Why they matter
Navigation lights tell other skippers what you are, which way you are heading and whether you are under way. The rules come from the International Regulations for Preventing Collisions at Sea (COLREGs), which Gulf authorities apply.
Sidelights
Red on the port (left) side and green on the starboard (right) side, each showing from dead ahead to just behind the beam. On small boats they can be combined in one bicolour lantern at the bow.
Masthead and stern lights
A white masthead light shows forward; a white sternlight shows aft. A power-driven boat under 12 metres may instead show one all-round white light together with its sidelights.
Visibility ranges for boats under 12 metres
Masthead light 2 nautical miles, sidelights 1 nautical mile, sternlight 2 nautical miles, all-round light 2 nautical miles. Check the range printed on the light before you buy.
LED or bulb
LED lights draw far less power, last much longer and handle vibration better. If you replace bulbs in an existing light, use the bulb type the light was approved with, or the certified range may no longer apply.
Before you buy
Confirm your boat's length and whether it is power or sail, check the mounting (side, deck or pole) and the voltage, and check local requirements with your maritime authority.