COG 
Course Over Ground 
The direction of the ship's movement relative to the earth, measured 
on board the ship, expressed in angular units from true north 
 
 
CORREL 
CORRELation 
 
 
CPA/TCPA 
The distance to the Closest Point of Approach    and Time to the 
Closest Point of Approach.    Limits are set by the operator and are 
related to own ship. 
 
 
CTW 
Course Through Water 
The direction of the ship's movement through the water 
D 
DRIFT 
The current velocity for manual correction or the current speed on the 
horizontal axis of the 2-axis log is displayed. 
E 
EBL 
Electronic Bearing Line 
An electronic bearing line originated from own ship’s position. 
 
 
ETA 
Estimated Time of Arrival 
G 
Ground 
stabilization  
A display mode in which speed and course information are referred to 
the ground, using ground track input data. 
H 
HDG 
Heading 
The horizontal direction that the bow of a ship is pointing at any 
instant, expressed in angular units from a reference direction . 
 
 
HL 
Heading line 
A graphic line on a radar presentation drawn from the consistent 
common reference point to the bearing scale to indicate the heading 
of the ship   
 
 
HSC 
Vessels which comply with the definition in SOLAS for high speed 
craft 
 
 
H up 
Head up 
Own ship’s heading line is always pointed to the top center of the 
radar display. 
I 
IMO 
International Maritime Organization 
 
 
Interswitch Unit 
A device to switch over two or more radar display units and two or 
more scanners. 
 
 
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