I was taught (PADI Instructor) 1,2,3,4,5 fingers up or 6,7,8,9 fingers down and circle for zero. I was with another PADI instructor for a leisure dive yesterday who "misinterpreted" my five fingers up to mean 1,000 as opposed to 500 because he "thought he saw me flash it twice." . . . My question being, what is the PADI (and other organizations) standards in air signals? If there are several, then why is this not standardized?
Great questions! And, as turisops points out, there really isn't a 'standard', at least not one of which that I am aware. I was taught, and subsequently teach my students, the same approach that you learned. It is summarized in the video that kevrumbo shared. A difference - I don't roll my hand to the horizontal position for the 'zero', but that is a minor variation. I find that - once a student learns this approach - communication of remaining air supply is easy. But, it is a learned skill.
Some thoughts, reading the responses.
1. Sometimes, if a student is having trouble with the hand signals, or gives me a response that doesn't make sense, I will swim to them and look directly at their SPG. I tell them that I want them to try hand signals first, they need to learn the skill of using hand signals. I don't want them to simply hold up their SPG because I may or may not be able to read it if I am 3 ft away.
2. I dive and teach in a psi world. So, it was informative to see that the video clip involves bar numbers. The system works well for both, as far as I can tell.
3. In my psi world, I tell students that I only want the first 2 digits - if they have 2400, I want to see a '2' then a '4' - communicated as two fingers up, then 4 fingers up. If they have 1750, I want to see a '1', then a '7' - communicated as 1 finger up, then two fingers extended with the hand in the horizontal position. I don't need 4 digits. Thinking about that approach after seeing the video clip, I wonder if in a bar world I would ask for 3 numbers. CFS's comments seem to suggest that 2 digits still works in that case.
Why aren't these signals standardized? I honestly thought they were, after I took my OW class, only to find out later that they are apparently not.
But, from my perspective, the one 'standard' that should be followed is having SOME system, that is communicated and agreed during the pre-dive briefing, i.e. before ever getting in the water. When I work with AOW studnets who may have learned a different system in their OW training, the important thing for me is making sure I can understand whatever they are using.. I will still ask them to try 'my' way. But, I will accept their approach, as long as I know what it is before we submerge.