U.S. Navy (Courtesy of Bath Iron Works)
The wreckage of Argentina’s TR-1700–class submarine San Juan was located on 17 November 2018 in a 3,000-foot undersea ravine in the Atlantic Ocean, approximately 373 miles east of Comodoro Rivadavia. The missing submarine was found by the seabed exploration and underwater mapping firm Ocean Infinity one 
year and one day after she was lost with all hands. The international search initially was spearheaded by the Argentine Navy before being turned over to the private sector. The discovery followed two months of searching using autonomous underwater vehicles (AUVs) operating from the Texas-based firm’s offshore multipurpose ship Seabed Constructor. The San Juan, pictured here shortly before her loss, was built in Germany and entered service in 1985. She was the newest of Argentina’s three diesel-powered submarines. Displacing 2,100 tons surfaced and 2,350 tons submerged, the 215-foot boat carried a crew of 44 during her final voyage.
(Ignacio Amendolara)
The Norwegian frigate Helge Ingstad was returning from NATO exercise Trident Juncture when she collided with the 62,500-ton Maltese-registered tanker Sola TS off the coast of Norway on 8 November 2018. The collision triggered a series of ill-fated events, ultimately resulting in the sinking of the 5,100-ton Fridtjof Nansen-class frigate. According to a preliminary but ongoing investigation, the collision tore a hole in the frigate’s hull, flooding at least three watertight compartments. The Helge Ingstad was grounded to prevent her loss and later evacuated without any fatalities. Efforts to save the 433-foot frigate, one of the world’s most advanced, proved unsuccessful as support cables that had been holding her in place parted. The warship sank deeper, leaving only her Aegis SPY-1F air-defense radar arrays and foremast still visible above the water. It is unclear at this time whether attempts to salvage the nine-year-old frigate will continue, or whether she will be decommissioned.
Royal Norwegian Ministry of Defence
Mr. Wertheim, a defense consultant in the Washington, D.C., area, is the author of the 16th edition of The Naval Institute Guide to Combat Fleets of the World, available from the Naval Institute Press.