This paper presents a preliminary design of autonomous underwater vehicle platform entitled as KAUV-1. It is shaped like a torpedo with light weight and small size and is used for marine exploration and monitoring. The KAUV-1 has a unique ducted propeller located at aft end with yawing actuation acting as a rudder. For depth control, the KAUV-1 uses a mass shifter mechanism to change its center of gravity, and consequently, can control pitch angle and then depth of the vehicle. The paper also presents about equations of motion and a particular PD depth control strategy for the KAUV-1. The proposed system is validated by simulating performance of the vehicle with a developed depth controller.