(a) Two masthead lights one above the other about 1 m apart, placed forward and in the axis of the vessel, the upper light being at a height of, at least, 5 meters and the lower light, so far as possible, at least 1 m higher than the side lights;
(b) The side lights prescribed in article 3.08, paragraph 1 (b);
(c) A yellow instead of a white stern light, placed in the axis of the vessel and high enough to be clearly visible from the towed unit following the vessel or the motorized vessel, pushed convoy or side-by-side formation in front of which the vessel is used as an auxiliary;
A yellow cylinder, with two black and white stripes at top and bottom, the white stripes being at the ends of the cylinders. The cylinder shall be placed vertically forward, and high enough to be visible from all directions.
2. Where a towed convoy is led by several motorized vessels, or where a motorized vessel, pushed convoy or side-by-side formation is preceded by several auxiliary motorized vessels proceeding side-by-side, whether coupled or not, each of those vessels shall carry:
Instead of the masthead lights prescribed in 1 (a) above, three masthead lights one above the other about 1 m apart, placed forward in the axis of the vessel, the top and bottom lights being at the same height as those prescribed in paragraph 1 (a);
The cylinder prescribed in paragraph 1 above.
3. Vessels in a towed convoy following the motorized vessel or vessels referred to in paragraphs 1 and 2 above shall carry:
A bright white light visible from all directions, placed at a height of at least 5 m. This height may be reduced to 4 m for vessels whose length does not exceed 40 m;
A yellow ball in a suitable position and high enough to be visible from all directions.
(a) If a section of the convoy is more than 110 m long, that section shall carry two such lights, one forward and one aft;
(b) If a section of the convoy comprises a row of more than two vessels coupled side-by-side, only the two outside vessels of the row shall carry such lights or such a ball.
The marking of all towed vessels in a convoy shall so far as possible be carried at the same height above the water level.
4. The vessel or vessels forming the last section of a towed convoy shall carry, in addition to the marking prescribed in paragraph 3 above:
The stern light prescribed in article 3.08, paragraph 1 (c).
However, if the convoy ends with a row of more than two vessels coupled side-by-side, only the two outside vessels of the row shall carry such lights. If the rear of the convoy is made up of small craft, those craft shall not be taken into account for the provisions of this paragraph.
5. Where the vessels referred to in paragraph 3 above are seagoing vessels coming directly from or leaving for the sea, they may carry:
Instead of the white light, the side lights prescribed in article 3.08,
paragraph 1 (b);
The yellow ball.
6. The provisions of this article shall not apply to small craft towing only other small craft or to the towing of small craft.