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U.S., ROK navies strengthen combined undersea warfare during Silent Shark 2025

11 December 2025

From Commander, Submarine Squadron 15 Public Affairs

The U.S. Navy and Republic of Korea (ROK) Navy successfully completed the biennial theater anti-submarine warfare (TASW) exercise Silent Shark 2025 in Guam, Dec. 11. Organized by Commander, Submarine Group 7 (CSG-7), Silent Shark is a long-standing bilateral exercise designed to strengthen interoperability and advance combined TASW capabilities between the U.S. and ROK navies. This year marks the 10th iteration, following the previous exercise in 2023.

Crew members assigned to the Republic of Korea (ROK) Submarine Ahn Mu (SS 085) participate in a submarine training evolution during a visit to Naval Submarine Training Center Pacific (NSTCP) Detachment Guam, Dec. 1, 2025.
NAVAL BASE GUAM (Dec. 1, 2025) – Crew members assigned to the Republic of Korea (ROK) Submarine Ahn Mu (SS 085) participate in a submarine training evolution during a visit to Naval Submarine Training Center Pacific (NSTCP) Detachment Guam, Dec. 1, 2025. Ahn Mu is visiting Guam as part of Exercise Silent Shark 2025. Organized by Commander, Submarine Group 7 (CSG-7), Silent Shark is a long-standing bilateral exercise designed to strengthen interoperability and theater anti-submarine warfare between the U.S. and ROK. CSG-7 directs forward-deployed, combat-ready undersea forces across the Western Pacific, Indian Ocean, and Arabian Sea under U.S. 7th Fleet. Portions of the image are changed due to security concerns. (U.S. Navy photo by Mass Communication Specialist 1st Class Karri Langerman)
Crew members assigned to the Republic of Korea (ROK) Submarine Ahn Mu (SS 085) participate in a submarine training evolution during a visit to Naval Submarine Training Center Pacific (NSTCP) Detachment Guam, Dec. 1, 2025.
251201-N-SV075-1001
NAVAL BASE GUAM (Dec. 1, 2025) – Crew members assigned to the Republic of Korea (ROK) Submarine Ahn Mu (SS 085) participate in a submarine training evolution during a visit to Naval Submarine Training Center Pacific (NSTCP) Detachment Guam, Dec. 1, 2025. Ahn Mu is visiting Guam as part of Exercise Silent Shark 2025. Organized by Commander, Submarine Group 7 (CSG-7), Silent Shark is a long-standing bilateral exercise designed to strengthen interoperability and theater anti-submarine warfare between the U.S. and ROK. CSG-7 directs forward-deployed, combat-ready undersea forces across the Western Pacific, Indian Ocean, and Arabian Sea under U.S. 7th Fleet. Portions of the image are changed due to security concerns. (U.S. Navy photo by Mass Communication Specialist 1st Class Karri Langerman)
Photo By: Mass Communication Specialist 1st Class Karri Langerman
VIRIN: 251201-N-SV075-1001

 
Silent Shark 2025 brought together a U.S. Navy fast-attack submarine, the ROK Navy’s Dosan Ahn Changho–class submarine ROKS Ahn Mu (SS-085), and maritime patrol and reconnaissance aircraft from both nations. Conducted in the vicinity of Guam, the exercise featured at-sea and in-port events focused on submarine tracking and engagement tactics, improving theater-level undersea warfare capabilities vital to stability across the Western Pacific.
 
While ashore, Ahn Mu’s crew worked alongside U.S. Sailors at Naval Submarine Training Center Pacific (NSTCP) Detachment Guam, participating in classroom instruction, integrated navigation training, and hands-on operations using the Integrated Submarine Piloting and Navigation (ISPAN) trainer. ROK Navy leadership also met with regional commanders, including Capt. Neil Steinhagen, commander, Submarine Squadron 15, and Ahn Mu crew members toured the Los Angeles–class fast-attack submarine USS Springfield (SSN 761), further strengthening professional ties and mutual understanding between the two forces.
 
“Being forward deployed gives us unique, hands-on opportunities to work directly with our allies,” said Cmdr. Greg Storer, commanding officer of Springfield. “What we learn together—and the partnerships we continue to build—are vital to how we operate forward in the region. Exercises like Silent Shark play a critical role in strengthening operational readiness, enhancing interoperability, and reinforcing our combined efforts to maintain stability and security across the Indo-Pacific.”

Capt. Geonyoung Ahn, commanding officer of the Republic of Korea (ROK) submarine Ahn Mu (SS 085), center-left, speaks with Cmdr. AJ Franz, commanding officer of Los Angeles-class fast-attack submarine USS Jefferson City (SSN 759), left, and Cmdr. Greg Storer, commanding officer of Los Angeles-class fast-attack submarine USS Springfield (SSN 761), center, during a visit aboard Springfield for Exercise Silent Shark 2025.
NAVAL BASE GUAM (Dec. 2, 2025) – Capt. Geonyoung Ahn, commanding officer of the Republic of Korea (ROK) submarine Ahn Mu (SS 085), center-left, speaks with Cmdr. AJ Franz, commanding officer of Los Angeles-class fast-attack submarine USS Jefferson City (SSN 759), left, and Cmdr. Greg Storer, commanding officer of Los Angeles-class fast-attack submarine USS Springfield (SSN 761), center, during a visit aboard Springfield for Exercise Silent Shark 2025. Organized by Commander, Submarine Group 7 (CSG-7), Silent Shark is a long-standing bilateral exercise designed to strengthen interoperability and theater anti-submarine warfare between the U.S. and ROK. CSG-7 directs forward-deployed, combat-ready undersea forces across the Western Pacific, Indian Ocean, and Arabian Sea under U.S. 7th Fleet. (U.S. Navy photo by Mass Communication Specialist 1st Class Bryan Mai)
Crew members assigned to the Republic of Korea (ROK) Submarine Ahn Mu (SS 085) participate in a submarine training evolution during a visit to Naval Submarine Training Center Pacific (NSTCP) Detachment Guam, Dec. 1, 2025.
NAVAL BASE GUAM (Dec. 1, 2025) – Crew members assigned to the Republic of Korea (ROK) Submarine Ahn Mu (SS 085) participate in a submarine training evolution during a visit to Naval Submarine Training Center Pacific (NSTCP) Detachment Guam, Dec. 1, 2025. Ahn Mu is visiting Guam as part of Exercise Silent Shark 2025. Organized by Commander, Submarine Group 7 (CSG-7), Silent Shark is a long-standing bilateral exercise designed to strengthen interoperability and theater anti-submarine warfare between the U.S. and ROK. CSG-7 directs forward-deployed, combat-ready undersea forces across the Western Pacific, Indian Ocean, and Arabian Sea under U.S. 7th Fleet. Portions of the image are changed due to security concerns. (U.S. Navy photo by Mass Communication Specialist 1st Class Karri Langerman)

 
Silent Shark 2025 underscores the United States’ commitment to the Indo-Pacific and complements the broad range of exercises, operations, and military cooperation conducted between U.S. submarine forces and the ROK Navy.
 
Commander, Submarine Group 7 (CSG-7) directs forward-deployed, combat-ready undersea forces across the Western Pacific, Indian Ocean, and Arabian Sea under U.S. 7th Fleet.

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