Bizer's web page,
www.bizer.com/w2sleep.htm, has a list of all (well, almost all) known hotels/motels/cottages that have docking for boats. It's just a list. One would need to contact the businesses directly to find their stay requirements. Additions/deletions/changes to this list would be appreciated.
When I started this survey, one hotel/motel had a docking price of $100 for the first night only (free otherwise). It kinda puts a crimp on a weekend visit by boat.
I say
almost all because ... When I went into one motel, they said that they did have docking for boats. The mature woman behind the counter requested that their motel not be on our list. Since Bizer started this list about twelve years ago, I have received two emails that said, "Hey you forgot xxxxxx"