The Barbel-Class
Laid down by Ingalls Shipbuilding Corporation of Pascagoula, Mississippi in April 1957 and launched in May 1959, SS-581 was the final non-nuclear submarine to enter service in the U.S. Navy and was truly the last of her kind. Serving until October 1990, she was also the final conventionally-powered combat-capable submarine to be decommissioned.

USS Blueback was also notable for being just one of three Barbel-class boats to be constructed, but she is also the only of the three to be maintained as a museum ship.
The class was notable in that it actually incorporated numerous, even radical engineering improvements over the previous diesel-electric subs, including the first to be built with the “teardrop-shaped” hull that had been tested on the USS Albacore (AGSS-569), as well as the first to feature a single propeller. The hull design was critical in that it increased underwater speed dramatically while it also enabled the submarine to be far more maneuverable. Additionally, the Barbel-class utilized a combined control room, attack center, and conning tower in the same space in the hull.
Barbel-Class: Notable Blueback Accomplishments
During her 31 years in service with the U.S. Navy, USS Blueback participated in Pacific Fleet operations, which included a transiting of the Panama Canal. In September 1961, she also set a record by traveling 5,340 miles from Yokosuka, Japan to San Diego entirely submerged.
The submarine also earned two battle stars for her service in the Vietnam War.
Shortly before her decommissioning in 1990, USS Blueback was provided by the U.S. Navy for use in the film The Hunt for Red October, based on the Tom Clancy novel of the same name. In the movie, she stood in for a Soviet submarine, while a film crew was allowed to film in the torpedo room, with some of her crew even said to have been paid to wear Soviet Navy uniforms! It wasn’t the first pop-culture appearance for the submarine, as SS-581 had previously appeared in the 1970s TV series Hawaii Five-O.