At 0840 that morning, "Greer", carrying mail and passengers to Iceland, "was informed by a British plane of the presence of a submerged submarine about 10 miles [(16 km)] directly ahead. . . . Acting on the information from the British plane the "Greer" proceeded to search for the submarine and at 0920 she located the submarine directly ahead by her underwater sound equipment. The "Greer" proceeded then to trail the submarine and broadcast the submarine's position. This action, taken by the "Greer", was in accordance with her orders, that is, to give out information but not to attack." The British plane continued in the vicinity of the submarine until 1032, but prior to her departure the plane dropped four depth charges in the vicinity of the submarine. The "Greer" maintained contact until about 1248. During this period (three hours 28 minutes),the "Greer" manoeuvred so as to keep the submarine ahead. At 1240 the submarine changed course and closed the "Greer". At 1245 an impulse bubble (indicating the discharge of a torpedo by the submarine) was sighted close aboard the "Greer". At 1249 a torpedo track was sighted crossing the wake of the ship from starboard to port, distant about 100 yards [(100 m) astern. At this time the "Greer" lost sound contact with the submarine. At 1300 the "Greer" started searching for the submarine and at 1512 . . . the "Greer" made underwater contact with a submarine. The "Greer" attacked immediately with depth charges.