There are several types of boats to choose from depending on how much you want to spend. We got the pontoon boat with sound and anniversary decorations which I think came up to $300. We split the boat with 2 other couples that I met on disboards that were celebrating anniversaries too. You could always rent the ChrisCraft which was much nicer but much more expensive, too, but that would certainly be very romantic. The anniversary package comes with balloons and an anniversary banner. You can also have a cake or other food delivered to the boat, and can bring some bubbly if you want.

We also did the Backstage Magic Tour that morning. It's 7 hours of lots of walking but fun and interesting. DH has back problems, though, and it was a bit too much for him.