The increase of ship traffic flow, densities, ship size, and the uncertainty from technological advancement raise issues in traffic safety and efficiency. In order to tackle the issue, currently, a simulation model is widely used by various users as the port authority and bridge team and for research and development team. Since the issues are varied for each modeling user, the modeling purposes are also different among the users. Therefore, this research aimed to find the insight into modeling paradigms in simulating the vessel dynamic kinetic information (position, speed, course, and heading) and the encountering (overtaking, head-on, and crossing). A requirement of both aspects for each modeling purposes is set based on the simulation output needed. The insight is gained through comparison of models of the dynamic kinetic information and the encounters in six paradigms. The paradigms are Cellular Automata (CA), Generic Rule-Based (GRB), Specific Rule-Based Model (SRB), Artificial Potential Field (APF), Optimal Control (OC), and System Dynamics (SD). This research also provides an extension of the model by Shu et al. (2015a, 2015b, 2018) with OC paradigm to serve as the safety assessment for the port authority.