Section 13 High-speed Craft

(a) The masthead light of high-speed craft may be placed at a height related to the breadth of the craft lower than that prescribed in subparagraph 2(a)(i) of this Annex, provided that the base angle of the isosceles triangles formed by the sidelights and masthead light, when seen in end elevation, is not less than 27°.

(b) On high-speed craft of 50 metres or more in length, the vertical separation between foremast and mainmast light of 4.5 metres required by subparagraph 2(a)(ii) of this Annex may be modified provided that such distance shall not be less than the value determined by the following formula:

y = [(a + 17ψ)C/1000] + 2

where

y is the height of the mainmast light above the foremast light in metres;

a is the height of the foremast light above the water surface in service condition in metres;

ψ is the trim in service condition in degrees; and

C is the horizontal separation of masthead lights in metres.

(c) The term high-speed craft means a craft that has been certified in accordance with the International Code of Safety for High Speed Craft, 2000 or the International Code of Safety for High-Speed Craft, 1994.