COLREGs Rule 24: Lights and shapes for towing and pushing

Last reviewed: October 14, 2026

Rule 24 covers the lights and shapes shown by power-driven vessels that tow or push, and by the vessels or objects they tow. A towing vessel shows two masthead lights, or three if the tow exceeds 200 meters, plus sidelights, a sternlight and a towing light. International and Inland rules differ for pushing ahead, towing alongside, groups of vessels and the Western Rivers.

Applies toPower-driven vessels towing or pushing, and vessels or objects being towed or pushed.

What it says

A power-driven vessel towing must show two masthead lights in a vertical line instead of the Rule 23(a)(i) or (a)(ii) light. It must show three such lights if the tow exceeds 200 meters. Inland applies this to towing astern.
COLREGs Rule 24(a)(i)“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 meters, three such lights in a vertical line;”
A pushing vessel and a vessel pushed ahead that are rigidly connected in a composite unit are regarded as a power-driven vessel and must show the lights prescribed in Rule 23.
COLREGs Rule 24(b)“they shall be regarded as a power-driven vessel and exhibit the lights prescribed in Rule 23.”
International: A power-driven vessel pushing ahead or towing alongside, except a composite unit, must show two masthead lights in a vertical line, sidelights and a sternlight.
COLREGs Rule 24(c)“A power-driven vessel when pushing ahead or towing alongside, except in the case of a composite unit, shall exhibit:”
Inland: A power-driven vessel pushing ahead or towing alongside must show two masthead lights in a vertical line, sidelights and two towing lights in a vertical line, except as paragraphs (b) and (i) require and except where paragraph (j) applies.
COLREGs Rule 24(c)“A power-driven vessel when pushing ahead or towing alongside, except as required by paragraphs (b) and (i) of this Rule, shall exhibit:”
A vessel or object being towed, other than those in paragraph (g), must show sidelights and a sternlight. It must also show a diamond shape where it can best be seen when the length of the tow exceeds 200 meters.
COLREGs Rule 24(e)(iii)“(iii) when the length of the tow exceeds 200 meters, a diamond shape where it can best be seen.”
Inland: A vessel pushed ahead that is not part of a composite unit must show sidelights and a special flashing light at the forward end.
COLREGs Rule 24(f)(i)“shall exhibit at the forward end, sidelights and a special flashing light.”
When a towed vessel or object cannot show the prescribed lights or shapes for a sufficient cause, all possible measures must be taken to light it or at least to indicate its presence.
COLREGs Rule 24(h)“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.”
Inland: On the Western Rivers (except below the Huey P. Long Bridge at mile 106.1 Above Head of Passes on the Mississippi River) and on waters specified by the Secretary, a vessel pushing ahead or towing alongside must show sidelights and two towing lights in a vertical line, except as paragraph (b) applies.
COLREGs Rule 24(j)“a power-driven vessel when pushing ahead or towing alongside, except as paragraph (b) of this Rule applies, shall exhibit:”

Common questions

How many masthead lights must a towing vessel show?

A power-driven vessel towing must show two masthead lights in a vertical line. It must show three such lights if the length of the tow exceeds 200 meters.

“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 meters, three such lights in a vertical line;”

When does a towed vessel show a diamond shape?

A vessel or object being towed shows a diamond shape where it can best be seen when the length of the tow exceeds 200 meters.

“(iii) when the length of the tow exceeds 200 meters, a diamond shape where it can best be seen.”

How is a pushing vessel in a composite unit lighted?

A pushing vessel and a vessel pushed ahead that are rigidly connected in a composite unit are regarded as a power-driven vessel. They show the lights prescribed in Rule 23.

“they shall be regarded as a power-driven vessel and exhibit the lights prescribed in Rule 23.”

Can a vessel not normally engaged in towing skip the towing lights when assisting a vessel in distress?

Where it is impracticable for a sufficient cause, such a vessel is not required to show those lights when towing another vessel in distress or otherwise in need of assistance.

