Furuno FMD-3200 Operator's Manual page 235

Relative vector
Relative vectors on targets that are not moving over the ground such as land, naviga-
tional marks and ships at anchor will represent the reciprocal of own ship's ground
track. A target whose vector passes through own ship is on a collision course. (Dotted
lines in the figure are for explanation only.)
TT
Buoy
Own Ship
AIS
True vectors in ground
stabilization
To set the vector, click the vector time and vector reference indications in the [TT/AIS]
page to set them.
Vector time
13. TRACKED TARGET (TT) FUNCTIONS
Current
TT
(Set and drift)
Buoy
Own Ship
AIS
True vectors in sea
stabilization
Vector
reference
TT
Buoy
Own Ship
AIS
Relative vectors
13-5