SS-20 Thomson

Oceanic submarine class 209, 1400-L type constructed for the Navy of Chile by the H.D.W. shipyards at Kiel, Germany Federal, since 1980. 07 May 1984 it was released into the water and was hoisted the national flag, being her godmother Doña Berta de Undurraga, and its first Commander, Captain of frigate Román Fritis Pérez. It made landfall at Chile on August 21, 1984, to integrate immediately as one submarine of the force of submarines. Named after the captain of frigate Manuel Thomson Porto Marino, outstanding hero of the Navy who died being Commander of the Monitor Huascar, on February 23, 1880, during the blockade of Arica, in the War of the Pacific. During his 16 years of service, he has participated in 8 Unitas operations, and in 1994, moved to United States and Canada to participate in the "Black" operation, along with units of the navies of these countries more Great Britain, totaling 14.309 miles, of which 11.636 performed submerged.

SS - 21 "Simpson" is an oceanic submarine class 209 type 1300-L constructed for the Navy of Chile by the shipyard Howaldswerke in Kiel, Germany Federal, since 1980. It was delivered in 1984, arriving on August 31, 1984 in Valparaiso. It was renovated in ASMAR Talcahuano shipyard, in 1990.

The Type 209 target environment was the Baltic sea and not the South Pacific sea where the temperature, salinity and depth conditions are quite different. The limited range of the Type 209 is also a major restriction given the large areas to patrol and defend, or the large coastlines to blockade in the event of a major war with any of the potential threats (Argentina and/or Perú). It was easily known when one or both of the Thompson or Simpson was/were in the Beagle Channel because the submarine mother ship Angamos was in the zone.