Radar plotting simulator
Practise relative motion, radar plotting and CPA/TCPA with an interactive workspace. Enter two radar observations, explore target tracks and compare geometric manoeuvre examples in radar and 3D views.
Radar plotting practical
2 encounters · 30 minutes · 100% required
Two encounters drawn by the server. Plot each one on the sheet above from own course and speed and two timed observations, then enter the target's true course and speed, the CPA and the TCPA from the second observation. Every answer must be within tolerance.
Tolerances: course ±3°, speed ±0.3 kn, CPA ±0.2 NM, TCPA ±2 min.
Proof of practice in an unproctored plotting exercise on a simulated relative-motion sheet. It is not a radar observer, ARPA or STCW qualification and does not assess the operation of real radar equipment.
Explore relative motion step by step
This workspace brings Cinemàtica's radar exercises into Navigation & Radar. Start with a demonstration or build an exercise using your own ship's course and speed, a target's bearings and ranges, and the observation times. Change one input at a time to see how the geometry responds.
- Record two echoes for the same target at different times. Check the bearing, range and clock entries before calculating; the observation interval is part of the relative-motion calculation.
- Read the relative track and the calculated closest point of approach (CPA) and time to CPA (TCPA). Compare the results with the plotted positions instead of treating a single number as a complete picture.
- Use playback and the 3D view to inspect the same encounter. Try an illustrative course or speed change, compare the resulting tracks, and save or duplicate the exercise to explore another case.
Understand what the exercise models
The simulator is an educational geometric model. Its manoeuvre examples do not determine every vessel's COLREG duties or represent a ship's real turning behaviour. Multiple targets are calculated independently. Use the linked rules to connect the exercise with risk assessment and avoiding action. Exercises are saved in this browser without requiring an account.