22.22 Visibility of lights
Maritime Rules Part 22: Collision Prevention
Lights must have an intensity as specified in Appendix 1 of this Part. They must be visible at the following minimum ranges.
(1) In vessels of 50 metres or more in length— a masthead light, 6 miles: a sidelight, 3 miles: a sternlight, 3 miles: a towing light, 3 miles: a white, red, green or yellow all-round light, 3 miles.
(2) In vessels of 20 metres or more in length but less than 50 metres in length— a masthead light, 5 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.
(3) In vessels of 12 metres or more in length but less than 20 metres in length— a masthead light, 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
(4) In vessels of less than 12 metres 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.
(5) In inconspicuous, partly submerged vessels, or objects being towed— a white all-round light, 3 miles.
(6) The signal light prescribed under rule 22.34 for signalling a manoeuvre— a white all-round light, 5 miles.