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Pilotage: transits, clearing bearings and leading lights

Pilotage is navigating by eye in close water: harbour entrances, rivers and rocky approaches, where there's no time to go below to the chart. It works because you plan it beforehand and then follow simple, visible references.

The tools

Transits

Two charted objects seen in line, such as a beacon and a church, or two leading marks. Keep them in line and you're on a known track, with no compass needed. If the near object appears to one side of the far one, you've drifted the other way: steer towards the near object to bring them back into line.

Leading lines and leading lights

Many harbours have purpose-built transits: two marks or lights, one higher and further away than the other, lined up to lead you down the safe channel. At night, keep the two lights one above the other.

Clearing bearings

A bearing on a charted object that marks the edge of safe water. Draw the line on the chart from the object, just clear of the danger, and note which side is safe: for example, “keep the lighthouse bearing more than 045° true”. Convert it to a compass bearing before you leave, so you can check it with a hand-bearing compass.

Sector lights

At night, a sector light shows white over the safe channel and red or green either side. If the colour changes, you're drifting out of the channel. See chart light characteristics.

Depth

The echo sounder, corrected for the height of tide, tells you when you're crossing a charted contour. It makes a useful extra check, especially in poor visibility.

Making a pilotage plan

  1. Study the chart and pilot book for the dangers, the marks, the tidal stream and any local rules or harbour calls.
  2. Break the approach into legs. For each one, note the mark or transit to follow, the course, the distance or time, and what tells you it's time to turn.
  3. Add the safety lines: clearing bearings and depth limits that tell you you're straying into danger.
  4. Write it down simply, in big writing, as a list or a sketch you can read in the cockpit in the rain. Number the marks in the order you'll see them.
  5. Plan for the tide: enough depth, and the effect of the stream across the entrance on your course.

Doing it

  • Brief the crew on the plan, and give someone the job of spotting the next mark.
  • Keep the plotter as a cross-check, not the main reference: your eyes and the plan come first.
  • If you're unsure where you are, slow down or stop and work it out. Don't press on hoping.

Test yourself, free

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Questions

What is a clearing bearing?

A bearing on a charted object that marks the edge of safe water. As long as the object's bearing stays on the safe side of the limit, for example more than 045° true, you're clear of the danger.

What is a transit in pilotage?

Two charted objects seen in line. Keeping them in line keeps you on a known track, with no compass error, and seeing them open tells you which way you've drifted.

What is a pilotage plan?

A short, written plan for entering or leaving a harbour: the marks you'll pass in order, the bearings and transits to follow, where to turn, the depth you expect, and the dangers to avoid, kept simple enough to read in the cockpit.

Free printable cheat sheets

Lights, day shapes, sound signals, buoyage, chart symbols and flags on 7 printable sheets. We'll email you the link.

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Last checked 5 November 2026. DeckPrep is an independent revision tool and is not affiliated with, endorsed by, or operated by the RYA. Always check current requirements with the RYA.