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Lesson 3: Essential Lights and Shapes

Boating Essentials · Lesson 3 of 6

Read the night: essential lights and shapes

Navigation lights form a visual language. They help you infer a vessel’s aspect, direction and activity—but only when you observe the complete pattern.

⏱ 15–20 minutes◎ Beginner✓ 3 knowledge checks
By the end, you can…
  • Connect red with port, green with starboard and white with fore/aft sectors.
  • Use visible colours to form a cautious first interpretation.
  • Explain why one light alone cannot assign responsibilities.
01 · SEE IT

Colour reveals the side you can see

Power-driven vessel at night showing red, green and white navigation lights
An approaching power-driven vessel may show both sidelights and a white masthead light. Arrangements vary with vessel size and configuration.
Red sidelight

Marks the vessel’s port side over a forward sector.

Green sidelight

Marks the starboard side over a forward sector.

White masthead light

Shown by power-driven vessels underway over a forward sector; exact arrangements vary.

White sternlight

Shows aft. White can have other meanings, so read the whole pattern.

02 · CONNECT IT

Reuse the Lesson 1 anchors

Port—the drink—is red. Port and left both have four letters. The other sidelight is green on starboard. Both red and green suggest you are looking toward the bow; red plus an appropriate white suggests the port aspect, while green plus white suggests starboard.

Say “suggests,” not “proves.” Background lights, obscuration, status and viewing angle can mislead you.
PORT
red▲bowSTARBOARD
greenWHITE ASTERN
03 · USE IT

Build meaning in three passes

Inventory

Which colours, how many, and how are they arranged?

Aspect

Which side might you see, and is the bearing changing?

Status

Could the pattern indicate sailing, towing, fishing, restriction or anchoring?

Verify

Observe longer, use all means and apply the correct rules.

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Worked example

You see red and white

Your first hypothesis is the other vessel’s port aspect. Test it: is the pattern complete, what are bearing and range doing, and are other lights visible? Never declare stand-on or give-way from two colours alone.

04 · RETRIEVE IT

Check your understanding

1. You see red and green sidelights. Which aspect?
Broadly the bow or forward aspect. Continue observing the full pattern and movement.
2. Does one white light always mean a sternlight?
No. It may be a masthead, stern, all-round, anchor or another prescribed white light.
3. When are prescribed lights shown?
Sunset to sunrise, and in restricted visibility and other circumstances required by Rule 20. Prescribed shapes are carried by day.
05 · DO IT

Dockside light walkaround

  1. Safely identify each installed light.
  2. State colour and intended sector.
  3. Check for damage or obstruction.
  4. Predict the view from ahead, abeam and astern.
Lesson takeaway

Colour gives aspect; the complete pattern gives meaning. Observe, hypothesise and verify.

Educational information only. Consult current Navigation Rules for your vessel and operation.