Section 6    Target Tracking and AIS  6-16 
 
True vector mode 
In the true vector mode, the directions of vectors indicate the true courses of targets and the Vector 
Lengths indicate the values which are proportional to their speeds. 
In the true vector mode, the movements of other ships around own ship can be accurately and easily 
monitored. 
Vectors of own ship are displayed as shown below. 
 
Note 
In true vector mode, CPA ring cannot be displayed. 
 
 
 
Relative Vector Mode 
The relative vector does not represent the true motion of the target, but its relative relation with own 
ship. A target with its relative vector directed to own ship (passing through the CPA limit ring) will be a 
dangerous target. 
In the Relative Vector mode, it can be seen at a glance where the CPA limit of the dangerous target is. 
 
 
   
 
 
 
 
The true vector is not displayed. 
CPA ring 
 
Relative vector 
Example of Relative Vector Mode 
The relative vector is not displayed. 
Own ship's 
vector 
Example of True Vector Mode 
HL 
True vector