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 a series of Sonar tests against the submarine, which had been altered to have a streamlined hull and increased power to achieve greater submerged velocity, in order to mimic the behavior of German Type XXI or comparable submarines.