December 2, 2011: South Korea is replacing two elderly 250 ton Italian mini-submarines (from the 1980s) with the locally designed KSS 500A. This is a 510 ton, 37 meter (115 foot) long, 4.5 meter (14 foot) diameter boat. It cruises at 12 kilometers an hour (for up to 21 days) and can hit a top speed of about 36 kilometers an hour. Maximum dive depth is 250 meters (775 feet). Meant for coastal operations, the 500A would be useful against North Korea or even China or Japan.

Each 500A can carry two heavy and four light torpedoes. There is also space for some mines and vertical launched missiles. The boat also has accommodations for 14 commandos and the capacity for them to use scuba gear to leave the sub while submerged.

The submarines crew consists of ten sailors, and all power is carried in lithium-ion batteries. South Korea plans to build five of these boats. Design work began three years ago, and construction is to begin next year.