I'd imagine the power strip wasn't up to the amperage.
About the only thing electrical I'll leave running on a boat is a charger. And then I would rarely leave it overnight, and only when the boat was on jackstands. I can't imagine leaving any sort of heater running on a boat unattended, even an electric heater, now that Westie mentioned his experience. But I always assume people leave there boats and go home when they're done sailing.