Sunfish put to sea again on 22 January 1971 to participate in a short fleet exercise, but her operational commitments changed after she left port and she did not return until 9 March 1971.

Ingalls was owned by Litton Industries at the time, She successfully weathered Hurricane Frederic, which hit the Gulf Coast region.

There were numerous delays, but in early 1980, she completed her sea trials, and was again sent to her homeport at the United States Naval Base, Charleston, South Carolina, after a Caribbean visit to San Juan, Puerto Rico.

Commander Submarine Group 8, Rear Admiral Richard W. Mies, who had served on Sunfish from March 1970 to April 1973, was aboard to give the order to submerge for the history-making dive.

On 4 March 1996, the U.S. Navy's Chief of Naval Information released this story: USS Sunfish (SSN-649) recently reached a milestone few other submarines can claim.

Sunfish stopped briefly in San Diego to offload torpedoes before her final underway to the Puget Sound Naval Shipyard in Bremerton, Washington.

her scrapping via the Nuclear-Powered Ship and Submarine Recycling Program at Puget Sound Navy Yard at Bremerton, Washington was completed on 31 October 1997.