“such vessel shall not be required to exhibit those lights when engaged in towing another vessel in distress or otherwise in need of assistance.”

The text of COLREGs Rule 24

U.S. Coast Guard, Navigation Rules and Regulations Handbook

Rule 24: Towing and Pushing

International (COLREGs)

(a) A power-driven vessel when towing shall exhibit:

(i) 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 meters, three such lights in a vertical line;

(ii) sidelights;

(iii) a sternlight;

(iv) a towing light in a vertical line above the sternlight; and

(v) when the length of the tow exceeds 200 meters, a diamond shape where it can best be seen. Power-driven vessel towing astern—towing vessel less than 50 meters in length; length of tow exceeds 200 meters. Same for Inland

(b) 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. Composite unit underway. Same for Inland.

(i) instead of the light prescribed in Rule 23(a)(i) or 23(a)(ii), two masthead lights in a vertical line;

(ii) sidelights; and

(iii) a sternlight. Power-driven vessel pushing ahead or towing alongside— towing vessel less than 50 meters in length. International only.

(d) A power-driven vessel to which paragraph (a) or (c) of this Rule applies shall also comply with Rule 23(a)(ii). Power-driven vessel towing astern—length of tow 200 meters or less. The after masthead light is optional for vessel less than 50 meters in length. Same for Inland.

(e) A vessel or object being towed, other than those mentioned in paragraph

(g) of this Rule, shall exhibit:

(i) sidelights;

(ii) a sternlight;

(iii) when the length of the tow exceeds 200 meters, a diamond shape where it can best be seen. Vessel or object being towed—length of tow exceeds 200 meters. Same for Inland.

(f) Provided that any number of vessels being towed alongside or pushed in a group shall be lighted as one vessel:

(i) a vessel being pushed ahead, not being part of a composite unit, shall exhibit at the forward end, sidelights;

(ii) a vessel being towed alongside shall exhibit a sternlight and at the forward end, sidelights. Vessel being pushed ahead, not being part of a composite unit. International only. Vessel being towed alongside. International only.

(g) An inconspicuous, partly submerged vessel or object, or combination of such vessels or objects being towed, shall exhibit:

(i) if it is less than 25 meters in breadth, one all-round white light at or near the forward end and one at or near the after end except that dracones need not exhibit a light at or near the forward end;

(ii) if it is 25 meters or more in breadth, two additional all-round white lights at or near the extremities of its breadth;

(iii) if it exceeds 100 meters in length, additional all-round white lights between the lights prescribed in subparagraphs (i) and (ii) so that the distance between the lights shall not exceed 100 meters;

(iv) a diamond shape at or near the aftermost extremity of the last vessel or object being towed and if the length of the tow exceeds 200 meters an additional diamond shape where it can best be seen and located as far forward as is practicable.

(h) 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.

(i) Where from any sufficient cause it is impracticable for a vessel not normally engaged in towing operations to display the lights prescribed in paragraph (a) or

(c) of this Rule, such vessel shall not be required to exhibit those lights when engaged in towing another vessel in distress or otherwise in need of assistance. All possible measures shall be taken to indicate the nature of the relationship between the towing vessel and the vessel being towed as authorized by Rule 36, in particular by illuminating the towline

Inland Rules

Towing and pushing

(a) A power-driven vessel when towing astern shall exhibit:

(i) Instead of the light prescribed either in Rule 23(a)(i) or 23(a)(ii) (§§ 83.23(a)(i) and (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 meters, three such lights in a vertical line;

(ii) Sidelights;

(iii) A sternlight;

(iv) A towing light in a vertical line above the sternlight; and

(v) When the length of the tow exceeds 200 meters, a diamond shape where it can best be seen. Power-driven vessel towing astern—towing vessel less than 50 meters in length; length of tow 200 meters or less. Same for International.

