On Monday (21/10/2024) Indonesian Coast Guard and Navy expelled CCG 5402 (left center) from North Natuna Sea after it was reported to have disrupted seismic survey activities. In the photo, the Indonesian CG vessel, KN Tj data (lower right) is supported by the Indonesian Navy vessel KRI Sutedi Senoputra,  (upper right) Source: X

MSN reports,

“Indonesia on Monday expelled a Chinese coast guard ship from its maritime zone after it allegedly interfered with a seismic survey operation.”

“An Indonesian coast guard cutter approached the Chinese ship, coming within around 8 miles of it and issuing a radio warning. However, the Chinese vessel insisted it was operating within Chinese waters.”

The Indonesian Navy sent reinforcements to support the cutter in the form of a patrol aircraft and a corvette.

“The Indonesian vessels shadowed the Chinese counterpart until it was ultimately expelled from Indonesia’s EEZ, per the statement.”

How long that took is not clear.

The same China Coast Guard ship (bearing an earlier hull number) and a Philippine supply boat engage in a standoff as the Philippine boat attempts to reach the Second Thomas Shoal, a South China Sea reef inside the Philippine EEZ, on March 29, 2014, Jay Directo—AFP

Correlation of Forces:

Correlation of forces is a term the Soviets used, and the Chinese would understand. It means if there were conflict what would be the likely outcome, and in any tense situation, the thought has to be at least in the back of the mind of the players, and will influence decision makers. 

China CGC 5402 is reportedly a Zhaolai class, formerly hull number 3401. The Zhaolai-class China Coast Guard cutters are reported to have a displacement of 4,896 tons and are 99 meters in length. It is a relatively big cutter, but closer to an Offshore Support Vessel than a warship. They go back to at least 2014, and were built before the China Coast Guard began building cutters armed with medium caliber guns. It is not clear if China CGC 5402 is now armed with heavy weapons. In the photo above, a foundation for what would probably be a 76mm gun is visible, but I have seen no photos of this class so armed.

The Indonesian cutter, KN Tanjung Datu, is the largest cutter in the Indonesian CG. It is reportedly 2400 tons, but I suspect the full load displacement is greater considering it is 110 meters (360′) in length with a beam of 15.5 m (51′), making it almost as large as the USCG’s new 4,500 ton Offshore Patrol Cutters. The USCG has exercised with her (photo below). She is armed with a 30mm Mk44 chain gun in a Aselsan SMASH remote weapon station, but the Indonesians did not assume that would be enough. They called in reinforcements in case things went South.

Indonesian Maritime Security Agency vessel KN Tanjung Datu, left, sails alongside U.S. Coast Guard Cutter Stratton during joint exercises in the Singapore Strait in August 2019. IMAGE CREDIT: PO1 LEVI READ/USCG

The smallest vessel in the photo at the head of the post (KRI Sutedi Senoputra) was also, by far the most heavily armed. It is only 935 tons, full load, lighter than a WMEC210, and 43 years old, but it is faster than either of the cutters at 24 knots and armed with a twin 57mm, a twin 30mm, and two 20mm. It also has RBU-6000 ASW rocket launchers which may have some anti-surface capability. (see photo below)

The Indonesian Corvette, KRI Sutedi Senoputra, is a former East German Parchim class corvette like this one.

The incident happened within 200 nautical miles of Indonesian territory so attack aircraft would not be too far away.

The Indonesians have been acting aggressively against Chinese fishing vessels in their EEZ. They don’t seem to be unwilling to insist on their rights.

The Chinese probably don’t want to risk an armed conflict before they are ready to attack Taiwan with all the logistical preparation that would require. They seem to have been losing influence in Indonesia, and don’t want further alienate Indonesia and to push them closer to the US.