Task: Question Answering
Input (English): Passage: The film begins with Thomas "Boats" Gilhooley ("boats" is a nickname for a bosun's mate) (Lee Marvin), an expatriate United States Navy veteran, working aboard a freighter. When he realizes that the ship is passing by Haleakaloha, French Polynesia, but not actually calling there, he jumps ship to swim to the island.
Next, Michael "Guns" Donovan ("guns" is a Navy nickname for a gunner's mate), another expatriate U.S. Navy veteran and a former shipmate of Gilhooley, returns from a fishing trip aboard an outrigger canoe. Donovan is greeted by William "Doc" Dedham, also a U.S. Navy veteran and the only physician in the archipelago, who is about to begin a one or two week pre-Christmas circuit of the "outer islands," taking care of the health needs of the residents. Dedham's three children are placed in Donovan's care.
The kids' plans for a peaceful celebration of Donovan's birthday on December 7 are shattered by the arrival of Gilhooley, who shares his birthday. There is an unbroken 21-year tradition that Donovan and Gilhooley have a knock-down, drag-out fight every birthday—-to the delight of the local observers-—and their 22nd year does not break the tradition. The two vets meet in (and trash) "Donovan's Reef," the saloon owned by Donovan.
Miss Amelia Dedham is a "proper" young lady "of means" from Boston, who has become the chairman of the board of the Dedham Shipping Company. Her father is Doc Dedham, whom she has never met, but who now has inherited a large block of stock in the family company, making him the majority stockholder. She travels to Haleakaloha in hope of finding proof that Doc has violated an outdated (but still in effect) morality clause in the will which would keep him from inheriting the stock and thus enable her to retain control. 
Question: What is the nickname of the person about to take a trip to the outer islands?
Output (English): Doc.