Exercise Atlantic Thunder 2026

Ships, aircraft, and a submarine from the US and UK were involved in Exercise Atlantic Thunder 2026, a multi-domain sinking exercise (SINKEX) led by US 6th Fleet, in the North Atlantic, Sep. 25, 2026.

According to a US Navy news release, during the SINKEX, participating forces assigned to U.S. Commander, Task Force 65, US Commander, Task Force 67, US Commander, Task Force 68, US Commander, Task Force 69 and US Commander, Task Force 1060 alongside the UK Royal Navy and the US Air Force sank the decommissioned guided-missile frigate ex-USS Klakring. The event developed combined proficiency in tactics, targeting, and live-firing against a surface target at sea.

“Atlantic Thunder demonstrates the unmatched lethality and interoperability of the United States and United Kingdom,” said US Capt. Kelechi Ndukwe, Commander, U.S. Task Force 65. “This sinking exercise not only validated the power behind U.S.-UK offensive weapons but delivers a clear message to adversaries that the U.S. Navy and Royal Navy remain a ready allied force.”

The exercise strengthens the US-UK alliance, warfighting credibility, and interoperability during long-range maritime sinking operations. During the SINKEX, the guided-missile destroyer USS Paul Ignatius (DDG 117) successfully demonstrated maximum damage and range capability of an anti-surface variant of the Standard Missile 6 (SM-6). USS Massachusetts (SSN 798) successfully engaged the target with the Mk 48 Advanced Capability Torpedo, resulting in the final hit and ultimately sinking ex-USS Klakring, as the video in this post shows.

US and UK units involved in the exercise

During the exercise, the Royal Navy confirmed its newest ship-busting missiles, the Naval Strike Missile (NSM) and Sea Venom.

“The successful firing of NSM marks a significant milestone for the Royal Navy, demonstrating our ability to deliver credible, modern maritime strike capability,” said Royal Navy Lt. Cmdr. Louise Kirkaldy, HMS Portland’s Principal Warfare.

Prior to the start of the exercise Naval Surface Warfare Center Carderock and Naval Information Warfare Center (NIWC) Pacific used sensors placed on the target ship to perform battle damage assessments. The data gathered will be used in post-exercise damage assessments to provide critical information to rapidly identify system failures, determine repair needs, and strengthen the Navy’s future real-world response.

US and UK units involved in the exercise included Paul Ignatius, USS Massachusetts, Royal Navy frigate HMS Portland (F 79), US Navy and Royal Air Force P-8 maritime patrol aircraft, a Royal Navy Wildcat helicopter, US Air Force F-15E Strike Eagles, and personnel assigned to US Explosive Ordnance Disposal Mobile Unit (EODMU) 8.

USS Klakring

USS Klakring (FFG-42) was a Oliver Hazard Perry class frigate of the United States Navy named for Rear Admiral Thomas B. Klakring (1904–1975), who was awarded three Navy Crosses as commander of the submarine USS Guardfish during World War II.

Klakring was laid down on 19 February 1982 by the Bath Iron Works Corp. Bath, Maine; launched on Sep. 18, 1982, sponsored by Beverly Bohen, niece of Rear Admiral Klakring, and commissioned on Aug. 20, 1983 at Bath.

The USS Klakring was decommissioned on Mar. 22, 2013.

Hulks

Former US Navy vessels used in SINKEXs, referred to as hulks, are prepared in strict compliance with regulations prescribed and enforced by the Environmental Protection Agency under a general permit the Navy holds pursuant to the Marine Protection, Research and Sanctuaries Act.

Prior to being transported, each hulk undergoes a rigorous cleaning process for environmental safety. Aligned with UK Ministry of Defense environmental policy, robust monitoring was conducted above and below the sea’s surface with trained personnel using specialized equipment to reduce the overall risk of inadvertent impact to the marine environment and marine mammals during the Atlantic Thunder 2026 SINKEX.

Photo credit: U.S. Navy and Royal Navy

Video: VIDEO: Former U.S. Frigate Sunk in Exercise with U.S., Royal Navies Dzirhan Mahadzir September 30, 2026 1:27 PM

SM-6, Sea Venom, and Naval Strike Missile munitions were paired alongside a Mark 48 ADCAP torpedo to send the decommissioned Oliver Hazard Perry class frigate to the bottom of the Atlantic Ocean. 

Concluding Exercise Atlantic Thunder 2026, the sink exercise (SINKEX) was conducted in the Northern Atlantic off the Outer Hebrides in Northern Scotland. The former USS Klakring, an Oliver Hazard Perry class frigate commissioned in 1983 and decommissioned in 2013, was specially prepared for the exercise with extensive cleaning and hazard removal. 

The SINKEX was used to validate the capabilities of a number of new munitions which have entered service in recent years. Arleigh Burke class guided missile destroyer USS Paul Ignatius (DDG 117) fired an SM-6 missile in its secondary role as an anti-ship weapon, testing the performance of the missile towards the upper end of its range. 

