After losing a corvette to a North Korean submarine earlier this year, South Korea is, understandably, working hard to increase its ASW (Anti-Submarine Warfare) capabilities. Short term, it has equipped 30 fast patrol boats with commercial sonar (used for detecting fish, but also capable to detecting subs in shallow coastal waters) and installed improved military sonars on over a dozen larger warships. The navy is also buying a dozen fast rigid inflatable boats, equipped with sonar, for searching coastal waters for the smaller North Korean subs. P-3C anti-submarine aircraft are now allowed to operate closer to the Northern Limit Line (the unofficial maritime border between north and south Korea.)
Longer term, new ASW training areas are being built on each coast over the next two years. These areas will have electronic sensors to score how well ships perform in their hunt for submerged targets. Already underway are building programs to construct 20 new frigates and six more submarines. There are also plans to built a 15,000 ton ASW carrier (with six ASW helicopters). The navy is investigating obtaining more advanced American helicopter ASW gear. Finally, ASW training exercises will be held with American ships annually (once a year off each coast). New communications gear is being installed in South Korea warships, to make it easier for them to exchange ASW data with their American counterparts.