The Almirante García de los Reyes was launched as USS Kraken in 1944. She sailed four war patrols, sinking several japanese targets. After the war, USS Kraken remained in reserve status until 18 September 1958, when she was assigned to Pearl Harbor Naval Shipyard for activation overhaul and given a Fleet Snorkel conversion preparatory to transfer on loan to Spain. After several months of familiarization at Pearl Harbor for her new crew, on 25 October 1959 she was commissioned in the Spanish Armada as Almirante García de los Reyes, in memory of Don Mateo García de los Reyes (1862–1936), the Spanish Navy's pioneer in submarines.
Upon arrival in Spain, she immediately became the best boat (and almost the only operating) in the "Arma Submarina". She was humorously called "El Treintayúnico" (could be translated as "the Thirtyonly"). With her came to Spain the first snorkel, guided torpedoes, the first submarine sonar ... in short, she meant a huge jump from the German technology of the early forties (the G-7, ex U-573).
The operating life of S-31 was stressless, primarily engaged in training duties for her own crews and surface ships (finally, there was a submarine that could pose a real threat to antisubmarine vessels). The S-31 should have been retired in the mid 70's, but the lack of modern submarines in the Armada forced to extend her life until 1982, when she was replaced by the first boat of the S-70 series.
I kitbashed de 1/700 Balao Class Hobby Boss kit. It is a very nice and cheap kit. Sadly it represents a Balao class sub in her war fit, so I had to build the sail from scratch. Anyway it was a fast and relaxing build.