The Dolgorae class is a type of midget submarine designed and acquired for the ROK Navy. There are currently two operational units in service. These midget submarines were the first South Korean submarines of any type. They were acquired primarily to obtain initial experience with the basics of operating a submarine force. The secondary mission to train surface ASW ships in the detection of North Korean midget submarines. With the Type 209 project completed there is less need for these submarines. In November 2011, South Korea unveiled plans for a new mini-sub designated KSS-500A.