Lesson previewRadar as a Pilotage Aid1 section shown
Preview lesson
Radar as a Pilotage Aid
What you will learn
Place radar observations inside a prepared pilotage plan with independent position, depth, progress, margin and abort checks.
Radar can monitor a plan when visual references are weak, but it cannot invent a safe route, identify every echo or show along-track progress from one parallel index.
Prepare the pilotage before workload rises. Mark the intended track, wheel-over or decision points, safe-water limits, charted dangers, suitable radar-conspicuous fixed objects, expected parallel-index and range signatures, position-fix opportunities, depth expectations, communications and a place where the approach can be paused or abandoned.
Radar supplies measured range, bearing and echo movement conditional on set-up, target definition and sensor alignment. A parallel index can show cross-track displacement; a radar range or fix can help locate progress. Neither proves the feature identity, depth, safe water or the continuing validity of the route. Keep chart, position, depth, sight, hearing and other independent evidence in the loop.
Set a speed that leaves time to detect, interpret, communicate and respond before a limit is reached. Brief which person conns, monitors radar, checks position/depth and keeps lookout where crew are available. If the expected picture is absent or inconsistent, preserve safe water and rebuild the picture before committing to confined water.
Radar pilotage board
Release the next action only when every relevant gate agrees
Compare four fictional cases. Observation, plan check, decision and stop boundary stay available as text as well as a schematic.
1 · Observation
One correct PI supports lateral position only
The headland echo is moving along the prepared 0.8 M parallel index. The separate wheel-over range remains 1.7 M.
2 · Plan check
Feature identity, heading, orientation and PI reference are coherent. Depth and an independent position check match the expected leg.
3 · Decision
Maintain the planned leg and speed while monitoring the PI, the reducing wheel-over range, depth and wider traffic picture.
4 · Stop boundary
Do not call the wheel-over from the PI. It constrains cross-track offset, not progress along the track.
Keep route progress, cross-track margin, hazard clearance and sensor validity separate before releasing the next pilotage action.
Worked example
A fictional approach follows 090°T towards a turn at waypoint B. A headland echo should track along a 0.8 M parallel index, while a separate lighthouse range should reduce to 1.2 M at the wheel-over check.
- 1Confirm the headland and lighthouse from charted relationship, range, bearing and other available evidence before using either cue.
- 2Use the PI echo to monitor lateral clearance, but use the lighthouse range and an independent position/depth check to judge progress towards B.
- 3If the PI is satisfactory but the 1.2 M wheel-over range never appears when expected, do not infer that the vessel is still before B; slow or hold safe water and resolve the mismatch.
Sense check: Being the correct distance off one coast says where the vessel is sideways, not where it is along that coast.
| Pilotage question | Useful radar evidence | Required separate check |
|---|---|---|
| Am I holding the planned lateral corridor? | Fixed echo relative to a prepared PI line | Feature identity, orientation, heading and offset |
| How far have I progressed? | Range/bearing fix or range trend to known features | Charted along-track position and next decision point |
| Am I outside danger? | Prepared clearing range or boundary | Hazard geometry, uncertainty, depth and reaction margin |
| May I continue? | Expected fixed and moving radar picture | Lookout, position, depth, traffic, plan validity and abort room |
Brief the evidence before the leg
A crew member must be able to challenge the con before visual references disappear.
1. Route
Name the leg, next decision point, expected speed and water that remains safe.
2. Lateral check
Name the PI or clearing constraint, reference object, expected side and intervention limit.
3. Progress check
Name the range, fix, depth or visual cue that identifies along-track position.
4. Stop rule
State the mismatch, workload or margin trigger that pauses or aborts the approach.
Sense check: A usable brief tells the monitor what should happen next and what evidence would stop it.
Common mistake or limitation
- Treating a plausible radar coastline as proof of position and safe water.
- Using one PI line as both cross-track and along-track position evidence.
- Entering confined water before agreeing an abort point and task split.
Recap
- Radar monitors a prepared plan; it does not create one.
- Cross-track, progress, depth and traffic need distinct evidence.
- Safe speed must preserve interpretation and response time.
- An unresolved picture is a reason to preserve safe water, not press on.
Optional quick check
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