How ASDIC reshaped anti-submarine ships

Underwater sound detection made a ship's own noise part of the detection problem. Machinery and hull noise could mask a submarine even when the listening equipment worked properly. Hull subdivision and machinery placement therefore needed attention alongside the sensor itself. Later machinery rafting isolated vibration from the hull, while trailing sensors moved the listening equipment away from the ship. Bow-mounted active sonar offered a different arrangement by transmitting a pulse towards a contact. These examples span the wider development of acoustic ship design beyond the Black Swan class.