Radios, Sonar Communications, (Response to Charlie)

[Phil Nuytten <72020.572@compuserve.com>]

Gary - try Single Sideband . . .10 KHZ for longest range ( but lowest
intelligibilty) 30+ KHZ for medium range, high  resolution. AM systems are
simpler and cheaper but don't come close to SSB. We have tried SCUBA
communications, but they just dont have the oomph to punch through the
ocean thermoclines or provide long range. A good SSB system, between 10 -
20 watts , should give you clear comms at one mile range( in good
sea/ambient noise conditions). There are a number of systems on the market,
currently. 

Regards
Phil Nuytten