Lights and Shapes - Rule 21 Masthead light White 225 º Sidelights A green light on the starboard side A red light on the port side 112.5 º Stb. 112.5 º Port Sternlight White 135 º Towing light Yellow 135 º All-round light 360 º Flashing light Frequences of 120 flashes or more per minute Shapes Ball Cylinder Cone Diamond Flag A