I've never had a problem selling myself on the need for something involving safety. Back in my Navy pilot days I remember all the training we received telling us how impossible we were to spot floating in the open ocean even if the rescue helo was within a mile of our location. We wore a survival vest attached to our ejection seat harness. Lets see If I can remember everything in that vest; signal mirror, day smoke and night red flare combo, a pen-sized launcher that fired starburst flares 150 feet high, 6 starburst flares, 16 ounces of water, a cigarette-sized handheld UHF radio/locator beacon with flashing night strobe, handgun, survival knife, dye marker, whistle, mylar survival blanket, about 8 feet of cord, some candy bar-like edibles, and our helmets were 100% covered with reflective tape. I'm sure there were a few more things, but that's all I can remember.
We were trained to use the radio sparingly to save the battery. Once communication was established and rescue less than 30 minutes away, we were to deploy the dye marker. Once the helo was within sight or ear shot, we were to use the signal mirror (if sunny), pop the smoke (day), or activate the red flare (night). And if they still lost us within the 3 mile rescue bubble, we were to start popping off starburst flares.
Divers get lost at sea a lot more than pilots do based upon what I've read during my two months of SB membership. Seems there are three big things missing from our survival gear options; radios, flares, and smoke. The options that are available are ad hoc at best, not designed for depth. Someone fix that.
My wife and I carry a 6' SMB with reflective SOLAS tape, 100' finger spool, signal mirror, Storm Whistle, Dive Alert (just recently purchased), 8 oz of water, 30 hour strobe light, battery powered glo-stick, chemical glo-stick, and backup light. At night we'd also have our main light.
I've been researching dye packs, radios, smoke and flares, but haven't found anything that I would have confidence would work for depth or not inadvertently deploy. Seems there would be a market for diver specific products. Tough to travel with the smoke and flares, but I bet dive boats would be happy to rent them for a small charge.
Extensive survival training should be taught as part of certification process.