2. The master of every ship not admitted to free pratique shall exhibit on board his or her ship at the peak or other conspicuous place where it can be best seen, and at a height of not less than 20 feet above the hull of the ship, during the whole of the time between sunset and sunrise a night signal, consisting of 3 lights, which shall be arranged, at a distance of not less than 6 feet apart, in the form of an equilateral triangle, and of which the light at the apex of the triangle shall be white, and the other lights at the ends of the base of the triangle shall be red in colour.