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U.S., Republic of Korea conduct Maritime Counter Special Operations Forces Exercise

21 November 2025

From Lt. Victor Murkowski, Destroyer Squadron 15

The U.S. Navy and Republic of Korea (ROK) Navy conducted a Maritime Counter Special Operations Forces Exercise (MCSOFEX) in Pyeongtaek, Republic of Korea, and its surrounding waters and airspace, Nov. 17-20.

The Republic of Korea (ROK) Navy Chungmugong Yi Sun-sin-class destroyer ROKS Wang Geon (DDG 978), left, and Daegu-class frigate ROKS Daejeon (FFG 823), right, sail in formation aft of Arleigh Burke-class guided-missile destroyer USS Dewey (DDG 105) during the Maritime Counter Special Operations Exercise (MCSOFEX) with the ROK Navy, Nov. 18, 2025.
AT SEA (Nov. 18, 2025) – The Republic of Korea (ROK) Navy Chungmugong Yi Sun-sin-class destroyer ROKS Wang Geon (DDG 978), left, and Daegu-class frigate ROKS Daejeon (FFG 823), right, sail in formation aft of Arleigh Burke-class guided-missile destroyer USS Dewey (DDG 105) during the Maritime Counter Special Operations Exercise (MCSOFEX) with the ROK Navy, Nov. 18, 2025. Dewey is forward-deployed and assigned to Destroyer Squadron (DESRON) 15, the Navy’s largest DESRON and the U.S. 7th Fleet’s principal surface force. MCSOFEX is an exercise that promotes regional security cooperation, maintains and strengthens alliances, and enhances interoperability with the ROK Navy. (U.S. Navy photo by Mass Communication Specialist 2nd Class Oscar Diaz).
The Republic of Korea (ROK) Navy Chungmugong Yi Sun-sin-class destroyer ROKS Wang Geon (DDG 978), left, and Daegu-class frigate ROKS Daejeon (FFG 823), right, sail in formation aft of Arleigh Burke-class guided-missile destroyer USS Dewey (DDG 105) during the Maritime Counter Special Operations Exercise (MCSOFEX) with the ROK Navy, Nov. 18, 2025.
251118-N-JJ672-1331
AT SEA (Nov. 18, 2025) – The Republic of Korea (ROK) Navy Chungmugong Yi Sun-sin-class destroyer ROKS Wang Geon (DDG 978), left, and Daegu-class frigate ROKS Daejeon (FFG 823), right, sail in formation aft of Arleigh Burke-class guided-missile destroyer USS Dewey (DDG 105) during the Maritime Counter Special Operations Exercise (MCSOFEX) with the ROK Navy, Nov. 18, 2025. Dewey is forward-deployed and assigned to Destroyer Squadron (DESRON) 15, the Navy’s largest DESRON and the U.S. 7th Fleet’s principal surface force. MCSOFEX is an exercise that promotes regional security cooperation, maintains and strengthens alliances, and enhances interoperability with the ROK Navy. (U.S. Navy photo by Mass Communication Specialist 2nd Class Oscar Diaz).
Photo By: Petty Officer 2nd Class Oscar Diaz
VIRIN: 251118-N-JJ672-1331

 
This year’s second iteration of MCSOFEX encompassed four days of enhanced bilateral training, focusing on naval interoperability and collaboration to address shared maritime security challenges in the Indo-Pacific. MCSOFEX follows the trilateral Freedom Edge exercise between the U.S., Japan, and ROK navies.
 
Participating U.S. assets were U.S. Navy Arleigh Burke-class guided-missile destroyer USS Dewey (DDG 105), one MH-60R Seahawk helicopter, two U.S. AH-060E Apache helicopters, and one U.S. P-8A Poseidon.
 
“MCSOFEX is just a part of our continuous exercises with our ROK counterparts,” said Capt. Dave Huljack, commodore of Destroyer Squadron (DESRON) 15. “Through exercises like MCSOFEX, Freedom Edge, Ulchi Freedom Shield, and numerous others, we continue to enhance our shared interoperability between the U.S. and ROK navies and our allies and partners to ensure a free and open Indo-Pacific.”

