Blue-green light has the
greatest depth of penetration in seawater. Blue-green lasers have been
used to map water depths in at least 200+ feet of water. They have also
been experimented with for very covert communications with subs but due to the
very narrow beam width of the laser, you would have to be almost over it for
it to be seen. Currently green lasers are the most expensive of the
various colors available and then when you consider the power required for
identification (and even a lot more for 2-way communications) if it were to be
feasible, you could buy many top quality EPIRBs, UQCs, pingers, and
trackers.
R/Jay
From:
owner-personal_submersibles@psubs.org
[mailto:owner-personal_submersibles@psubs.org] On Behalf Of
vbra676539@aol.com
Sent: Thursday, October 29, 2009 7:23
PM
To: personal_submersibles@psubs.org
Subject: Re:
[PSUBS-MAILIST] Lasers u/w [was:R300 Dive 3
This
isn't new tech. HBOI was using a pair of lasers to define the precise focal
length for stills and video decades ago. That kind of thing is available
through the camera manufacturers, I suspect. Don't know about long range,
other than that Chris Chulimanus told me that green light works
best.