Renting a boat on Lake Mendota is always so much fun. The Skipper Buds staff is always really helpful and accommodating. Never driven a boat? They'll give you a little lesson before you begin.
We like to go to 3 foot bay to anchor our boat and relax in the shallow water.
All things considered, I don't think they're that expensive, especially when you compare it to all the costs associated with owning a boat. They have had a few Groupon deals lately which makes it more reasonable.
My only suggestion is to allow 6 hour rentals. The half day (4 hours) goes by so quickly but the full day (8 hours) is way too much.