The Navy is scheduled to hold a formal event later this week to mark the 15th anniversary of the battle.

On June 29 during the 2002 Korea-Japan FIFA World Cup, two North Korean boats crossed the NLL, the de-facto sea border between the two Koreas.

They suddenly opened fire on the Chamsuri-357 South Korean patrol ship, provoking it to return fire. One of the North Korean ships was heavily damaged and more than 30 North Koreans are believed to have been killed or wounded. Six South Korean sailors were killed and 19 others injured.

The South's Navy later commissioned six high-speed patrol ships, equipped with guided missiles and named each after them, for patrol mission near the NLL.

"The fathers of the six brave soldiers will be appointed as honorary captains of the ships in the 15th anniversary ceremony to be held at the Second Fleet Command in Pyeongtaek on Thursday," the Navy said.

Yoon Doo-ho, the father of late Lt. Cdr. Yoon Young-ha, said, "The bereaved families want just one thing. It's that the people forever remember all soldiers who made sacrifices for our country including the six sailors."

The 2002 skirmish served as a harsh reminder of the reality that the two Koreas are still technically at war as they have yet to sign a peace treaty to formally end the 1950-53 Korean War.

A similar inter-Korean naval battle took place on June 15, 1999, off the island of Yeonpyeong close to the NLL. Seven South Korean sailors were wounded. The number of the North's casualties remains unconfirmed. (Yonhap)