Mike, I'm not dogging your skills or your intentions, and sorry if it came across that way.
But you've obviously had some experience in low vis conditions, per your post:
mikerault:
..."even when striving to maintain contact with a buddy in low visibility conditions it can be quite easy to lose them. I know because it has happened to me several times even when both buddies were doing everything they could (short of holding hands) to stay together...In water with less than 5 foot of visibility it can be easy to get 10 foot away and then you might as well be 100 yards away"
This is why in cave courses students are taught to follow the line out in touch contact should the visibility be silted out, and to "spell" hand signals into each other's palms or use "shoves & tugs" via touch contact to communicate.
Using your own scenario from your quote, suppose you and your buddy are separated from one another in a silted out section of Lake Lanier, and he uses a device like this to signal you he's in trouble.
Which direction do you start swimming to get to him?
If you even had full face masks with radio communications, the conversation would go something like this:
HIM: "Help, I'm stuck under something and low on gas"
YOU: "Where are you?"
HIM: "Last I knew about 15'-20' from you"
YOU: "In which direction?"
HIM: "I was behind you over by the rock, not sure of the compass heading, where are you now?"
YOU: "Dunno, can't see. Not sure which direction is now "behind me" from a few minutes ago"...
[and you get the idea]
My skills are a long way from perfect and I need all the practice that I can get. But for the diving I do, one of the fundamental things I've learned is that if I have a buddy I stay within communications/visual range of that buddy constantly, and as the vis gets poorer that distance diminishes to the point of touch contact (and by then we've thumbed the dive).
I'm not dogging your intent, heck I'm all about safety.
It's just that in my experience when emergencies happen they tend to happen suddenly, things go downhill fast, and if your buddy can't find you due to proximity issues and/or low visibility, then an electronic signal that you are in distress is not likely to speed up your buddy's locating you in time to make a rescue.
mikerault:
"I don't mean for this to replace skills only to make diving safer for those who can't practice every weekend."
I understand what you mean, I think, it's just that we come at it from two different directions. IMHO, the divers should slow things down and work with each other so that they stay together regardless of how slow that makes them, rather than losing one another.
But that's simply my opinion. Heck, go build the thing!
You'll probably be sitting out on the deck of your yacht retired while I'm still slaving away and eating fried catfood!
