South Korea, together with the US, will stage joint anti-submarine exercises twice a year from 2011 in the East and West Seas to boost its anti-submarine drills, the South Korean chief of naval operations Admiral Kim Sung-chan has said.

The navy will equip 12 Korean ships with joint command and control systems to allow Korean forces to access worldwide military intelligence from US naval vessels.

The flight limit line for P-3C maritime patrol aircraft has been extended by 27.8km further towards the northern limit line to increase the efficiency of anti-submarine operations in the West Sea.

About 30 high-speed boats of the Second Fleet Command have been fitted with fish detectors, and the sonar on 12 destroyers, frigates and patrol ships has been replaced.

The navy will also procure 12 rigid-hulled inflatable boats for coastal underwater searches by 2012 and build anti-sub training ranges for the First and Second Fleet Commands by 2014.

The number of 214 Class 1,800t submarines will be increased from three to nine by 2018, nine 3,000t next-generation submarines will be procured after 2020, and 20 2,300t future frigates will replace superannuated frigates and corvettes.

A 14,500t landing ship, which can be remodelled as a light aircraft carrier within six months, will also be built by 2018, according to the Chosun Ilbo.