No, it cannot identify every vessel at sea due to equipment gaps and data limitations.
The Automatic Identification System is a cooperative VHF data system through which equipped ships and shore facilities automatically exchange identity, position, course, speed, navigational status and other safety-related information. This design relies on voluntary participation from fitted units rather than universal coverage of the maritime domain.
Consequently, gaps in visibility are common because not all ships carry AIS. Furthermore, fitted units may be switched off in limited safety or security circumstances, leaving those specific vessels unreported to nearby receivers. Even when signals are present, received data may be incomplete, unavailable or wrong due to technical limitations or environmental factors.
AIS does not prevent collisions by itself and does not replace visual lookout, radar plotting, use of all available means or compliance with the COLREG. Operators must treat AIS as one tool among many, recognizing that it cannot identify every vessel at sea and should never be relied upon as a sole source of situational awareness.