(c) A power-driven vessel when pushing ahead or towing alongside, except as required by paragraphs (b) and (i) of this Rule, shall exhibit:

(i) Instead of the light prescribed either in Rule 23(a)(i) or 23(a)(ii) (§ 83.23)(a)(i) and (ii), two masthead lights in a vertical line;

(ii) Sidelights; and

(iii) Two towing lights in a vertical line. Power-driven vessel pushing ahead or towing alongside—towing vessel less than 50 meters in length. Inland only.

(d) A power-driven vessel to which paragraphs (a) or (c) of this Rule applies shall also comply with Rule 23(a)(i) and 23(a)(ii) (§ 83.23(a)(i) or (ii)). Power-driven vessel towing astern—length of tow 200 meters or less. When masthead lights for towing or pushing are exhibited aft, a forward masthead light is required. Same for International.

(e) A vessel or object other than those referred to in paragraph (g) of this Rule being towed shall exhibit:

(i) Sidelights;

(ii) A sternlight; and

(iii) When the length of the tow exceeds 200 meters, a diamond shape where it can best be seen. Vessel being towed—length of tow 200 meters or less. Same for International.

(f) Provided that any number of vessels being towed alongside or pushed in a group shall be lighted as one vessel, except as provided in paragraph (f)(iii) of this Rule.

(i) A vessel being pushed ahead, not being part of a composite unit, shall exhibit at the forward end, sidelights and a special flashing light.

(ii) A vessel being towed alongside shall exhibit a sternlight and at the forward end, sidelights and a special flashing light.

(iii) When vessels are towed alongside on both sides of the towing vessel, a sternlight shall be exhibited on the stern of the outboard vessel on each side of the towing vessel, and a single set of sidelights as far forward and as far outboard as is practicable, and a single special flashing light. Vessel being pushed ahead, not being part of a composite unit. Inland only. Vessel being towed alongside. Inland only.

(g) An inconspicuous, partly submerged vessel or object, or combination of such vessels or objects being towed, shall exhibit:

(i) If it is less than 25 meters in breadth, one all-round white light at or near each end;

(ii) If it is 25 meters or more in breadth, four all-round white lights to mark its length and breadth;

(iii) If it exceeds 100 meters in length, additional all-round white lights between the lights prescribed in paragraphs (g)(i) and (ii) of this Rule so that the distance between the lights shall not exceed 100 meters: provided, that any vessels or objects being towed alongside each other shall be lighted as one vessel or object;

(iv) A diamond shape at or near the aftermost extremity of the last vessel or object being towed; and

(v) The towing vessel may direct a searchlight in the direction of the tow to indicate its presence to an approaching vessel.

(i) Where from any sufficient cause it is impracticable for a vessel not normally engaged in towing operations to display the lights prescribed by paragraph (a), (c) or (j) of this Rule, such vessel shall not be required to exhibit those lights when engaged in towing another vessel in distress or otherwise in need of assistance. All possible measures shall be taken to indicate the nature of the relationship between the towing vessel and the vessel being assisted. The searchlight authorized by Rule 36 (§ 83.36) may be used to illuminate the tow.

(j) Notwithstanding paragraph (c) of this Rule, on the Western Rivers (except below the Huey P. Long Bridge at mile 106.1 Above Head of Passes on the Mississippi River) and on waters specified by the Secretary ‡, a power-driven vessel when pushing ahead or towing alongside, except as paragraph (b) of this Rule applies, shall exhibit:

(i) Sidelights; and

(ii) Two towing lights in a vertical line Power-driven vessel pushing ahead on Western River

(above the Huey P. Long Bridge at mile 106.1 Above Head of Passes on the Mississippi River). ‡ See 33 CFR 89.25, provided for reference on page 145 of this handbook.

Sections it refers to

The plain-English explanation on this page was written with AI from the regulation text above and checked automatically before publishing: every quote appears in the text, every number comes from it, and a second model confirmed each statement adds nothing the text doesn't say. Regulation text current as of August 12, 2024. The regulation text governs. RegKnot is not affiliated with the U.S. Coast Guard.