Re: Does anyone know anything about boats and radio?
Are you talking about taking a cruise ship, or is this a private boat, or boats?
If you're just dealing with broadcasting for the ship, you'll only need a couple watts of power, and once you're beyond territorial waters, it won't matter.
As for legality of it, you'll need to know whos waters you'll be in, and what their laws are about it. Can't really answer that one.
I've considered setting up a pirate station.
Check this out for a ton of info, if you haven't already.
http://www.freeradio.org/
The key to getting away with pirate radio, is not pissing anyone off. meaning: Keep it 'G' rated for whoever stumbles across it, and don't step on anyone elses toes on air (make sure you're using a dead spot on the dial).
Link has more.