Module 19 - Electronic Navigation
Radar Set-up and Tuning
What you will learn
Prepare and monitor the fitted radar so target detection, bearings, ranges and tracker outputs are interpreted within known set-up and sensor limits.
Radar information is produced by the fitted antenna, set-up, range, clutter controls, heading input, motion mode and operator. Familiarity in clear weather is part of safe use, not optional polish.
Radar performance depends on the set-up. Range scale, gain, sea clutter, rain clutter, tuning, heading alignment, and display mode all affect what you see. A poorly tuned radar may miss small craft, buoys, squalls, or coastline detail.
Practice in good visibility so the crew can compare the radar picture with the real world. Identify how headlands, isolated rocks, ships, rain showers, and buoys appear on your own set. Do not wait until fog to learn the controls.
Build a clear-weather radar check
Before an overnight passage, the crew compare the radar picture with known coast, buoys, small craft and a rain shower.
1. Select range
Use a scale that supports both detection and the decision being made; scan other ranges as conditions require.
2. Optimise the picture
Adjust gain and clutter controls deliberately and check tuning or automatic modes on the fitted set.
3. Check alignment
Compare heading and bearing presentation with known objects and the steering compass.
4. Test tracking
Observe acquisition, stabilisation, target swap and loss behaviour before relying on vectors.
Sense check: A clean-looking display can be over-suppressed and miss the weak target the lookout most needs to detect.
Common mistake or limitation
- Excess sea or rain clutter suppression can remove real weak targets as well as clutter.
- One range scale does not provide the best picture for every detection and collision task.
- Incorrect heading or speed input can corrupt true vectors and tracker output.
- Learning the controls for the first time in fog adds avoidable workload and error.
Recap
- Practise on the fitted set in clear weather and compare echoes with the real scene.
- Use range, gain and clutter controls deliberately rather than to make the screen merely tidy.
- Check heading, speed and motion-mode inputs before trusting vectors.
- Continue lookout and systematic observation; radar does not replace them.
Optional quick check
Section 6 of 18
Why is turning sea-clutter suppression up until the display looks completely clean unsafe?
Sources and factual review
Reviewed 20 August 2026 - Compass Revision editorial review.
- RYA Yachtmaster Offshore examination scope
- RYA Coastal Skipper/Yachtmaster Offshore Theory course
- RYA Digital First: the rise of eNavigation
- MCA MGN 610 Amendment 1 — navigation and voyage planning
- MCA MGN 379 Amendment 1 — electronic navigational aids
- IMO Convention on the International Regulations for Preventing Collisions at Sea
Continue studying Electronic Navigation
This public lesson is part of Revision Module 19. Full revision access adds the guided Learn, Practise and Test flow, flashcards and revision progress.