Rule 22 - Visibility of lights

Vessels of 50 meters or more in length:

Masthead light - white - 225°, from 22.5° abaft the beam on both sides - 6 miles

Port sidelight - red - 112.5° - 3 miles

Starboard side light - green - 112.5° - 3 miles

Stern light - White - 135° - 3 miles

Towing light - yellow - 135° - 3 miles

all around light - various - 360° - 3 miles

Changes for smaller ships

In vessels of 12 meters or more in length but less than 50 meters in length:

− a masthead light, 5 miles; except that where the length of the vessel is less than 20 meters, 3 miles;

− a sidelight, 2 miles;

− a sternlight, 2 miles;

− a towing light, 2 miles;

− a white, red, green or yellow all-round light, 2 miles.

In vessels of less than 12 meters in length:

− a masthead light, 2 miles;

− a sidelight, 1 mile;

− a sternlight, 2 miles;

− a towing light, 2 miles;

− a white, red, green or yellow all-round light, 2 miles

In inconspicuous, partly submerged vessels or objects being towed:
white all-round light, 3 miles