Module 1 - Nautical Terms
Port and Starboard
Face the bow: port is the vessel's left side and starboard is its right side. The names do not swap when you turn to face aft, cross the cockpit or look at the vessel from ashore.
Under the COLREGs, a vessel's port sidelight is red and its starboard sidelight is green. Those light colours identify the vessel's sides; they are not instructions about which side of another vessel to pass.
Lateral marks belong to the IALA buoyage system and depend on the applicable region and direction of buoyage. In Region A, port-hand marks are red and starboard-hand marks green in the direction of buoyage; Region B reverses those lateral-mark colours. Vessel sidelights do not reverse between those regions.
- Port — left side when facing forward (red)
- Starboard — right side when facing forward (green)
Watch for this: Remember: 'port' and 'left' both have four letters.
Optional quick check
Section 2 of 9
You turn to face the stern. What happens to the vessel's port side?
Sources and factual review
Reviewed 20 August 2026 - Compass Revision editorial review.
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