ARA San Juan (S-42)

The ARA San Juan (S-42) was a TR-1700-class diesel-electric submarine of the Argentine Navy. Built by Thyssen Nordseewerke in Emden, Germany, it was commissioned in 1985. The San Juan underwent a mid-life modernization program between 2008 and 2014.

On 15 November 2017, while en route from Ushuaia to Mar del Plata, the San Juan went missing in the South Atlantic Ocean. An international search and rescue operation was launched, involving numerous countries and assets.

After an extensive search, wreckage of the San Juan was located on 17 November 2018, approximately 400 kilometers (250 miles) off the coast of Argentina at a depth of 920 meters (3,018 feet). All 44 crew members perished.

An official investigation determined that the sinking was likely caused by seawater entering the ventilation system while the submarine was snorkeling, leading to a short circuit and a subsequent fire in the battery compartment. This event triggered a catastrophic implosion.

The loss of the ARA San Juan resulted in significant national mourning in Argentina and led to considerable scrutiny of the Argentine Navy's maintenance practices and resource allocation. The incident highlighted the challenges of operating and maintaining older submarines and the inherent risks of submarine service.