On Mon, 08 Oct 2007 11:35:28 -0400, Gene Kearns
wrote:

Unfortunately, it is more or less a work-around. AFAIK, there are no
PLBs available (at least in the US) that are waterproof for any length
of time over about 1 meter deep. So......... what makes this thing
work is the optional "dive canister," which is good to about 540 feet,
IIRC.

Thus, only useful on the surface.....

There's a problem with the whole concept. The diver is most likely
already dead when an alarm or beacon is noticed. It doesn't take long
to get into trouble underwater.