Decommissioned Oliver Hazard Perry-class frigate USS Klakring (FFG-42) being towed out of Philadelphia Naval Inactive Ship Maintenance Facility (NISMF) for SINKEX reportedly around Scotland – August 12, 2026 SRC: FB- Delaware River Shipping / John Curdy pic.twitter.com/y5JIvPBLVu

— WarshipCam (@WarshipCam) August 13, 2026

“Atlantic Thunder demonstrates the unmatched lethality and interoperability of the United States and United Kingdom,” said Captain Kelechi Ndukwe, Commander, U.S. Task Force 65. “This sinking exercise not only validated the power behind U.S.-UK offensive weapons but delivers a clear message to adversaries that the U.S. Navy and Royal Navy remain a ready allied force.”

New onboard SINKEX views — including some wild slo-mo

US-UK forces send the decommissioned guided-missile frigate USS Klakring to the bottom of the Atlantic

Blows delivered by USS Paul Ignatius, the newly commissioned USS Massachusetts, others

(Compiled by MC1 Austin Ingram) pic.twitter.com/cS8Ok1O3Nc

— J.D. Simkins (@simkins_jd) September 29, 2026

Royal Navy Type 23 frigate HMS Portland (F79) used the opportunity to conduct the service’s first ever ‘warshot’ launch of the Norwegian-built Naval Strike Missile (NSM) that has replaced the Harpoon in UK service. Petty Officer James Kenyon, an Above Water Warfare specialist on HMS Portland, said: “Being the first person to fire war-shot NSM and achieve a hit is a very proud moment, and one that will stay with me for the rest of my career. This was the culmination of over a year’s effort in planning and bringing the drills into service, and I am glad that I was able to contribute.”

Lieutenant Commander Louise Kirkaldy, Portland’s Principal Warfare Officer (PWO), said: “The successful firing of NSM marks a significant milestone for the Royal Navy, demonstrating our ability to deliver credible, modern maritime strike capability.”

HMS Portland launches a Naval Strike Missile during Exercise Atlantic Thunder off Scotland, striking the decommissioned USS Klakring in the Royal Navy’s first operational firing of NSM.

LPhot Henry Parks / Royal Navy pic.twitter.com/mvZUh7NLSU

— UK Defence Journal (@UKDefJournal) September 29, 2026

Portland’s contribution was added to by the ship’s embarked Wildcat helicopter, hailing from 815 Naval Air Squadron. In another first, the Wildcat fired a Sea Venom anti-ship missile at the Klakring in the first operational live firing of the weapon type against a realistic target. 

A Wildcat helicopter can carry as many as four Sea Venom missiles per sortie, with each weapon packing a 120 kilogram warhead. Though much smaller than ship-killing weapons like NSM and Harpoon, the Sea Venom is designed to deliver enough destructive capability to destroy smaller naval vessels, or using multiple finely targeted missiles complete a successful mission kill against larger frigate or destroyer sized targets. 

Lieutenant Commander Rhydian Edwards, Test & Evaluation Commander, Maritime Aviation Strike Operational Advantage Group, said: “This was a landmark moment for the Wildcat Force. For the first time we demonstrated the live firing of an operational Sea Venom missile against a representative maritime target. More importantly, we proved our ability to execute the full maritime strike kill chain under realistic operational conditions.”

“This was about giving commanders confidence that Wildcat can find, fix and strike maritime targets using Sea Venom as part of a wider task group. The lessons learned from this activity will directly inform future tactics, training and operational capability development, ensuring Maritime Aviation Strike remains ready to fight and win when called upon.”

More air-launched munitions came in the form of guided bombs dropped by F-15E Strike Eagles based with the 48th Fighter Wing (FW) at RAF Lakenheath. P-8 Poseidon maritime patrol aircraft from the U.S. and UK also took part in the SINKEX, though no weapon launches have been attributed to them and their contribution may have simply been as surveillance platforms. 

Finishing off the Klakring, the USS Massachusetts (SSN 798), commissioned into the U.S. Navy in March 2026, targeted the frigate with a Mark 48 Advanced Capability (ADCAP) torpedo. 

USS Massachusetts (SSN 798) Virginia-class Block IV attack submarine leaving Faslane, Scotland – September 11, 2026 SRC: FB- Argyll Sea Glass pic.twitter.com/Ba4k7jzjyJ

— WarshipCam (@WarshipCam) September 11, 2026

Massachusetts, the 25th Virginia class submarine, was pushed into service without the traditional post-commissioning shakedown period in order to mitigate current shortfalls in U.S. attack submarine availability. The decision has been described as a ‘calculated risk’. The submarine was noted at the Royal Navy’s Faslane base earlier in September.

© U.S. Navy, Royal Navy