Clause 3 Horizontal positioning and spacing of lights

(1) When 2 masthead lights are prescribed for a power-driven vessel, the horizontal distance between them—

(a) must not be less than one-half of the length of the vessel; but

(b) need not be more than 100 metres.

The forward light must be placed not more than one quarter of the length of the vessel from the stem.

(2) On a power-driven vessel of 20 metres or more in length, the sidelights must not be placed in front of the forward masthead lights. They must be placed at or near the side of the vessel.

(3) When the lights prescribed in rules 22.27(2)(a) and 22.28 (all-round lights for vessels restricted in their ability to manoeuvre and vessels constrained by their draught) are placed vertically between the forward masthead light(s) and the after masthead light(s), these all- round lights must be placed at a horizontal distance of not less than 2 metres from the fore and aft centreline of the vessel in the athwartship direction.

(4) When only one masthead light is prescribed for a power-driven vessel, this light must be exhibited forward of amidships; except that a vessel of less than 20 metres in length need not exhibit this light forward of amidships but must exhibit it as far forward as practicable.