The Republic of Korea Navy has concluded the recent damage to a Daegu-class frigate was due to "mishandling" by its officers and crew which possibly led it to run aground as it was approaching Jinhae Port in South Gyeongsang Province in January.
The operation of the frigate was put on hold as the Navy analyzed the cause of the accident and assessed damage to the ship's propeller.
"It seems the Daegu-class frigate crossed a low-water area, possibly lower than its limit of around five to six meters, in the process of docking while carrying a full load of munitions," a Navy official said during a press briefing Thursday.
"The propeller of the frigate seemed to have been damaged by rocks."
The official said the captain of the frigate, who has since been relieved from his post, sent divers to check the propeller and the underside of the ship the following day.
But as it seemed undamaged to the naked eye, the captain continued to operate the ship.
The Navy said it has not found any other mechanical problems with the ship and it will resume full operation in July at the earliest once the damaged propeller has been replaced and sea trials conducted.
It said it will seek to strengthen security measures on its ships.