Rule 21 Definitions

Definitions — International

(a) Masthead light means a white light placed over the fore and aft centreline of the vessel showing an unbroken light over an arc of the horizon of 225 degrees and so fixed as to show the light from right ahead to 22.5 degrees abaft the beam on either side of the vessel.

(b) Sidelights means a green light on the starboard side and a red light on the port side each showing an unbroken light over an arc of the horizon of 112.5 degrees and so fixed as to show the light from right ahead to 22.5 degrees abaft the beam on its respective side. In a vessel of less than 20 metres in length the sidelights may be combined in one lantern carried on the fore and aft centreline of the vessel.

(c) Sternlight means a white light placed as nearly as practicable at the stern showing an unbroken light over an arc of the horizon of 135 degrees and so fixed as to show the light 67.5 degrees from right aft on each side of the vessel.

(d) Towing light means a yellow light having the same characteristics as the “sternlight” defined in paragraph (c) of this Rule.

(e) All-round light means a light showing an unbroken light over an arc of the horizon of 360 degrees.

(f) Flashing light means a light flashing at regular intervals at a frequency of 120 flashes or more per minute.

Definitions — Canadian Modifications

(g) Special flashing light means a yellow light flashing at regular intervals at a frequency of 50 to 70 flashes per minute, placed as far forward and as nearly as practicable on the fore and aft centreline of a vessel and showing an unbroken light over an arc of the horizon of not less than 180 degrees nor more than 225 degrees and so fixed as to show the light from right ahead to abeam and not more than 22.5 degrees abaft the beam on either side of the vessel.

(h) Blue flashing light means a blue all-round light flashing at regular intervals at a frequency of 50 to 70 flashes per minute.