"Here in Maine we used to have the "duck guns." These were small cannons placed in the bow of our punts (no, that's not a pun but a flat-bottom rectangular row boat). You could mow down an entire flock with one of those or a small village if one was within range. I think they're now illegal to use for hunting but you can still collect them."

James Michener mentioned them in his historical novel, "Chesapeake".