The Skansonia is a historic ferry boat docked on Northlake way. It is used for different events including my wedding. It has a gorgeous view of downtown and the boat itself has a lot of old fashion charm. It isn't very big. We had about 150 people and that seemed about right, although I think they say you can have up to 200 or 250. It might be too crowded at 250 people. Our guests said the food was really good. I agree, but it is nice to hear that from guests (I don't know if I've ever complimented wedding food). They also have bartenders for hire and you supply the beverages. This was a fun way to personalize the reception by offering our favorite beverages, not to mention it saved us a ton of money.
The people that run the venue run it a bit like a wedding factory. There isn't a lot of customization options. Mostly they told us how it was going to work. For the price and the view, we went with it. I did get a bit irritated at the end of our reception, because they started to clean up before everyone had left (I don't think it was after our rental time either). They said they had to get ready for another wedding that night. I thought it was a bit tacky. You might want to clarify that in your contract.
I also know of a UW sorority that had a dance at this venue and everyone seemed to really like it.