The wire color codes are all wrong. Did someone use surplus wire to save money? Was this boat built in some foreign country?

These colors will confuse any electrician working on the boat.

The U.S. NEC (national electric code uses green for ground, white for neutral and black for hot.

It sure sounds like the wiring is wrong. Off hand I do not know which pin is which but again, by convention, the ground pin will have a green screw, the neutral will have a silver screw and the hot will have a brass screw. They will also be labeled per the color (W for white, etc.). Your best bet is to buy a $5 polarity checker at any home improvement store and plug it into any outlet.

I would also suggest that if you intend to keep that wire that you wire each and every termination point with a wire marker to signify what you have designated each wire to be.

BTW: In most of the 220Volt/50Hz world yellow/green is ground and the other two wires are brown and blue.