Ideas? Sure! Here's a big one for you to chew on.
The first time you mention in a publication that you are taking people up the river to 'float-down' you will be named as defendant or co-defendant in a law suit that will put you either in the slammer or in poverty row....the first time some poor slob drowns in the river, thanks to you're endorsement of the activity. You are in the transportation business. Whatever somebody decides to do after they get off your train, is their business....not yours. You are in the transportation business. Limit your liability to that, and that alone. Get the stars out of your eyes and talk to a lawyer or insurance attorney to make sure your skirts are clean. Nuff said.