Korean Navy's P-8 demonstrates submarine-hunting capability at RIMPAC

A Korea Navy P-8A maritime patrol aircraft prepares for a joint anti-submarine warfare exercise during the 2026 Rim of the Pacific Exercise at Joint Base Pearl Harbor-Hickam in Honolulu, Monday. Korea Times photo by Bahk Eun-ji

HONOLULU — At 9:54 a.m. Monday, a Republic of Korea Navy P-8A Poseidon roared down the runway at Joint Base Pearl Harbor-Hickam and climbed over the Pacific, heading toward its assigned patrol area.

Minutes later, a U.S. Navy P-8A lifted off from Kalaeloa Airport, marking the start of another joint anti-submarine warfare mission during this year’s Rim of the Pacific Exercise (RIMPAC).

For the Korean Navy, the flight carried added significance.

It marked the Korean Navy’s first RIMPAC deployment of the newly introduced P-8A maritime patrol aircraft and the first time reporters were allowed to observe one of its operational missions while onboard.

The exercise centered on tracking a submarine target simulator designed to replicate the movements of a real submarine. Before the patrol aircraft arrived, the U.S. Navy deployed separate simulators into the Korean and American operating sectors.

Once in the water, the devices quietly followed preprogrammed routes while attempting to avoid detection.

The mission for both aircraft was straightforward in concept but notoriously difficult in practice: locate the submerged target, track its movements, block its escape route and complete a simulated attack.

Immediately after takeoff, the two aircraft established a tactical data link, allowing both crews to share their locations and a common operational picture in real time before entering the search phase.

A Korea Navy sailor loads sonobuoys onto a P-8A maritime patrol aircraft at Joint Base Pearl Harbor-Hickam in Honolulu, Monday, before the aircraft’s departure for a joint anti-submarine warfare exercise during the 2026 Rim of the Pacific Exercise. Korea Times photo by Bahk Eun-ji

At 10:07 a.m., shortly after reaching the designated area, the Korean aircraft’s tactical coordinator gave the order.

“Sonobuoy drop. Now, now, now!”

Two sonobuoys splashed into the ocean below.

Rather than searching blindly across the vast Pacific, anti-submarine crews narrow the search area by placing sonobuoys in carefully calculated patterns based on the submarine’s estimated position, the surrounding sea conditions and seasonal ocean characteristics.

Coastal waters with heavy commercial shipping, for example, often require denser buoy placement because underwater background noise makes acoustic detection more difficult.

The Korean crew eventually released four sonobuoys, forming a rectangular search pattern across the water. The search effort was then reinforced by nine additional sonobuoys deployed by the U.S. aircraft, expanding the joint acoustic search field.

Just one minute after both sides completed their buoy deployment, thin vertical lines suddenly appeared across the acoustic displays inside the Korean aircraft.

The signals indicated that the simulated submarine had entered the overlapping detection range created by the two countries’ sonobuoy fields.

A mission control console is seen inside a Korea Navy P-8A maritime patrol aircraft during a joint anti-submarine warfare exercise as part of the 2026 Rim of the Pacific Exercise near Honolulu, Monday. Korea Times photo by Bahk Eun-ji

As underwater acoustic signals streamed back from the sonobuoys, the aircraft’s acoustic operator quickly analyzed the data, calculating the target’s estimated position, heading and speed within moments.

The sonobuoys were only one part of the aircraft’s surveillance capability.

The P-8A also carries a powerful X-band maritime radar capable of detecting surface targets hundreds of kilometers away, as well as high-resolution electro-optical and infrared sensors that can identify targets from dozens of kilometers away. Electronic support measures further allow the aircraft to detect and classify electromagnetic emissions across a broad area.

These systems are particularly valuable against diesel-electric submarines.

Even while remaining submerged, such submarines must occasionally raise a mast above the surface to check their surroundings before resurfacing safely. Although the exposure lasts only briefly, it can provide enough of a radar return for the P-8A to detect and begin tracking it.

Compared with the aging P-3 maritime patrol aircraft it is replacing, the P-8A offers roughly twice the acoustic detection capability, carries about 120 sonobuoys — roughly 1.5 times more than the P-3 — and features significantly improved sensors and mission systems. As of this year, the Korean Navy operates six P-8As.

“People often compare finding a submarine in the open ocean to looking for a needle in a haystack,” said Cmdr. Lee Tae-hee, commanding officer of the Korean Navy’s P-8 Detachment.

A U.S. Navy P-8A maritime patrol aircraft appears on a tactical situation display inside a Korea Navy P-8A during a joint anti-submarine warfare exercise as part of the 2026 Rim of the Pacific Exercise near Honolulu, Monday. Korea Times photo by Bahk Eun-ji

“But the P-8 is among the world’s most capable maritime patrol aircraft. Building on one of the world’s most advanced maritime patrol platforms and increasingly sophisticated tactics, we will continue strengthening our readiness to respond immediately to any threat at sea.”

Once the target’s location had been confirmed, the Korean crew dropped an underwater sound signal generator to order the submarine to surface. When no response came, the aircraft proceeded to the next phase of the exercise.

Descending to about 300 meters, the P-8 simulated the release of an MK-54 lightweight torpedo through its weapons bay.

The attack marked the end of the mission at around 10:55 a.m. Less than 30 minutes had passed from the moment the search began to the completion of the simulated strike.

Monday’s sortie marked the final Korea-U.S. anti-submarine warfare drill of this year’s RIMPAC. During the remainder of the exercise, the two navies will join partner nations in a series of multinational anti-surface warfare drills, with the Korean Navy deploying its P-8A Poseidon and AW-159 Wildcat maritime helicopters as key aviation assets in the combined operations.