8.—(1) Subject to regulation 9, where a vessel is carrying a dangerous substance specified in Schedule 3 in at least the quantity, if any, specified in that Schedule, the master of that vessel shall ensure that it displays–
(a)in the case of a vessel with a mast–
(i)during the day between sunrise and sunset, a flag complying with the requirements of Parts I and II of Schedule 4, and
(ii)when moored or anchored at night between sunset and sunrise and also during the day in restricted visibility an all-round red light giving a clear, uniform and unbroken light visible in conditions of good night-time visibility all round the horizon for a distance of at least 2 nautical miles;
(b)in the case of a vessel without a mast–
(i)during the day between sunrise and sunset, a flag complying with the requirements of Parts I and III of Schedule 4, and
(ii)when moored or anchored at night between sunset and sunrise and also during the day in restricted visibility, an all-round red light.
(2) Any flag or light required by paragraph (1) to be displayed shall be positioned so as to be as conspicuous as is reasonably practicable and, in the case of a light, so that it is above any other light being displayed by the vessel.
(3) it shall be a sufficient compliance with this regulation if–
(a)when a dumb craft is being towed, the towing vessel displays the flag required under the foregoing paragraphs; or
(b)when a dumb craft is moored or anchored that flag or light is displayed by an attendant vessel.