Boat basics
What Does Port and Starboard Mean on a Boat?
Published · Last checked October 2026
Port is the left-hand side of a boat and starboard is the right-hand side, always when you are standing aboard and facing the bow (the front). Because they are fixed to the boat, not to the person speaking, they never change meaning when someone turns around. Port is marked by a red navigation light and starboard by a green one. A handy memory aid: 'port' and 'left' both have four letters, and 'there's a little red port left in the bottle'.
Why not just say left and right?
Left and right depend on which way you face. If the helm faces aft to look at a following sea while the foredeck crew faces forward, 'left' means opposite things to each of them. Port and starboard belong to the boat, so an instruction like 'fender on the starboard side' means one thing to everyone aboard, and to the marina staff on the pontoon as well.
Where the words come from
Before rudders were hung on the stern, ships were steered by a large oar, the 'steer board', over the right-hand side. That side became 'starboard'. To keep the steering oar clear of the quay, ships tied up with their left side against the harbour wall, so the left became the 'port' side. The older word 'larboard' was dropped in the nineteenth century because it sounded too like starboard when shouted in a gale.
Related terms you will hear
| Term | Meaning |
|---|---|
| Bow / forward | The front of the boat, or towards it |
| Stern / aft | The back of the boat, or towards it |
| Port | Left side, facing forward (red light) |
| Starboard | Right side, facing forward (green light) |
| Abeam | At right angles to the boat's centreline |
| On the port quarter | Behind and to the left, roughly 45 degrees off the stern |
| Port tack / starboard tack | Wind coming over the port or starboard side |
Why it matters for safety
- Navigation lights: at night a red light means you are looking at a vessel's port side and a green light its starboard side, which tells you which way it is heading. See the navigation lights guide.
- Rules of the road: under the COLREGs a sailing boat on port tack keeps clear of one on starboard tack, and a power vessel keeps clear of another crossing from its starboard side.
- Clear instructions: 'Rock to port' or 'man overboard, starboard side' is unambiguous in a moment of stress.
The terms are covered early in the points of sail lesson and come back constantly in the rules of the road.