International Regulations For Preventing Collisions at Sea - Part C - Lights and Shapes

Lights and Shapes

20. Application

Rules concerning lights apply from sunset to sunrise, in conditions of restricted visibility, and in all other circumstances when it is deemed necessary. Rules concerning shapes apply during the day.

21. Definitions

"Masthead light" means a white light on the centreline of the vessel showing from right ahead to 22.5 degrees abaft the beam on either side of the vessel.

"Sidelights" means a green light on the starboard side and a red light on the port side each showing from right ahead to 22.5 degrees abaft the beam on its respective side. If the vessel is less than 20 metres (66 ft) long, the sidelights may be combined in one fixture carried on the centreline of the vessel.

"Sternlight" means a white light placed as nearly as practicable at the stern showing 67.5 degrees from right aft on each side of the vessel.

"Towing light" means a yellow light having the same characteristics as a "sternlight" defined above.

"All-round light" means a light visible from 360 degrees of the horizon.

"Flashing light" means a light flashing faster than 120 flashes per minute.

22. Visibility of lights

Lights must be bright enough to be visible as follows

23. Lights displayed by power-driven vessels underway

• A power-driven vessel underway must display:
  • a masthead light forward;
  • If over 50 metres (164 ft) length, then also a second masthead light aft and higher than the forward one; except that a vessel of less than 50 metres in length shall not be obliged to exhibit such light but may do so;
  • sidelights;
  • a sternlight.
• A hovercraft must also display an all-round flashing yellow light.
• A wing-in-ground craft must also display a bright all-round flashing red light when taking off, landing, or flying near the surface.
• A power-driven vessel of less than 12 metres (39.4 ft) may display only an all-round white light and sidelights. However, in the case of a skiff a wooden clinker rowing boat which falls into this category only needs to be capable of showing a white light.
• A power-driven vessel of less than 7 metres (23.0 ft) whose maximum speed does not exceed 7 knots (13 km/h; 8 mph) must be capable of showing a white light

24. Lights for vessels towing and pushing

• A power driven vessel when towing must show
  • two masthead lights on top of each other, instead of the masthead(s) prescribed in Rule 23;
  • sidelights;
  • a sternlight;
  • a towing light vertically above the sternlight;
  • a diamond shape if the tow is longer than 200 metres (656 ft).
• if a pushing vessel and the vessel it is pushing are rigidly connected, they count together as a power driven vessel and must show the light prescribed by Rule 23.
• If the pushing vessel and vessel being pushed are not rigidly connected, they must instead show:
  • two masthead lights on top of each other, instead of the masthead(s) prescribed in Rule 23;
  • sidelights;
  • a sternlight on the pushing vessel only.
• Power driven vessels larger than 50 metres (164 ft) which are towing or pushing and are not part of a composite unit must also show:
  • a second masthead abaft of and higher than the forward one (vessels smaller than 50 metres may also show this light).
• Vessels being towed that are not inconspicuous or partly submerged must show:
  • sidelights;
  • a sternlight;
  • a diamond shape if the tow is longer than 200 metres (656 ft).
• Any number of vessels being towed or pushed together shall be lit as one vessel, and
  • a vessel being pushed ahead must show sidelights at its forward end if it is not part of a composite unit;
  • a vessel being towed alongside must show a sternlight and sidelights at its forward end.
• A vessel being towed that are inconspicuous or partly submerged must show:
  • if it is narrower than 25 metres (82 ft), one all-round white light near the forward end (except if it is a dracone) and one near the after end;
  • if it is wider than 25 metres (82 ft), then also two all round white lights at the extremities of its breadth;
  • if it is longer than 100 metres (328 ft), then in a series of such all round white lights spaced no further than 100 metres (328 ft) apart;
  • a diamond shape near the end of the last vessel, and, if the tow is longer than 200 metres (656 ft), another diamond shape as far forward as possible.
  • If for any reason it is not possible to light the vessel according to these rules, all possible measures must be taken to light the vessel and indicate its presence.
  • If the towing vessel is not normally engaged in towing operations and it is impractical to light it correctly, it is not obliged to show these lights if it is towing a vessel in distress or in need of assistance. All possible measures must be taken to show that it is towing; in particular the towline should be illuminated.

25. Lights for sailing and rowing vessels

Sailing vessels underway and vessels under oars

(a) A sailing vessel underway shall exhibit:

1. sidelights;

2. a sternlight.

(b) In a sailing vessel of less than 20 metres (66 ft) in length the lights prescribed in paragraph (a) of this Rule may be combined in one lantern carried at or near the top of the mast where it can best be seen.

(c) A sailing vessel underway may, in addition to the lights prescribed in paragraph (a) of this Rule, exhibit at or near the top of the mast, where they can best be seen, two all-round lights in a vertical line, the upper being red and the lower green, but these lights shall not be exhibited in conjunction with the combined lantern permitted by paragraph (b) of this Rule.

