Unlike the other four ships eventually in the Q-ship program, "Captor" did not sail in convoys or along coastal shipping routes. Instead, she operated in the waters near Boston – in Massachusetts Bay, north to Casco Bay, east to the Georges Bank, and south to Nantucket Sound and Rhode Island Sound. While at sea, the disguised Q-ship also helped cover the coastal convoy routes coming north from New York. As growing air and sea patrols had driven most U-boats away from the New England coast in May 1942, "Captor" had little chance to spot an enemy submarine and ended her wartime career without a single sighting.