 As was the case with the other Norwegian torpedo boat units, the vessels of the 4th Torpedo Boat Division operated individually along the coast, protecting Norwegian shipping and guarding against neutrality violations.During the first months of the war Norwegian neutrality was repeatedly breached by both warring sides, most dramatically by the Royal Navy in the February 1940 Altmark Incident.On 29 September 1939, the Norwegian merchant navy suffered its first loss to a U-boat, when the England-bound was stopped by the German U-boat and torpedoed and shelled after the crew abandoned ship.