Which symbol on the track indicates Encrypted AIS Tracks?

• A. Light blue donut
• B. Green circle
• C. Red square
• D. Yellow triangle

Answer: (A)

Understanding how encryption status is shown on the AIS track display helps you quickly judge whether you can read the data or not. The symbol used for encrypted AIS Tracks is a light blue donut that appears on the track. This distinct shape and color pair are designed to stand out from other track icons, so at a glance you can tell which data streams are secured and require special access or decryption keys.

In the AIS system, not all tracks carry the same access permissions. Encryption protects sensitive vessel information, and the light blue donut marker communicates that a particular track is encrypted, guiding operators to treat that data as restricted. The other symbols—green circle, red square, yellow triangle—are used for different, non-encrypted statuses or classifications, so they don’t indicate encryption.