Grampaw,
As wet as cajunland is, you should have no trouble finding a place to fly floaties. Even a low spot in a field after a good rainstorm will work. You only need a couple of inches of water.

For a boat, a bateau or jon-boat works great. I had one of those Coleman plastic 12' jon-boats with a trolling motor and it was near ideal. A canoe would work if you can reach over the side and lift the plane in without tipping the boat. If you are in bigger water, a bass boat or a pontoon boat would be cool. You just have to go slow with the bass boat or the plane will blow around when you're carrying it and not flying it. I had an 18' runabout that was not very good for flying from because the freeboard was too high and it was uncomfortable reaching the water to lift the plane.

You could host the Lake Ponchartrain float-fly and Crawfish Festival.