yep, done a lot of em'.
one thing I recommend to all boat owners........... Plan for a bigger system than you might do in a car. If you really want to hear it over the sounds of the motor, the water, and the wind. It needs to be a pretty big system. Know what I mean?
Second, don't buy "marine speakers" they're more expensive than they're worth. Any good poly-coned speaker should do just fine. It's not like they're ever gonna get that wet.
Third, don't give the excuse, "It's just my boat, I don't wanna put anything fancy in there." That doesn't make any sense. You can afford to buy a 25,000 + dollar toy that you only use 4-5 months out of the year? But you won't spend an extra $500 -$1000 to put a nice stereo in it? Lame
Fourth, boats are perfect candidates for security systems (though probably not something you should do yourself". There is probably a lot of expensive equipment in there and you probably just park it on the side of the house right?
I love doing boat installs! If you need any more specific help PM me