Highlights of her service for the next few years included testing a new type of submarine escape buoy in January 1948 and again in September 1948; participating in ceremonies at Havana, Cuba, on 14 February 1948, the 50th anniversary of the sinking of the battleship Maine; conversion to a Fleet Snorkel submarine during the first half of 1951; and a starring role in one of Edward R. Murrow's See It Now television shows.

[7] On 15 July 1952, Sablefish broadened her experience by departing New London and proceeding to the Mediterranean Sea for her first deployment with the United States Sixth Fleet.

After exercises with other U.S. warships and vessels of the navies of North Atlantic Treaty Organization (NATO) allies during the rest of the summer, Sablefish returned to New London in October 1952.

When operating on the western side of the Atlantic Ocean, Sablefish was busy with exercises which took her as far north as Nova Scotia, Canada, and south to the Caribbean.

In June 1959, Sablefish was one of the U.S. Navy's representatives at the opening of the St. Lawrence Seaway in Canada, and she operated in the Great Lakes until mid-August 1959.