Towing and pushing

A power-driven vessel when towing shall exhibit:

instead of the light prescribed in Rule 23(a)(i) or (a)(ii), two masthead lights in a vertical line. When the length of the tow, measuring from the stern of the towing vessel to the after end of the tow, exceeds 200 metres, three such lights in a vertical line;

sidelights;

a sternlight;

a towing light in a vertical line above the sternlight;

when the length of the tow exceeds 200 metres, a diamond shape where it can best be seen.

When a pushing vessel and a vessel being pushed ahead are rigidly connected in a composite unit they shall be regarded as a power-driven vessel and exhibit the lights prescribed in Rule 23.

A power-driven vessel when pushing ahead or towing alongside, except in the case of a composite unit, shall exhibit: two masthead lights in a vertical line; sidelights; a sternlight.

A vessel or object being towed, other than those mentioned in paragraph (g) of this Rule, shall exhibit: sidelights; a sternlight; when the length of the tow exceeds 200 metres, a diamond shape where it can best be seen.

Provided that any number of vessels being towed alongside or pushed in a group shall be lighted as one vessel: a vessel being pushed ahead, not being part of a composite unit, shall exhibit at the forward end sidelights; a vessel being towed alongside shall exhibit a sternlight and at the forward end sidelights.

Where from any sufficient cause it is impracticable for a vessel or object being towed to exhibit the lights or shapes prescribed in paragraph (e) or (g) of this Rule, all possible measures shall be taken to light the vessel or object towed or at least to indicate the presence of such vessel or object.