Raymarine AIS 4000: The Raymarine AIS 4000 is an Automatic Identification System (AIS) transponder used for tracking vessels and enhancing maritime safety. It transmits the vessel’s information, including its position, speed, and course, to nearby ships and shore stations. The AIS 4000 is essential for collision avoidance and navigation in busy maritime environments. Regular checks and servicing of the AIS unit ensure it remains functional and provides accurate data for safe operations.