Both boats were launched in 1935, and they saw action in the Spanish Civil War and the Second World War. Glauco was badly damaged by the British destroyer HMS Wishart and scuttled by her own crew on 27 June 1941, west of Gibraltar; Otaria was surrendered to the Allies in 1943 and used for training until it was sent to the junkyard in 1948.
Both boats were constructed in 1935 and saw combat during the Spanish Civil War and World War II. Glauco suffered severe damage from HMS Wishart and was scuttled by its crew on June 27, 1941, west of Gibraltar; Otaria was surrendered to the Allies in 1943 and used for training before being sent to a scrapyard in 1948.