I've never considered a flooding, as so far (touch wood) the area where I live is not likely that it'll ever get flooded.
Anyway I keep most of my guns in a biggish safe in my "bunker", that's what my wife calls our cellar sort of thing from where I'm writing now; well, if you've ever seen the film "Meet the Parents" my "bunker" is a bit like Jack's cellar, and the funny thing is that I have a cat too (no he's not called Jinx, is a female cat called "SOFIA")
Sergio