US and partner nations hold SINKEX during RIMPAC 26

Ships and aircraft taking part in Rim of the Pacific (RIMPAC) 2026 carried out two planned live-fire sinking exercises, 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 hulks were sunk in waters about 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.”

Units from Australia, Canada, Italy, Japan, New Zealand, Spain and the U.S. Navy, Air Force and Army participated, building proficiency in tactics, targeting and live-fire engagements against a surface ship at sea. The training is designed to sharpen partner forces’ ability to coordinate, plan and execute complex maritime operations, including precision targeting and strike missions.

“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 SINKEX was conducted only after the area was surveyed to ensure no people, vessels, aircraft or marine species were present. The events were planned under the National Environmental Policy Act and executed consistent with permits and authorizations under the Marine Mammal Protection Act, Endangered Species Act, and Marine Protection, Research, and Sanctuaries Act.

USS Mobile Bay, a Ticonderoga-class guided missile cruiser, entered service on Feb. 21, 1987, at the Alabama State Docks in Mobile, Alabama. Initially homeported in Mayport, Florida, until 1990, the ship later joined U.S. 7th Fleet in Yokosuka, Japan. Over more than three decades, Mobile Bay supported Operations Desert Shield, Desert Storm and Iraqi Freedom, and provided humanitarian aid after the 1991 Mount Pinatubo eruption in the Philippines. It was decommissioned in August 2023 after over 36 years of service.

USS Peleliu, a Tarawa-class amphibious assault ship named for the World War II Battle of Peleliu, was commissioned on May 3, 1980, and homeported in San Diego. Displacing nearly 40,000 tons, the ship operated a range of aircraft from its large flight deck while conducting combat operations and humanitarian missions across multiple regions. Across 17 deployments, Peleliu supported Operations Desert Storm and Iraqi Freedom and delivered relief following the 1991 Mount Pinatubo eruption and the 2010 Pakistan floods. It was decommissioned in March 2015 after 35 years of service.

This year’s RIMPAC brings together 30 nations, 30 surface ships, five submarines, 15 national land forces, more than 190 aircraft and 30,000 personnel in and around the Hawaiian Islands from June 24 to July 31. Billed as the world’s largest combined-joint maritime exercise, the series—now in its 30th iteration since beginning in 1971—aims to strengthen cooperative relationships that help ensure the safety of sea lanes and security across the world’s oceans.