For sporting purposes, I have a 12-gauge bang stick I use down below in case of the rare predatory shark, or those equally rare times the thing I want to eat is as big as me. I prefer to catch that fish from the surface, though. But when opportunity knocks…
I have a Remington 870 marine-grade 12-gauge “shorty” on board but am loathe to use it because, although I’m sure to stop the intruder, I would have to spend the next week working on repairs. I also have a carrying permit and a Taurus 9mm semi-auto somewhere around here which I haven’t seen much of since I left the states.