I know you know this, but it bears repeating for folks that don't. I don't care if the Shotgun has "Marine" written on the side of it - they do NOT float, I checked twice to make sure.
Pleasure Crafts...
14ft flatbottom: I used slugs, various buckshot, 1 1/4 oz loads of # 5 hard shot,and some Skeet loads with #8 shot.
This was dealing with Beaver Dams, snakes, alligator gar, snakes, explosives, snakes, Beavers, snakes and beavers...did I mention the snakes?
Ranger Bass Boat: Striper fishing, Slugs, #1 buckshot ( gun patterned these best) more slugs, and the 1 1/4 oz of #5 hard shot.
Chris Craft : Slugs, flares, slugs, 00 buckshot, slugs and a couple cases cases of AA Target loads, Target thrower, and White Flyer Targets. *ahem* undisclosed part of waterway, around some islands, where supposedly resides deer, bear, panthers and other critters...well I guess shooting targets off the stern worked - we never were attacked, raided, boarded or whatever it is happens to folks in big fancy boats.
Pelican water resistant cases are great for ammo storage in 'wet enviroments'.