In real subs, they use LF(Low Frequency) or ULF(Ultra Low Frequency) to
carry signals through the water.  It is also very high power, and poor
bandwidth.  The
bandwidth problem is somewhat minimized by the use of codes, that get
expanded
on the receiving end... however..

If you want to use a camera, about your only option is to tie a balloon or
something
to an antenna to float it to the surface.

Craig

----------
> From: SHAWN ELLIS <spe@MERC.RX.UGA.EDU>
> To: PICLIST@MITVMA.MIT.EDU
> Subject: Re: OT: Radio Transmission in Water
> Date: Wednesday, March 04, 1998 10:34 AM
>
>
> > Hi Folks,
> > I'm sure one of you out there will know the answer to this one.
> >
> > Anyone any idea how well a 1.3GHz radio transmission will penetrate
fresh
> > water. I build model subs and I know that standard 40MHz Radio control
gear
> > works well down to ten feet or so. I'm thinking of mounting a black and
> > white TV camera on a sub. I've seen a transmission system that uses the
> > 1.3GHz telemetry bands to carry a video feed, but I'm not sure how well
it
> > will work.
> >
> > So any help would be much appreciated - Oh and it is not that off topic
the
> > Sub has two PICs in it, one for depth/attitude control the other for
speed
> > control!
> >
> > Andy
> >
> hmmm, my guess is you'll be lucky to get 1 inch!  Probably have to
> use something really powerful anyway...  Are you sure you can't have a
wire?