The USS Kraken (SS-370) was a Balao Class, Perch Variant, diesel-electric submarine. She was built in Manitowoc, WI in 1944. and was commissioned in Sept of that year.
She was converted to Fleet Snorkel in 1959 and loaned to Spain later, that same year. [Admirante Garcia de los Reyes (S-31)] She was finally returned and, then, sold to Spain, in 1974.
More info, and pictures, can be found on the Navsource Submarine index.
<< http://www.navsource.org/archives/subidx.htm >>