: colored tape on the snorkle is a great idea. As for the glow sticks, just regular glow sticks? They'll handle the pressure?
Good question. Yes I'm referring to the regular snap sticks for camping and other such fun.
They are cylindrical and nearly fluid filled. They are compliant enough to allow for the activation snapping so that would probably allow for the bubble compression deflection.
They are SOP for night dives, unless you have a tank light. They are prohibited in some resort regions for the ovbious litter / chemical risk. I've never heard of them failing at depth.
As others mentioned buddy recognition is an acquired skill. With a little more experience you may be diving in less than a mob and the confusion will lessen.
Pete