Raymarine LIGHTHOUSE 4 Operation Instructions Manual page 188

Important:
The Collision Avoidance feature is a graphical aid only, provided to help
increase user awareness of the potential for collision. It is vital to have
a good understanding of the International Regulations for Preventing
Collisions at Sea (IRPCS / COLREGS), to ensure all actions taken are in
accordance with the IRPCS. Important concepts to understand in relation to
Collision Avoidance include (but are not limited to): Risk assessment; Right
of Way; Restricted visibility; interpreting lights and shapes; interpreting
sound and light signals. In the event of conflict, the IRPCS regulations
must take precedence. For more information on IRPCS / COLREGS, refer
to: IRPCS
Moving target graphics
Moving target graphics are used for targets moving at a speed greater than
2 kts.
188
1. Interception zone (Predicted area based on target's last reported
position)
2. Interception line
3. Target COG line
4. AIS Target (Last received position)
Stationary Target graphics
Stationary target graphics are used for targets moving at a speed less than
2 kts.
1. Interception zone (Predicted area based on target's last reported
position)
2. Stationary AIS Target (Last received position)