Left and right at sea are fixed by facing forward. Port side is the left side of a ship when looking toward the bow.

The term avoids the ambiguity of “left” when people face different directions. Port is associated with the color red in navigation lights and lateral buoyage in many systems. Helm orders and collision-avoidance language use port and starboard exclusively.

New crew members learn port and starboard until the terms become automatic. Mistaking one for the other during berthing or collision avoidance can have serious consequences. The corresponding right side is starboard.

• Left side of the ship when facing forward
• Associated with red navigation lighting
• Used in standard helm and traffic language
• Opposite of starboard