Unsworth was the chief mate aboard the Isabella who once sailed on the Henrietta.
Feeling that he deserved the ship rather than Captain Alexander Marfleet, he exploited Captain Marfleet's superstitious beliefs by having his former crew-mates pose as the Flying Dutchman and led a mutiny against him. However, he was exposed thanks to the Seventh Doctor and demoted, replaced as Chief Mate by Anna. (AUDIO: The Flying Dutchman)