The U-65 was supposed to be haunted and/or cursed after various crewmen
and construction workers were killed in accidents. The only ghost seen was
a crew member who got killed when a torpedo fell out of its sling while
being loaded. While this is obviously the result of good story-telling during
boring parts of a cruise, the official reports do not verify the story (as one
crackpot site claims).

This WW1 U-boat made 51 patrols, sinking 52 ships, and was scuttled to
avoid capture.

It is not true that after being sighted by an American sub, the American
commander ordered several sailors to check through the periscope to make
sure that he had the right number, and then the sub blew up without being
fired upon. That's the kind of nonsense you find in "true" ghost stories.

One site tells the story of the haunted U-boat right after a story about a pond
in England that is haunted by the ghost of a chicken that Sir Francis Bacon
stuffed with snow.

I am unable to find any information as to whether there were an unusually
large number of fatal accidents on the sub.

One site insists that since the Germans had a priest exorcise the U-65, the
German high command believed the ship was haunted. Actually, the
German high command would only have wanted to allay the crew members'
fears, if the story about the exorcism is true.

Different stories give different numbers of sailors who went insane after
talking to the ghost (who actually seemed to be a nice fellow, and only
wanted to chat).

The ghost stories contradict each other for a good reason: there are no facts
or records to use as a source of the haunting.