US and UK forces sink decommissioned USS Klakring during Atlantic Thunder 26

United States and United Kingdom forces concluded Exercise Atlantic Thunder 26, a multi-domain sinking exercise (SINKEX) in the North Atlantic. On September 25, 2026, the decommissioned US Navy Oliver Hazard Perry-class frigate USS Klakring was sunk in the Hebrides Range, approximately 150 nautical miles off the coast of Scotland.

The exercise involved coordinated strikes from air and surface assets to test advanced weaponry and interoperability. Key participants included the US Navy destroyer USS Paul Ignatius, the nuclear-powered submarine USS Massachusetts, and the Royal Navy frigate HMS Portland. The sinking validated several missile systems, including the Royal Navy’s first operational firing of the Naval Strike Missile (NSM) and the Sea Venom missile launched from a Wildcat helicopter. The US also utilized the SM-6 missile.

The USS Klakring, which was decommissioned in 2013, was towed from Philadelphia to Scotland as part of a cost-sharing agreement between the two nations. Officials stated that the vessel underwent rigorous cleaning to meet environmental regulations and is expected to serve as a natural reef at a depth of approximately 1,800 to 1,900 metres. Following the sinking, uncrewed underwater vehicles are planned to survey the wreckage to assess structural damage and the impact of the firepower.