What four colours are used in lighted navigation aids?

• A. White, green, red, and yellow
• B. White, blue, red, and yellow
• C. White, green, blue, and red
• D. Red, green, yellow, and blue

Answer: (A)

Lighted navigation aids use a color code to convey different kinds of information to mariners. The four colors you’ll commonly see are white, green, red, and yellow. White lights are used for general or safe-water indications, helping you know when you’re in safe, open water or identifying certain marks. Green and red lights indicate the sides of a channel—green on the starboard (right) side and red on the port (left) side—telling you which way to pass when steering through a channel. Yellow lights mark special-purpose or caution marks, signaling that extra care or a specific instruction applies in that area.

The other colors (like blue, for example) aren’t standard for lighted navigation aids, so options that include those colors don’t fit typical navigation marking conventions.