The Sailfish-class submarines of the United States Navy were the first to be built expressly for radar picket service and, at the time, were the largest conventionally powered submarines in the United States Navy. Only the USS Argonaut (SM-1) and Narwhal-class submarines from the 1920s were larger. The Sailfishes were initially equipped with large BP2-2 and BPS-3 radars in and aft of the sail. They were designed for a high surface speed; however, their speed achieved was not significantly faster than converted World War II radar picket submarines. Commissioned in 1956, they served in the radar picket role until early 1961, when the submarine radar picket mission ended fleetwide. Airborne radar had superseded it with the full deployment of the Grumman WF-2 Tracer. Modernized under the Fleet