U.S. Navy and Republic of Korea Navy (ROK) Sailors discuss maneuvers aboard Arleigh Burke-class guided-missile destroyer USS Dewey (DDG 105) during the Maritime Counter Special Operations Exercise (MCSOFEX) with the ROK Navy, Nov. 18, 2025.
251118-N-JJ672-1319 AT SEA (Nov. 18, 2025) – U.S. Navy and Republic of Korea Navy (ROK) Sailors discuss maneuvers aboard Arleigh Burke-class guided-missile destroyer USS Dewey (DDG 105) during the Maritime Counter Special Operations Exercise (MCSOFEX) with the ROK Navy, Nov. 18, 2025. Dewey is forward-deployed and assigned to Destroyer Squadron (DESRON) 15, the Navy’s largest DESRON and the U.S. 7th Fleet’s principal surface force. MCSOFEX is an exercise that promotes regional security cooperation, maintains and strengthens alliances, and enhances interoperability with the ROK Navy. (U.S. Navy photo by Mass Communication Specialist 2nd Class Oscar Diaz).
U.S. Navy Sailors and Republic of Korea (ROK) Navy Sailors collaborate on the bridge aboard Arleigh Burke-class guided-missile destroyer USS Dewey (DDG 105) during the Maritime Counter Special Operations Exercise (MCSOFEX) with the ROK Navy, Nov. 18, 2025.
251118-N-JJ672-1338 AT SEA (Nov. 18, 2025) – U.S. Navy Sailors and Republic of Korea (ROK) Navy Sailors collaborate on the bridge aboard Arleigh Burke-class guided-missile destroyer USS Dewey (DDG 105) during the Maritime Counter Special Operations Exercise (MCSOFEX) with the ROK Navy, Nov. 18, 2025. Dewey is forward-deployed and assigned to Destroyer Squadron (DESRON) 15, the Navy’s largest DESRON and the U.S. 7th Fleet’s principal surface force. MCSOFEX is an exercise that promotes regional security cooperation, maintains and strengthens alliances, and enhances interoperability with the ROK Navy. (U.S. Navy photo by Mass Communication Specialist 2nd Class Oscar Diaz).
U.S. Navy Quartermaster 2nd Class Tyler Northern stands watch aboard Arleigh Burke-class guided-missile destroyer USS Dewey (DDG 105) during the Maritime Counter Special Operations Exercise (MCSOFEX) with the Republic of Korea (ROK) Navy, Nov. 18, 2025.
251118-N-JJ672-1212 AT SEA (Nov. 18, 2025) – U.S. Navy Quartermaster 2nd Class Tyler Northern stands watch aboard Arleigh Burke-class guided-missile destroyer USS Dewey (DDG 105) during the Maritime Counter Special Operations Exercise (MCSOFEX) with the Republic of Korea (ROK) Navy, Nov. 18, 2025. Dewey is forward-deployed and assigned to Destroyer Squadron (DESRON) 15, the Navy’s largest DESRON and the U.S. 7th Fleet’s principal surface force. MCSOFEX is an exercise that promotes regional security cooperation, maintains and strengthens alliances, and enhances interoperability with the ROK Navy. (U.S. Navy photo by Mass Communication Specialist 2nd Class Oscar Diaz).
The Republic of Korea (ROK) Chungmugong Yi Sun-sin-class guided-missile destroyer ROKS Wang Geon (DDG 978) travels aft of Arleigh Burke-class guided-missile destroyer USS Dewey (DDG 105) during the Maritime Counter Special Operations Exercise (MCSOFEX) with the ROK Navy Nov. 18, 2025.
251118-N-JJ672-1259 AT SEA (Nov. 18, 2025) – The Republic of Korea (ROK) Chungmugong Yi Sun-sin-class guided-missile destroyer ROKS Wang Geon (DDG 978) travels aft of Arleigh Burke-class guided-missile destroyer USS Dewey (DDG 105) during the Maritime Counter Special Operations Exercise (MCSOFEX) with the ROK Navy Nov. 18, 2025. Dewey is forward-deployed and assigned to Destroyer Squadron (DESRON) 15, the Navy’s largest DESRON and the U.S. 7th Fleet’s principal surface force. MCSOFEX is an exercise that promotes regional security cooperation, maintains and strengthens alliances, and enhances interoperability with the ROK Navy. (U.S. Navy photo by Mass Communication Specialist 2nd Class Oscar Diaz).
