What colors are used in sidelights on vessels?

Sidelights on vessels are crucial for nighttime navigation and helping to prevent collisions. These lights are specifically designed to indicate the direction a vessel is facing, allowing other boats to understand its orientation. The correct colors used for sidelights are red and green.

The red light is positioned on the port (left) side of the vessel, while the green light is on the starboard (right) side. These colors serve a significant purpose: when viewed at night, a red light indicates the presence of a vessel on the port side, and a green light indicates a vessel is on the starboard side. This color-coding helps mariners determine the relative position of other vessels in the vicinity, contributing to safe navigation on the water.

The other color combinations mentioned do not align with maritime navigation standards for sidelights. Red and white, as well as blue and green, do not represent the internationally recognized colors for sidelights, which are specifically red and green. Yellow is typically used for specific signals or markers, not for sidelights on vessels.