another thing to consider is the boats noise policy.....
just because its a party boat, dont assume they allow loud music
a few years back we had a boat party on the thames, the rig must have been no bigger than 1k, yet we couldnt even turn it up halfway with out it triggering a cutout switch which would cut the power if the sound rose above a certain level..... pain in the arse, almost ruined the night
its like a little microphone, if you see one, throw a jumper over it