Maritime security has become major concerns of all coastal states, and the fundamental requirement is "maritime domain awareness" via identification, tracking and monitoring of vessels within their waters. We first identify candidate technologies and systems for different types of vessels. These systems have been designed and provided with regulatory framework for other reasons such as sustainable fishery, search and rescue, environmental protection, navigational safety, etc. We then present the results of a feasibility study on the application and integration of the technologies and facilities of these systems for maritime security. The technologies such as automatic identification systems (AIS), Inmarsat-C, and digital selective calling (DSC) and GSM are investigated with regard to the propagation/coverage, cost, reliability, etc. based on sea trials and field tests of prototype subsystems. Finally, we propose an integrated vessel identification and monitoring system and present a prototype system to demonstrate the display and fusion of targets from various sources including radar surveillance.