I am familiar with a boat (not mine, much more of a "yacht") that routinely carries firearms (rifles, so not easily concealed) aboard while in Mexican and other foreign (to US) waters in which guns are highly illegal. They put their guns behind a false panel in the engine room, with what looks like lots of high voltage wiring in front of it (subtly marked "peligro" with a lightning bolt symbol). They said no one ever wants to poke around in there, but with the guns, they have about $15K in cash (small bills, so it looks like more than it is), the theory being that if someone does see it they will take the cash and keep their mouths shut).
I would also suggest two safs, one (much easier to find than the other) being a decoy safe. But I have not yet implemented that -- I only have one safe. The truth is, if a thief were to take my reels and stidd chairs, I would probably have to file BK. I would rather that they take the safe.
Reminds me of the time that my wife's credit card got stolen. The thing is the thief spent less than she did, so I never reported it.