The 1998 Yosu submersible incident was a naval skirmish that occurred off of the southern coast of South Korea between 17 and 18 December 1998.

The vessel that was salvaged in the Yosu incident was reportedly equipped with GPS and its surface was coated with a special radar absorbent paint.

[3] On 17 December 1998, at 23:15, soldiers at a coastal surveillance post reported sighting a low-profile vessel maneuvering 2 km from the coast.

Fifteen minutes later, two Republic of Korea Navy patrol boats were dispatched to search the area, but did not discover the vessel.

[4] At approximately 01:40 the following day, a semi-submersible was detected heading towards international waters and two patrol boats gave chase.

This incident helped fuel increasing tensions between the two governments and an even larger naval skirmish was fought the next year.

They also said that they issued an order called "Jindogae nN.1" throughout the coastal areas of South Korea and have been put on the red alert.