When associated with a track, what does a light blue donut represent?

• A. Encrypted AIS Tracks
• B. Valid radar target
• C. Unknown track
• D. Weather feature

Answer: (A)

The light blue donut around the track signals an AIS-derived target that is encrypted. AIS provides vessel identity and dynamic data, but when encryption is applied, that sensitive information is protected; you can still see the track’s movement, but you can’t read or rely on the vessel’s identifying data from the AIS feed. This visual cue lets you distinguish encrypted AIS tracks from regular AIS tracks or radar-only targets, so you know to approach with the appropriate caution and not expect readable AIS details. If it were a plain radar target, it would use standard radar symbols; an unknown track would look different as well, and weather features have their own distinctive representation.