Radar Simulator
A small-boat radar with every control live. Work through twelve missions, from setting the gain to judging a ship’s closest point of approach in fog, or take the set out in free play. When you can use it, test yourself in the Weather & Radar ID game.
What each radar control does
- Range:
- How far the screen reaches. Each range has its own ring spacing, shown in the top-right corner. Use the shortest range that shows what matters, and range out regularly.
- Gain:
- Receiver sensitivity. Turn it up until a light speckle just shows, then back off slightly. Too low hides small targets; too high hides everything in noise.
- Tune:
- Matches the receiver to the transmitter. Adjust for the longest tune bar or the strongest echoes. Most sets do it automatically.
- Sea clutter (STC):
- Reduces the gain close to the boat, where waves return echoes. Use just enough to see targets through it: overdone, it wipes out small boats nearby.
- Rain clutter (FTC):
- Breaks up large, soft echoes such as rain to their leading edge, so hard targets inside a shower show. Turn it off again once the shower has passed.
- EBL:
- Electronic bearing line from the centre. Reads relative bearing in head-up and true bearing in north-up.
- VRM:
- Variable range marker: a ring you lay on the inner edge of an echo to read its range.
- Head-up / north-up:
- Head-up puts your heading at the top, like the view ahead. North-up puts north at the top, like the chart. The heading line shows which way the bow points.
- Trails:
- Show where each echo has been. In relative motion a trail pointing at the centre means a collision course.
Setting up a radar picture
- Switch on, wait for the set to warm up, then transmit.
- Choose a medium range, such as 3 or 6 miles.
- Set the gain for a light background speckle, and check the tune.
- Add sea clutter control until the waves near the centre thin out, but no further.
- Use rain clutter control only while a shower is on the screen.
- Check the heading line, orientation and ring spacing before you measure anything.
Collision avoidance by radar
COLREGs Rule 7 requires proper use of radar, including long-range scanning and systematic observation of detected objects. A steady bearing with a closing range means risk of collision. In restricted visibility (Rule 19), a vessel detected by radar alone forward of the beam calls for early, bold action, but avoid altering to port for it unless it is being overtaken, and avoid turning towards a vessel abeam or abaft the beam. Radar does not replace a lookout: small craft, wooden boats and targets in clutter may not show at all.
This simulator is a learning aid with simplified physics. Real sets differ in their controls and menus: read your own radar’s manual and take the RYA Radar course before relying on one at sea.