[Former Proud Canadian]

So, you don’t think USN or ROK ASW is up to the task of neutralizing Nork subs?

[Chode]

according to the Korean Herald

Several North Korean submarines have disappeared after departing from bases on the eastern coast. According to reports, three or four North Korean submarines recently departed from bases on the east coast and have since remained outside South Korean surveillance.

The submarines are thought to be 370-ton shark-class vessels. The North Korean submarine used in the attack on the Cheonan in March 2010 was a 130-ton salmon-class vessel. North Korea has between 70 and 80 submarines ranging from 1,500-ton vessels to 130-ton vessels. Of the total, 80 percent are said to be based in the East Sea, where the waters are deeper than the West Sea, providing better conditions for submarine operations.

[AmericanInTokyo]

I dunno. You’d probably have to ask the families of the deceased crew members of the Cheonan (ROK Navy).