From another NG:

Bring your boat to Louisville this June and take a two day trip on the
Ohio River with seasoned river boaters. This is a great opportunity
for those who have not experienced the beauty of the river and would
like to do so in the company of those who know it well. No costs, no
sign-up, just join us. For details go to:
http://www.riverlorian.com/riverconvoy.htm