6-57  Section 6    Target Tracking and AIS 
 
 
 
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An alert is displayed in the alert notification area (upper right of the screen). 
 
 
 
 
 
6.7.1  Danger target alarm (CPA/TCPA) 
 
 
Since these alarms may include some errors depending on the target tracking 
conditions, the navigation officer himself should make the final decision for ship 
operations such as collision avoidance. 
Making the final navigation decision based only on the alarm may cause accidents 
such as collisions.
 
 
In this system, targets are categorized into two types: tracked targets and dangerous targets 
depending on the danger level. The danger level can easily be recognized on the display at a glance. 
So, it is easily possible for the ship operator to judge which target is to be cautious about. 
 
The danger target symbol of the tracked target will be displayed until either the tracking is stopped or 
the conditions no longer apply. 
 
Alert notification 
area