boat proctologist
n.— «One Dutch Harbor resident, Jeff Whited, who calls himself a “boat proctologist”—that is, someone who goes down into the bowels of a vessel to fix an engine or a prop shaft—said, “I hate these movie stars” while working on the Northwestern, Captain Hansen’s boat.» —“Commercial Fishermen, Battling the Elements Between Commercials” by Charles McGrath in Unalaska, Alaska New York Times Apr. 6, 2008. (source: Double-Tongued Dictionary)