Rule 25 covers lights for sailing vessels and vessels under oars.
An interactive 3D illustration is shown here. The same content is described in the rule text and key takeaways below.
Recognition Sequence
Classify the vessel state first: underway, making way, stopped, at anchor, aground, towing, fishing, pilotage or special condition.
Read special lights vertically from top to bottom before using sidelights and sternlight to confirm aspect.
Then confirm the answer with the day shape, vessel length and any extra signal such as towing lights, deck illumination or a cylinder.
Exam Focus
Avoid identifying a vessel from one colour alone.
Many mistakes come from spotting a red light and guessing before checking the full pattern.
If the question mentions 'making way', 'underway but stopped', 'at anchor' or 'aground', that wording usually determines which extra lights or shapes appear.
Key Takeaways
Sailing vessels show sidelights and sternlight only (no masthead light)
Optional red-over-green all-round lights at masthead
Small sailing vessels may combine lights in one lantern
Vessels under oars need at minimum a white light ready
Common Mistakes
Expecting a masthead light on a sailing vessel
Confusing optional red/green masthead lights with required lights
Test Your Knowledge
Test your knowledge and prove your mastery.
More rules in this Part
- Visibility of LightsSpecifies minimum visibility ranges for lights based on vessel length.
- Power-driven Vessels UnderwayPower-driven vessels underway shall exhibit masthead light(s), sidelights, and sternlight. Vessels 50m+ require two masthead lights.
- Vessels Not Under Command or Restricted in Ability to ManoeuvreNUC shows two red all-round lights vertically. RAM shows red-white-red all-round lights vertically.
- Vessels Constrained by Their DraughtA vessel constrained by draught may display three all-round red lights in a vertical line, or a cylinder day shape.
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