Maritime surveillance is progressively becoming a critical component for managing marine areas such as exclusive economic zone (EEZ) in coastal states around the world. The Over-The-Horizon (OTH) high-frequency (HF) radars are capable to cover a wide area for ship detection. With established island-wide HF radar observation network in Taiwan, it is worthwhile to develop vessel detection and tracking tools with this network. Such implement would become the new option to provide various advantages such as low cost, active detection, and near the real-time performance. The data from Ciho SeaSonde radar station were used in the current study; these data were first processed to provide the radial velocity components of ship motions which are then compared against those derived from Automatic Identification Systems (AIS) data. Present study indicated the potential capability for vessel detection with SeaSonde HF radar.