The Republic of Korea (ROK) Chungmugong Yi Sun-sin-class guided-missile destroyer ROKS Wang Geon (DDG 978) travels aft of Arleigh Burke-class guided-missile destroyer USS Dewey (DDG 105) during the Maritime Counter Special Operations Exercise (MCSOFEX) with the ROK Navy Nov. 18, 2025.
251118-N-JJ672-1232 AT SEA (Nov. 18, 2025) – The Republic of Korea (ROK) Chungmugong Yi Sun-sin-class guided-missile destroyer ROKS Wang Geon (DDG 978) travels aft of Arleigh Burke-class guided-missile destroyer USS Dewey (DDG 105) during the Maritime Counter Special Operations Exercise (MCSOFEX) with the ROK Navy Nov. 18, 2025. Dewey is forward-deployed and assigned to Destroyer Squadron (DESRON) 15, the Navy’s largest DESRON and the U.S. 7th Fleet’s principal surface force. MCSOFEX is an exercise that promotes regional security cooperation, maintains and strengthens alliances, and enhances interoperability with the ROK Navy. (U.S. Navy photo by Mass Communication Specialist 2nd Class Oscar Diaz).
The Republic of Korea (ROK) Navy Chungmugong Yi Sun-sin-class destroyer ROKS Wang Geon (DDG 978), right, and Daegu-class frigate ROKS Daejeon (FFG 823), left, sail in formation alongside the Arleigh Burke-class guided-missile destroyer USS Dewey (DDG 105) during the Maritime Counter Special Operations Exercise (MCSOFEX) with the ROK Navy Nov. 18, 2025.
251118-N-JJ672-1291 AT SEA (Nov. 18, 2025) – The Republic of Korea (ROK) Navy Chungmugong Yi Sun-sin-class destroyer ROKS Wang Geon (DDG 978), right, and Daegu-class frigate ROKS Daejeon (FFG 823), left, sail in formation alongside the Arleigh Burke-class guided-missile destroyer USS Dewey (DDG 105) during the Maritime Counter Special Operations Exercise (MCSOFEX) with the ROK Navy Nov. 18, 2025. Dewey is forward-deployed and assigned to Destroyer Squadron (DESRON) 15, the Navy’s largest DESRON and the U.S. 7th Fleet’s principal surface force. MCSOFEX is an exercise that promotes regional security cooperation, maintains and strengthens alliances, and enhances interoperability with the ROK Navy. (U.S. Navy photo by Mass Communication Specialist 2nd Class Oscar Diaz).
The Republic of Korea (ROK) Sejong the Great-class guided-missile destroyer ROKS Seoae Ryu Seong-ryong (DDG 993) travels alongside Arleigh Burke-class guided-missile destroyer USS Dewey (DDG 105) during the Maritime Counter Special Operations Exercise (MCSOFEX) with the ROK Navy Nov. 18, 2025.
251118-N-JJ672-1281 AT SEA (Nov. 18, 2025) – The Republic of Korea (ROK) Sejong the Great-class guided-missile destroyer ROKS Seoae Ryu Seong-ryong (DDG 993) travels alongside Arleigh Burke-class guided-missile destroyer USS Dewey (DDG 105) during the Maritime Counter Special Operations Exercise (MCSOFEX) with the ROK Navy Nov. 18, 2025. Dewey is forward-deployed and assigned to Destroyer Squadron (DESRON) 15, the Navy’s largest DESRON and the U.S. 7th Fleet’s principal surface force. MCSOFEX is an exercise that promotes regional security cooperation, maintains and strengthens alliances, and enhances interoperability with the ROK Navy. (U.S. Navy photo by Mass Communication Specialist 2nd Class Oscar Diaz).

 
During MCSOFEX, participating units conducted a wide range of training activities at sea and ashore, including in-port academics, a pre-sail conference, liaison officer exchanges, anti-submarine warfare training, anti-air warfare training, joint maritime interdiction operations, and dynamic formation sailing. Bilateral training activities like MCSOFEX provide valuable opportunities for the two navies to improve combined readiness, strengthen cooperation, and develop maritime capabilities.
  
Dewey is assigned to DESRON 15, the Navy’s largest DESRON and the U.S. 7th Fleet’s principal surface force.   
 
U.S. 7th Fleet is the U.S. Navy's largest forward-deployed numbered fleet and routinely interacts and operates with allies and partners in preserving a free and open Indo-Pacific region.

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