OP
Lynne, while what you say is MOSTLY true regarding systematic diving the very reason I decided that a review of signals was absolutely necessary is because of the number of "board meetings" that have taken place when it was time to turn the dive. In one class, I had three divers trained by the same DIR agency and the same instructors pull out three different turn signals. "Direction to exit." "Turn around." "Terminate the dive." While the meaning under the circumstance was clear, it was still sloppy.
I usually have to train out the thumb + index finger habit that indicates the direction to exit and replace that with thumbs only for "Call the dive." I have had DIR students who told me that the thumb up meant to ascend directly such as in an emergency, while others use two thumbs gesturing to move rapidly up in an emergency, etc. I'm not sure they are getting that from instructors and may be confusing signals from videos or from poorly informed DIR practitioners. I know in my GUE classes I was taught that a single thumb (whether in cave or open water) meant, "Call the dive. Let's go home."
I used to allow students to add thirds, time or deco to a thumb to provide the reason the dive is being called, but now I seek absolute simplicity and discipline in hand signals and light signals.
Anyway, with these ideas in mind, I find that it is important to review all signals that will mostly likely be critical to the dive performance just to make sure everyone is on the same page even when like-minded divers get together. Even the best trained and systematic teams begin to develop their own style of communication that might not be understood by another philosophy adherent team. I call this "creep." Things begin to be modified by individuals and teams and slowly creep away from the original procedure. Or, when things become updated by an agency, they are ignored by veterans who have already become entrenched in the way things had been done.
