Module 16 - Pilotage
Clearing Bearings
On the chart, draw or imagine a line from a conspicuous object that clears the danger by the chosen margin. Measure its true bearing in the direction from the vessel towards the object, shade or label the danger side, and write an unambiguous instruction such as 'lighthouse not more than 025°T'. Test the wording from points on the intended route.
The suffix matters. A hand-bearing compass produces a compass bearing unless corrected; a plotter may display true or magnetic depending on configuration. Convert the planned limit for the instrument being used, or convert the observation, and label the result. Comparing 025°T directly with 025°C can erase the intended margin.
A clearing bearing is a limit, not a track to chase. Monitor it early enough to detect the trend, allow for observation error and vessel movement, and take the pre-briefed avoiding action before the boundary is crossed. Cross-check with depth, position and the physical scene because the object may be misidentified or obscured.
- Construct the boundary from a conspicuous object with a deliberate danger clearance
- Write both the limit direction—maximum or minimum—and the bearing reference
- Compare true, magnetic or compass bearings only after correct conversion
- Act on the trend before crossing the planned boundary
Optional quick check
Section 4 of 8
The plan says 'lighthouse not more than 025°T' and corrected bearings rise through 025°T. What does that mean?
Practice advanced pilotage controls
The complete pilotage module connects clearing bearings with transits, depths, lights, contingencies and a cockpit-ready plan.