This paper describes a microscopic nautical traffic simulation model based on multi-agent system. The ship traffic is produced from the behavior of autonomous agents that represent ships. Especially, we look at the behaviors for collision avoidance in different encountering situations with different local environmental conditions. The behavior of the ships is simulated with a dynamic ship maneuvering model, taking into account the movements in different local circumstances. And we utilize AIS data for input in simulation, model validation, and model verification. Moreover, we use the ODD (Overview, Design concepts, Details) protocol as a framework for the detailed description of the model.