On 15 November 2017, the Argentine submarine ARA San Juan disappeared in the South Atlantic off the coast of Argentina while on a training exercise.

On 16 November 2018, a year after the disappearance of the submarine, her wreck was found in the South Atlantic by the private company Ocean Infinity[2] at a depth of 907 metres (2,976 ft) at 45°56′59″S 59°46′22″W / 45.94972°S 59.77278°W / -45.94972; -59.77278.

[6][7] With the war game completed and after a short visit to Ushuaia open to the public, the submarine got underway to her home base at Mar del Plata.

[12][11] On the same day, Argentine president Mauricio Macri moved to the official residence at Chapadmalal, near Mar del Plata, in order to follow the search and rescue operation more closely.

[16] On 18 November, the Ministry of Defense reported that there had been attempts at communication that day from a satellite phone that was believed to be from the submarine,[17][18] but it was later determined that the calls were not from the vessel.

[12][21] The Argentine Navy later reported that sonar systems on two of its ships and sonar buoys dropped by a US P-8A Poseidon aircraft detected noises possibly coming from San Juan; a senior United States Navy officer told CNN that this sounded like banging on the hull in order to alert passing ships;[21][22][23] later analysis of the audio determined that the sound "did not correspond to a submarine", and was probably of biological origin.

[25] The Royal Navy stated that 10-metre (33 ft) waves had slowed the search, but easing weather led to improved sonar conditions.

[27] The United States Navy later reported that one of its planes had detected a heat signature which corresponded to a metallic object at a depth of 70 metres (230 ft), 300 kilometres (190 mi) off the coast of Puerto Madryn.

In all, more than 4,000 personnel from 13 countries assisted the search, scouring some 500,000 square kilometres (190,000 sq mi) of ocean – an area the size of Spain.

[40] On 26 November, the Argentine Navy said that "despite 11 days of searching, it doesn't rule out that [the crew] could be in an extreme survival situation" and were not willing to draw any conclusions until the submarine had been located.

[43] On 30 November, 15 days after San Juan went missing, the Navy declared the rescue part of the operation to be over, turning its attention to finding the submarine and not her crew.

[1] The incident is also the second worst naval disaster in Argentina during peacetime after the loss of the minesweeper ARA Fournier with her complement of 77 off Tierra del Fuego on 22 September 1949.

[64][65][66] It had been considered that the probability of locating the wreck in the area where it was eventually found was 90%, but previous searches failed to find it due to inadequate technology and presence of numerous submarine canyons.

The pictures show the imploded pressure hull, with the bow section, sail and propellers scattered in an area of 8,000 square metres (86,000 sq ft).

[74] On 24 October 2021 a monument commemorating the 44 crew members lost was unveiled in front of the Mar del Plata Naval Base.