If you must have an event on a boat, or near water, here is an option for some.
It is an old ferry boat from the former Gig Harbor Tacoma ferry run.
It is a decent space, although it is kind of weird that it is separated by the staircases that lead to the passenger deck. The rooms are where the cars used to park. the boat doesn't move. It is a bit difficult for sound purposes because the people usually eat on one side of the boat and then dance on the other, making getting adequate sound to the other side difficult, and the venue doesn't leave really any room for additional speakers to be placed.
One of the event planners on the boat is not personable AT ALL. The one who usually oversees events is good at her job, as well as friendly.
Why anyone would want a party on a boat that doesn't move I don't know... must be a shortage of reception spaces.