness.

Standards Downloads - WRSTC

Dive Standards & Medical Statement from the WRSTC

wrstc.com

I think for more advanced hand and arm signals, it's best to work it out with your team. More advanced divers are likely to have refined signals anyways.

The only one I have an allergic reaction to is divers using the shaka in lieu of the pinkie finger for deco obligation. I've never dived with anybody whose skills I respected that used that technique; it's almost always an inexperienced diver short on training. The shaka is too easily confused with "Dude, that was cool!".

I reserve the right to change my mind if I dive with a seasoned, accomplished diver who uses the shaka for deco but I won't be bashful about saying it's a dorky substitute for the pinky.

There's this which is a lot better than WRSTC. And at least among technical divers fairly universal

Book - Cave Diving Communications - NSS CDS

nsscds.org

 

[steinbil]

In open water the thumbs up means we go the surface right now skipping the safety stop.

I wonder how common this is worldwide and if it relates to different training organizations.

Everyone I dive with locally use the "thumb up" to signalize "terminate the dive". It does not necessarily mean an emergency or an expedited ascent. In an open water NDL dive, that means to start the ascent from wherever you happen to be at that point, with normal ascent procedures, often shooting a bag. Sometimes that means making a direct ascent in open water, sometimes it means following the bottom contour towards the shallows. Depending on context, we might delay shooting a bag to more quickly get shallower, or skip a safety stop if needed – but that is usually determined along the way. As long as everyone seems calm and agrees, we follow normal ascent procedures. Sometimes it's given with an additional sign, like "question" on maybe a boring dive/site to indicate "should we just call it a day?" or "swim this direction" to indicate let's end the dive by following the bottom contour to the shallows.

If the thumb is given before the planned end of the dive, ie. not on gas or time, and without further communication like "I'm cold", I would pay close attention to my buddy to see if they are comfortable or stressed, and start an ascent without delay. If on a GUE dive I would do the min deco ascent, if with another diver, we would stabilize at 5m for a safety stop, and then I would ask them if they wanted to complete the stop or go to the surface.

This is similar to the procedures of a Tech dive. If the thumb is given, everybody replies with the thumb and immediately starts to ascend to the first stop depth, unless there is a required swim to an upline or a "thumb-with-index" finger to indicate making your way to the exit point. No questions asked, and we follow normal ascent procedures with gas switches and planned deco. If dive is terminated ahead of planned bottom time, we agree on adjustments of the deco schedule on the fly. In an emergency you would obviously need to make further decisions along the way.

To go to a shallower depth the palm up open hand is given while raising the hand. Additionally, a new depth can be signaled.

In my circles, the signal is given with palm down and the hand moves in upwards arc, starting and ending in a flat horizontal position – almost like drawing a sideways U with a flat hand. This signal is used mostly in 2 ways:
1. to change to a shallower depth on a multilevel dive
2. to go to next stop depth (min deco ascent or deco stops)

The signal with palm up and raising the hand, only means 1 thing in my world: "You are too low. Get up to our level/stop." This would be given if someone drops below the target depth on a deco stop, or if someone is crossing the MOD or planned max depth. Or possibly just to tell your buddy to get a little higher for another reason - maybe if they are inadvertently touching the bottom/stirring up silt, or something like that. I've never seen that signal to mean ascend as a pair/team.

 

[mar2112]

My buddy and I have agreed to signals. When we dive with a DM they, in my experience, always brief how they want air pressure communicated.