The photo description says:
A starboard quarter view of the Colombian submarine PIJAO (S 28) underway off Cartagena, Columbia, during Operation UNITAS XXV.
One of the two Ocean Submarines owned by the ARC type U-209 / A-1200 The Submarines baptized as "ARC Pijao" (SO-28) and "ARC Tayrona" (SO-29) were built by Howaldtswerke-Deutsche-Werft AG (HDW) in Kiel between 1972 and 1974 and delivered to the Navy Republic of Colombia in 1975. From that date, the Colombian Submarines have been the subject of two modernization programs in Germany. The Type 209 / A-1200 have a length of 56.1 meters, a beam of 6.2 meters and a depth of 5.5 meters. The displace 1,200 tons and have a crew of 34 sailors, with diesel-electric propulsion.
The U-209 is based on the U-206, but has dimensions much larger and unlike that has the capacity to operate in the ocean and autonomy to move over long distances. Although generically called U-209 per share largely a common concept, there are actually several series of submarine U-209 which differ among themselves, some being easily identifiable externally.
The U-209 is a submarine that can be configured according to the requirements and needs of customers and hence it resulted that all series have differences. The various sets are divided as follows: 1000/1100, 1200, 1300, 1400 and 1500. The countries that operate the various classes of submarines Type 209 are: Armada Argentina, Brazil, Chile Navy, Army of the Republic of Colombia, Ecuador, Greece, Indonesia, Navy of Peru, South Africa, South Korea, Turkey and Navy of the Bolivarian Republic of Venezuela.
Class Submarines Pijao Type 209/1200 of the Colombian Navy (ARC), underwent a process of modernization in COTECMAR; ARC Tayrona entered in mid-2009 and ARC Pijao a year later, with technical assistance from HDW.
https://www.globalsecurity.org/military/world/colombia/arc-pijao.htm