The
VHF and a quiet night watch on the open sea is a situation fraught with possibilities. I've detailed one or two of those elsewhere but suffice it to say that answering a very persitent, or obtuse,
radio caller as the station he's trying to reach can be rather entertaining-especially if you have them keep switching channels.
Surprising someone, or vessel, that doesn't know you're there can be fun if you like Chinese fire drills and you're on an 80,000 ton tanker and they're on a sailboat in the middle of the ocean. The ship's horn has a galvinizing effect on them.
Dead and slimy fish placed under the covers of the bunk can produce amazing feats of self-propulsion.
A piece of mushroom, canned seems to have the best texture, placed in the night watch's coffee mug get's great results, albeit in the dark. There's just something about something slimy in your mouth when you cannot see what it is that makes the imagination go wild.
Placing any kind of marbles within a confined space, such as an overhead, will generally induce insanity in whomever's sleeping area it is within an hour. If on a boat, you don't put them in a drawer-you put them
behind a drawer! Similarly, you may hang something over the side that will regularly bump the hull as the boat works, which you remove as you hear them coming on deck to investigate. If you can carry it off to where they come topside three times and not suspect you you'll be worthy of an Oscar.