That's about what I found on my boat. My boat had a steel Square D fuse box with the kind of screwed in glass fuses that were popular back in the 1930's. The knock out was removed on the top of the box and that was installed in my lazarette where it could get wet when the
hatch was opened, or small leaves and the like could drop in and did drop in. The 110 system was wired with residential style Romex. The portion that went through the bilge was stained but we could not tell if it was shorted or not. The receptacles lacked ground fault protection as well.
Needless to say I put in a new system when I bought the boat.
Jeff