One good aspect of this problem is that magnetic fields are
not effected by water very much.  It is my understanding that radio
signals have two component fields.  There is a near field which is
magnetic in nature and a far field which is electrical.  Signals which
bounce off the ionosphere and travel great distances do so via the
electrical field while antennas that use the magnetic field such as
the rod antennas being discussed work best on magnetic pickup.  I
would think that the water would not effect the magnetic field much so
the close range communications would still work.

        Anybody who knows the theory which I am talking about is free
to step in here and say that I am full of hot air, but this is the way
I understand it.

Martin McCormick WB5AGZ  Stillwater, OK
OSU Center for Computing and Information Services Data Communications Group
ftpMaster writes:
>The US Navy uses extremely long waves <30kHz for communications with
>(underwater) submarines all over the world. If You use a frequency about
>455kHz (IF for AM radios) it will probably work, and also use common
>components like ferrite antennas, resonators, ceramic and LC filters.