The Sailfish-class submarines of the United States Navy

United States Navy

The United States Navy is the naval warfare service branch of the United States Armed Forces and one of the seven uniformed services of the United States. The U.S. Navy is the largest in the world; its battle fleet tonnage is greater than that of the next 13 largest navies combined. The U.S...

 were the first to be built expressly for radar picket

Radar picket

A radar picket is a radar-equipped ship, submarine, aircraft, or vehicle used to increase the radar detection range around a force to protect it from surprise attack. Often several detached radar units encircle a force to provide increased cover in all directions.-World War II:Radar picket ships...

service and, at the time, were the largest conventionally powered submarines in the United States Navy. Only the Argonaut submarine (SM-1) and Narwahl class (SS-167 & SS-168) from the 1920s were larger.

Both vessels of this class were commissioned in 1956, and served until the late 1970s.