I went and interviewed a couple divers asking them what the process is for diving. Most of them were moderately experienced (certified for 10 years, cave-diving certified, blah blah blah).
I learned some terminology, the equipment needed to dive, what kinds of lights they used, the process of diving (i.e., using your Buoyancy control device, how the regulator works and what to do when it falls out, the buddy system, universal hand signals, etc)
Here's 4 ideas. This is mostly focused on the communication aspect that I wanted to address.
I have 38 other ideas. I included most of the ones you guys recommended.So don't be afraid to say "these are bad ideas", because odds are I have a good one that I haven't posted up yet.
Idea #1: Smack this metal flashlight against your tank. It would be a very small attention-getting device. every time you hit it against your tank, the light flashes. Additionally, you get the very loud metal-against-metal noise. This would be glow-stick sized.
Idea #2: Signaling light. Side signals change color and intensity based on what signal you're giving. I.e: 2 red flashes means "I only have 500 pounds of air left" or something..
Idea #3: Keep track of your buddy's status. If he gets more than X amount of feet away from you, a warning light on the side of the flashlight is triggered. If his/her heart rate or breathing rate increases due to panic/accidents, the red side-light on your light flashes. I don't know what the technology would be behind this or how this would work, but it might be cool.
Idea #4: Little LED's attached to your flashlight hook on to points of interest. For example, when cave diving, attach one of the lights to the entry/exit point, as well as intersections. You could put the lights down periodically so that if your primary light goes out, at least you still have some ambient light to find your backup. Attaching them to the cave line would be a good idea as well. I'm not sure of the best way to re-retrieve them yet.
