I have one sitting right behind me as I type this about 30 miles north
of Ketchikan enroute to Juneau. The boat is gently rolling and the stuff
in the fridge is nice and cool as it has been for the couple of years
the "dorm" fridge has been mounted here.

I have used them on TransPacs when it was so rough they were airborne
half the time and they still worked fine as they spilled ice cold stuff
all over the place.

Rick