I have had this problem a few times. The easiest fix was finding the gcfi that was tripped and resetting that. Some of the outlets are fed from those so if they are tripped the outlets being fed will also be off. Another time it was the wires in the back of the outlet just came loose. Be careful taking these off since they dont always go back in easy. some are cheaply mounted so can be a pain to mount flush again. The worst one was on a pup I restored and the wires were chewed by mice. That was just a trial and error on finding the bad section and running new wire.
REMEMBER ... shut off shore power as that can really hurt.
I had the same thing. I pulled the outlet and found that one of the wires had pulled out of the connection on the back. Mine doesn't have screws on the back of the outlets like a home outlet does, the wire simply gets pinched in between the terminal, not a very good design IMHO. if it's not that outlet then look at the one next to it, they usually jump from one to another and that lead wire might have come off instead.
Warning, unplug shore power before doing this... 120VAC is shocking!
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