AIS Plotter Icons

Blue vessel icon

Your vessel

Vessel icon

Class A vessel1

Triangular vessel icon

Class B vessel2

Yellow square

Aid to Navigation (AtoN) device

Red circle

Man Overboard (MOB) device

The vessel class depends on the type of AIS transmitter on the vessel. Class A transmitters tend to be on larger ocean-going vessels, and class B transmitters tend to be on smaller coastal vessels. A class A AIS transmitter reaches longer distances and reports more information than a class B transmitter.

1 Shown in orange or red when there is a risk of collision.
2 Shown in orange or red when there is a risk of collision.
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May 2026