The master of every ship having explosives on board shall, whilst the ship is within the limits of the harbour, keep conspicuously exhibited at the fore, by day, a red flag (B. International Code), and, in addition to the lights ordinarily required by night and in such a position as to be above them, a red light showing a clear uniform unbroken light all round the horizon visible on a clear night at a distance of one kilometre from such ship.
