70 years ago today, on 15 July 1953, Gato-class submarine USS Cavalla (SSK-244) was commissioned for the third time, after her conversion to a hunter-killer submarine. The SSK conversion included remodeling Cavalla's bow with the addition of a curved housing for a BQR-4 sonar system. The conversion included removal of two bow torpedo tubes, along with remodeling the original conning tower and bridge into the sail visible today.
MuseumShip at Galveston Naval Museum, Galveston, TX