U.S. and partner nations stage SINKEX at RIMPAC 26

Ships and aircraft taking part in Rim of the Pacific (RIMPAC) 2026 conducted two planned live-fire sinking exercises in July, sending the decommissioned USS Mobile Bay (CG 53) to the seafloor on July 12 and the decommissioned USS Peleliu (LHA 5) on July 17. Both ships were sunk in waters roughly 15,000 feet deep, more than 50 nautical miles off the northern coast of Kauai.

“Watching our Sailors work side-by-side with partners from around the world, executing complex maritime events together, is the strongest reminder of why these relationships matter,” said U.S. Navy Vice Adm. Jeff Jablon, the RIMPAC 2026 Commander, Combined Task Force (CCTF). “SINKEXs are a prime example of the strength and readiness our partnerships create.”

Forces from Australia, Canada, Italy, Japan, New Zealand, Spain, and the U.S. Navy, Air Force, and Army participated, honing tactics, targeting, and coordinated live-fire against a surface vessel at sea. The events were designed to provide realistic, hands-on training to improve precision targeting, strike capabilities, and the planning and execution of complex maritime operations.

“The successful execution of multiple SINKEXs highlights the unbreakable bond and growing capability of our coalition,” said Republic of Korea Navy Rear Adm. Inho Kim, RIMPAC 2026 Combined Force Maritime Component Commander (CFMCC). “Together, we are demonstrating a shared commitment to regional stability by developing tactics and skills in maritime operations.”

Officials said each sinking exercise is conducted only after the area is surveyed for people, marine traffic, aircraft, and marine species. The operations are planned to comply with the National Environmental Policy Act and carried out under the Navy’s permits and authorizations pursuant to the Marine Mammal Protection Act, Endangered Species Act, and Marine Protection, Research, and Sanctuaries Act.

USS Mobile Bay, a Ticonderoga-class guided missile cruiser, was commissioned Feb. 21, 1987, initially homeported in Mayport, Florida, before joining U.S. 7th Fleet in Yokosuka, Japan. Over more than three decades, it supported Operations Desert Shield, Desert Storm, and Iraqi Freedom, and provided humanitarian assistance after the 1991 Mount Pinatubo eruption in the Philippines. The ship was decommissioned in August 2023.

Named for the World War II Battle of Peleliu, the Tarawa-class amphibious assault ship USS Peleliu was commissioned May 3, 1980, and homeported in San Diego. Displacing nearly 40,000 tons, it launched a variety of aircraft during combat operations and humanitarian missions across multiple theaters. Across 17 deployments, it supported Operations Desert Storm and Iraqi Freedom and delivered humanitarian aid following the 1991 Mount Pinatubo eruption and the 2010 Pakistan floods. Peleliu was decommissioned in March 2015.

This year’s RIMPAC, the 30th in a series that began in 1971, runs June 24 to July 31 in and around the Hawaiian Islands. Thirty nations are participating with 30 surface ships, five submarines, 15 national land forces, more than 190 aircraft, and 30,000 personnel, in an effort to strengthen cooperative relationships that underpin the safety of sea lanes and security across the world’s oceans.