I've tried Ducky, Vinager/water combination & Babes. I like Babes when it's on the trailer. If I'm on a lake for a long time (> day) like lake powell, I'll have my kids wipe it down with Ducky while it's in the water - takes 5 mins. The last boat was black/red. The black was fun to keep clean.
I wipe the boat after every use and wax a few times a year.