The Philippine Navy (PN) on Monday canceled the Maritime Strike (MARSTRIKE) live-fire and ship-sinking exercise after its designated target vessel, the decommissioned BRP Miguel Malvar (PS-19), sank prematurely off the west coast of the Philippines.

In a media briefing at Navy headquarters in Manila, PN spokesperson Capt. John Percie Alcos said the ship sank on its own at around 7:20 a.m., roughly 30 nautical miles west of San Antonio, Zambales — at the designated location for the maritime drill.

"No personnel were injured. Prior to towing the target vessel to the operational area, the BRP Miguel Malvar underwent environmental cleaning and preparation for the MARSTRIKE," Alcos said.

"As is common, the vessel was selected because it exceeded its service life and was no longer suitable for normal operations," he added.

Alcos said the ship had passed stringent evaluations and met all criteria for being used as a mock enemy target for the drill.

"However, due to rough sea conditions that we are currently experiencing in the exercise box, and with its long service life, as it's expected, she took on a significant amount of water, and eventually sank," he explained.

The MARSTRIKE exercise is part of the 40th iteration of the Balikatan Exercises, held annually between the armed forces of the Philippines and the United States. The drills aim to integrate ground, air, and maritime sensors and shooters into a joint fires network, enhancing combined warfighting capability and command and control.

Despite the loss of the target ship, Alcos said other live-fire components of MARSTRIKE would still proceed in a simulated format.

"Elements of the scheduled MARSTRIKE live-fire event will occur and the combined force will still achieve its training objectives," he said, while withholding specific details due to operational security.

Alcos also confirmed that existing Notices to Mariners and Notices to Airmen around the MARSTRIKE area remain in effect.

The BRP Miguel Malvar, formerly the USS Brattleboro, was originally deployed by the U.S. Navy in the 1940s and later served with the Vietnam Navy before being transferred to the Philippine Navy in 1977. As one of the PN's oldest corvette ships, it participated in various missions including World War II, the Vietnam War, and operations in the West Philippine Sea.