The Royal Thai Navy is to purchase six second-hand submarines from Germany to protect national interests in the Andaman Sea and the Gulf of Thailand.

Thai Prime Minister Abhisit Vejjajiva has approved the 7.7bn-baht ($250m) purchase of the submarines for the first-ever military operation.

The missions will be commanded by the Thai Navy’s new submarine unit, and navy officers will, for the first time, undergo training in submarine technology and underwater missions with Thai-owned submarines.

The U-206 Class submarines are operated by diesel engines and electric motors and can travel to a depth of 30m.

The submarines have been in service with the German Navy for more than 30 years and can still be used for another ten years.

The purchase plan will be forwarded to the cabinet for formal approval in the near future, according to the Bangkok Post.