VHF waves work "line of sight". They may be slightly curved around the horizon but
they won't be much. So, whatever the power of the transmiter is, they won't reach
more than 25 miles before getting lost in space. Frequencies used by SSBs, like
HAM radios, will bounce on various layers of the the atmosphere and get back down
beyond the horizon. Various frequencies will bounce on different layers of the
atmosphere, coming back down at different distances and knowing the properties of
the various wavelenghts is important for reaching the proper distance you want to.
The point were they bounce back down will be "deaf" on the ground so the use of a
SSB is not as easy as tuning channel 16 on a VHF. Training on using these radios
is necessary for getting your money's worth.

Jean Dufour
Montreal, Qc

Bobsprit wrote:

I'm not clear on marine SSB radios. Can someone explain how they differ from
standard VHF? A friend is now offering me a pretty expensive Icom SSB. I doubt
I have a need for it, but it's basically free. I may just tell him to sell it
on ebay. I was thinking of adding a AM/SSB (CB) radio to the boat which would
be better than the GMRS.
So can someone explain what the marine SSB is? Is it VHF with upper and lowers?

Thanks in advance...

RB