I have started using a throwbag in the front of my playboat because my students keep losing my foam out when they use my boat. In the past, I have set the boat on a piece of foam, cut one edge. Bumped the boat over about a half inch. Cut the other edge. Adapt from there.
That or go to the wave, stand next to a similar boat, and yell "whoa look at that!!!!" instant bulk head.
Not wanting Karmic debt, a small speed loader is about the right size.
friend of the fork, knife, and spoon