The Captain is a 1967 novel by Dutch writer Jan de Hartog. It is a sequel of a sort to his 1940 book Captain Jan, though not having the same characters as the earlier book.
The frame story has Martinus Harinxma, a senior tugboat captain home after a long voyage, catching up on correspondence. He opens a letter from a young man who is the son of a Canadian naval officer killed aboard Harinxma's ship during escort duty during Second World War. In the letter, the son asks the Captain, "How was my father killed, and what was he really like?" As he begins to write the boy, Harinxma is forced to remember, and re-live the events surrounding the Canadian officer's time aboard his ship, and his eventual death.
In 1940 Harinxma, then a young tugboat officer, escapes to Britain. The Kwel company has managed to get away much of its fleet and personnel, one jump ahead of the advancing Germans, and sets up to continue operations from London. Harinxma gets his first command, at an earlier age and under much more difficult conditions than he would otherwise have had.
A central element of the book are the complex relationships between the crew members, in whose depiction de Hartog's personal nautical experience is manifest. Among other things the young and inexperienced captain must face the dilemma of whether to cover up for a severe mishap by the ship's engineer, who is his personal friend, or report him for the sake of the ship's safety and risk his getting fired.
While still being merchant seamen not formally inducted into any navy, Harinxma and his fellow Dutch exile sailors are inexorably sucked into the fighting, their ships given (often inadequate) armaments and sent into some of the hottest arenas of the World War II naval war. Again clearly based on De Hartog's own experience, the book vividly conveys the feeling of suspicion and cordial dislike between the exiled Dutch and their British hosts and allies.
The Dutch sailors feel (and not entirely without reason) that they are being set up as cannon fodder (or rather, U-Boat fodder). Many of Harinxma's fellow Dutch end up on the "South-Western Approaches" to the British Isles, acting as "stretcher-bearers of the sea" in submarine-infested waters - which turns out to be a task involving an extremely high casualty rate. (That experience had formed the background to a previous (1951) de Hartog novel, published variously under the names Stella and The Key and made into a film starring Sophia Loren).