Chinese Navy Submarine Support Ship Sails Through Tsushima Strait: First-Ever Sighting Raises Questions

In a strategic development closely watched by regional powers, a Chinese People’s Liberation Army Navy (PLAN) Dakai-class submarine rescue vessel has, for the first time, transited through the Tsushima Strait—an important waterway connecting the East China Sea with the Sea of Japan. The move has sparked attention due to the vessel’s capabilities and the broader naval movements observed in the region.

Key Sighting: Dakai-Class Submarine Rescue Vessel

According to Japan’s Maritime Self-Defense Force (JMSDF), the PLAN ship with hull number 841—classified under the newly inducted Dakai-class submarine rescue category—was spotted around 205 miles west of Japan’s Goto Islands.

Key Details:

Date of Sighting: Reported by Japanese officials this week.

Location: Tsushima Strait → Sea of Japan

Vessel Type: Dakai-class – newest submarine rescue vessel (entered service in 2024)

Support: Shadowed by JMSDF aircraft from Kanoya Air Base and Fleet Air Wing 4 (Atsugi)

This is the first confirmed presence of a Chinese submarine support ship in this critical maritime corrido

Additional PLAN Movements Near Japan

On Thursday around 4:00 a.m., multiple PLAN surface vessels were observed operating in the same region:

Sighted Vessels:

• CNS Urmuqi (Destroyer)
• CNS Shoxinf (Destroyer)
• CNS Qiandaohu (Fleet Oiler)

These ships were seen 55 miles west of the Goto Islands, sailing northeast through the Tsushima Strait.

Japanese Response:

• Monitored by JS Shirataka (Fast Attack Craft)
• Supported by P-1 Maritime Patrol Aircraft (Fleet Air Wing 1)

Strategic Context: Joint Exercises & Russian Drills
The presence of multiple PLAN warships in the Sea of Japan coincides with the Russian Navy’s “July Storm” exercises, which began on Wednesday. These drills include:

Units from Northern, Pacific, Baltic Fleets, and the Caspian Flotilla

Potential coordination or observation by Chinese naval forces remains unconfirmed

In 2024, PLAN ships also took part in “Ocean 2024”, a joint exercise in the Pacific alongside Russia.

Possible Missions Behind the Deployment

While the exact objective of the Dakai-class 841 vessel remains unclear, experts speculate the following possibilities:

• Submarine support deployment in preparation for future joint drills
• Training mission before full operational integration
• Routine long-range navigation exercise

Earlier this week, another PLAN ship—Tianlangxing (794), a Dongdiao-class surveillance vessel—was spotted 80 miles northeast of Miyako Island, entering the East China Sea, suggesting broader PLAN activity in the region.