On Mon, 15 Aug 2005 17:59:27 -0400, Skip Gundlach said:
... My challenge is to get the signal not only out of the
boat, but down to my laptop, wirelessly. I can do one or the other
brilliantly. So far I haven't done both in one box.

So don't. Keep a cheap wireless AP in the cabin in your boat, run UTP ethernet
cable to the masthead device, along with the 12V, presuming you were already
running that. The requirement then isn't whether the high-gain kit can send a
usable omni signal too, but whether it has an ethernet interface.

So, as the computer expert, leaving the challenge of antennas to me, what
(12 V input, thank you very much) device does what I need? I'll figure out
how to antenna it and elements-protect it.

You might have a look at some of the many websites about building wireless
community networks. There's even a book of that title on O'Reilly press these
days. These places will be where pushing the limits or 802.11 gear is routinely
discussed.

There are links to some such networks at:
http://en.wikipedia.org/wiki/Wireless_community_network

For what you are proposing, as I understand it, two antennas/interfaces
seems to be the go. If you consider they are doing different jobs, it makes
sense. It's only a pity the masthead device is USB: if it were ethernet, all
you'd need would be an inexpensive wireless AP that is also an ethernet switch.
As a bonus, any non-wireless computer you subsequently installed onboard would
have a wired switch port to connect directly to.

Also note that you're not restricted to devices that come with supply units
that can run off 12V: most devices like this have extremely modest demands
and dc-to-dc supplies of various capabilities are readily available.

--Damian