Module 16 - Pilotage
Lateral Marks
What you will learn
Use Region A normal and preferred-channel lateral marks in the charted direction of buoyage without inventing priority or passing too close.
Lateral marks describe channel sides. In Region A the port-hand side is red and the starboard-hand side is green when following the direction of buoyage; at a junction, one contrasting band and a 2+1 light rhythm identify a preferred channel.
A Region A port-hand mark is red and may be can-shaped or carry a can topmark; a starboard-hand mark is green and may be conical or carry a cone topmark. When lit, each uses its side colour. Numbers or letters may help identify the individual mark, but never rely on a universal odd/even rule where the chart and local system are the authority.
Travelling in the direction of buoyage, leave the port-hand mark to port and the starboard-hand mark to starboard. Travelling against that direction changes which side of the boat the marks appear on, not what the marks mean. Allow for stream, wind, traffic and the fact that the buoy may swing around its sinker.
At a junction, green with one broad red band indicates preferred channel to port; red with one broad green band indicates preferred channel to starboard. If lit, the characteristic is composite group flashing 2+1 in the mark's main colour. 'Preferred' does not guarantee that the other branch is unsafe or that the preferred branch suits this vessel—check depth, hazards and local directions.
Read the main lateral colour first, then the contrasting junction band.
| Region A mark | Day cues | Night cue if lit | Meaning in direction of buoyage |
|---|---|---|---|
| Port hand | Red; can shape/topmark when fitted | Red | Marks port side of channel |
| Starboard hand | Green; cone shape/topmark when fitted | Green | Marks starboard side of channel |
| Preferred channel to port | Green with one broad red band | Green Fl(2+1) | Preferred branch lies to port |
| Preferred channel to starboard | Red with one broad green band | Red Fl(2+1) | Preferred branch lies to starboard |
Read a junction mark before choosing the branch
Following the direction of buoyage, the yacht approaches a mainly green mark with one broad red horizontal band. The chart shows a shoal in the branch to starboard.
1. Read the main colour
Mainly green means the mark is modified from the Region A starboard-hand lateral family.
2. Read the band
The red band makes it preferred channel to port, matching the charted safer branch for this plan.
3. Verify suitability
Check the actual depth, traffic and local direction before taking the port branch; the mark does not guarantee conditions.
Sense check: If the red band is read as a red port-hand mark, the preferred branch is reversed—the main body colour must lead the identification.
Common mistake or limitation
- Preferred-channel marks are read by main colour plus contrasting band, not by the band alone.
- A correctly identified lateral mark is not a target to shave closely; buoy movement, current and traffic still require clearance.
Recap
- Use Region A colour and shape together in the charted direction of buoyage.
- Read a 2+1 junction mark from its main colour before the band.
- Confirm branch depth, hazards and rules rather than treating 'preferred' as permission.
Optional quick check
Section 6 of 8
In Region A, what does a mainly green mark with one broad red horizontal band indicate?
Continue studying Pilotage
This public lesson is part of Revision Module 16. Full revision access adds the guided Learn, Practise and Test flow, flashcards and revision progress.