In September 1944, Kingfisher carried out a series of Sonar trials against the submarine , which had been modified with a streamlined hull and higher power to give greater submerged speed, in order to simulate the behaviour of the German Type XXI or similar submarines.
In September 1944, Kingfisher conducted Sonar trials against the submarine, which had been modified with a streamlined hull and increased power to achieve greater speed underwater, comparable to that of German Type XXI or similar vessels.