LOL@Rhone Man
Yes, that is exactly what I am saying, why not leverage helium to lift your marker much higher, air rescue can spot it much more easily, plus you don't have to rely on unreliable electronics. DCBC, the expense of a GPS EPIRB device is not really appealing to most. This could be a much more practical solution. That design that you identified looks like a concept, is it in production? besides it doesn't look it is packaged to be taken diving.
If I could send a 6+ft sausage 20-30ft in the air I'm confident that air rescue and even boats in the distance will definitely be able to spot me. I'm just puzzled that this type of product is not even available and widely used in the mainstream, there must be some technical difficulty with implementing such a device... I would like to know what it is. My guess is buoyancy related, how heavy would a canister need to be to cancel out the helium? not too heavy I'm thinking.