I've called in a couple rescues (including for a pair of jetskiis on the Bay on a 4.7 day) on the Apelco 102, now the Raytheon 102. See:
http://www.raymarine.com/raymarine/ProductDetail.asp?
site=1§ion=2... 6&product_id=590
It's got 5 watt transmit power. Several other folks have the Icom M1. It's got favorable reviews and it's very compact. The M2 looks like a nice model as well. See:
http://www.icomamerica.com/marine/index2.html
I think you can get both from West Marine.
http://www.westmarine.com/webapp/commerce/command/
CategoryDisplay?cgm... 1&cgrfnbr=138&outlet= and it'll automatically get the benefit of West Marine's warranty. The M2's on sale for $179 right now.
Carry the radio in a drainable fanny pack, keep it charged and check the contacts for corrosion fairly regularly. I also keep mine in a waterproof bag which I tie on my harness in case the fanny pack get's detached somehow. Also, learn proper marine radio etiquette so people will talk to you:
http://www.boatingsafety.com/vhf1.htm http://www.navcen.uscg.gov/marcomms/boater.htm
Good luck. It's a good investment.
-Ed