Spending time on the Vltava is a great way to round out your experience of Cesky Krumlov, especially on Mondays when local attractions and some shops are closed.  Several companies in town offer rafting and canoeing for groups as well as bike rentals.  You can choose from a short float trip around town to a 3-hour float trip to a small monestary and town to 5-7 hour trips with more whitewater.  Malacek and Vltava are two companies that offer these services.  A beautiful way to experience a bit of the Czech countryside and have a fun, relaxing day!