Crab lice were often a major medical problem aboard U-Boats. One or two crewmen would be infected by prostitutes and because the men had to share bunks, crab lice could quickly spread to all the enlisted men in the boat.
Charles McCain is a Washington DC based freelance journalist and novelist. He is the author of "An Honorable German," a World War Two naval epic. You can read more of his work on his website: http://charlesmccain.com/ View all posts by Charles McCain