Left And Right Channel Markers - Channel Markers These Show Well-established Channels And Indicate Port (left) And Starboard (right) Sides Of The Channels. Port Marks A Red Can Shape. At Night, A Red Flashing Light May Be Shown. Starboard Mark A Green Conical Shape. At Night A Green Flashing Light Maybe Shown. Coming In Rule When Entering Harbour (up Stream) The Red Port Mark Should Be Kept On The Boat's Port (left) Side The Green Mark On The Boat's Starboard (right) Side. Going Out Rule When Leaving Harbour (down Stream) The Red Port Mark Should Be Kept On The Boat's Starboard (right) Side And The Green Mark On The Boat's Port (left) Side. Photo