(d) 1. A sailing vessel of less than 7 metres (23.0 ft) in length shall, if practicable, exhibit the lights prescribed in paragraph (a) or (b) of this Rule, but if she does not, she shall have ready at hand an electric torch or lighted lantern showing a white light which shall be exhibited in sufficient time to prevent collision.

2. A vessel under oars may exhibit the lights prescribed in this Rule for sailing vessels, but if she does not, she shall have ready at hand an electric torch or lighted lantern showing a white light which shall be exhibited in sufficient time to prevent collision.

(e) A vessel proceeding under sail when also being propelled by machinery shall exhibit forward where it can best be seen a conical shape, apex downwards.

26. Lights for fishing vessels

Fishing Vessels

(a) A vessel engaged in fishing, whether underway or at anchor, shall exhibit only the lights and shapes prescribed in this Rule.

(b) A vessel when engaged in trawling, by which is meant the dragging through the water of a dredge net or other apparatus used as a fishing appliance, shall exhibit:

1. two all-round lights in a vertical line, the upper being green and the lower white, or a shape consisting of two cones with their apexes together in a vertical line one above the other;

2. a masthead light abaft of and higher than the all-round green light; a vessel of less than 50 metres (164 ft) in length shall not be obliged to exhibit such a light but may do so;

3. when making way through the water, in addition to the lights prescribed in this paragraph, sidelights and a sternlight.

(c) A vessel engaged in fishing, other than trawling, shall exhibit:

1. two all-round lights in a vertical line, the upper being red and the lower white, or a shape consisting of two cones with apexes together in a vertical line one above the other;

2. when there is outlying gear extending more than 150 metres horizontally from the vessel, an all-round white light or a cone apex upwards in the direction of the gear;

3. when making way through the water, in addition to the lights prescribed in this paragraph, sidelights and a sternlight.

(d) The additional signals described in Annex II to these Regulations apply to a vessel engaged in fishing in close proximity to other vessels engaged in fishing.

(e) A vessel when not engaged in fishing shall not exhibit the lights or shapes prescribed in this Rule, but only those prescribed for a vessel of her length.

27. Lights for vessels not under command or restricted in their ability to manoeuvre

Vessels not under command or restricted in their ability to manoeuvre

(a) A vessel not under command shall exhibit:

1. two all-round red lights in a vertical line where they can best be seen;

2. two balls or similar shapes in a vertical line where they can best be seen;

3. when making way through the water, in addition to the lights prescribed in this paragraph, sidelights and a sternlight.

(b) A vessel restricted in her ability to manoeuvre, except a vessel engaged in mine-clearance operations, shall exhibit:

1. three all-round lights in a vertical line where they can best be seen. The highest and lowest of these lights shall be red and the middle light shall be white;

2. three shapes in a vertical line where they can best be seen. The highest and lowest of these shapes shall be balls and the middle one a diamond;

3. when making way through the water, a masthead light or lights, sidelights and a sternlight, in addition to the lights prescribed in sub-paragraph (i);

4. when at anchor, in addition to the lights or shapes prescribed in sub-paragraphs (i) and (ii), the light, lights or shape prescribed in Rule 30.

(c) A power-driven vessel engaged in a towing operation such as severely restricts the towing vessel and her tow in their ability to deviate from their course shall, in addition to the lights or shapes prescribed in Rule 24(a), exhibit the lights or shapes prescribed in sub-paragraphs (b)(i) and (ii) of this Rule.

(d) A vessel engaged in dredging or underwater operations, when restricted in her ability to manoeuvre, shall exhibit the lights and shapes prescribed in sub-paragraphs (b)(i), (ii) and (iii) of this Rule and shall in addition, when an obstruction exists, exhibit:

1. two all-round red lights or two balls in a vertical line to indicate the side on which the obstruction exists;

2. two all-round green lights or two diamonds in a vertical line to indicate the side on which another vessel may pass;

3. when at anchor, the lights or shapes prescribed in this paragraph instead of the lights or shape prescribed in Rule 30.

(e) Whenever the size of a vessel engaged in diving operations makes it impracticable to exhibit all lights and shapes prescribed in paragraph (d) of this Rule, the following shall be exhibited:

1. three all-round lights in a vertical line where they can best be seen. The highest and lowest of these lights shall be red and the middle light shall be white;

2. a rigid replica of the International Code flag "A" not less than 1 metre (3.3 ft) in height. Measures shall be taken to ensure its all-round visibility.

(f) A vessel engaged in mine clearance operations shall in addition to the lights prescribed for a power-driven vessel in Rule 23 or to the lights or shape prescribed for a vessel at anchor in Rule 30 as appropriate, exhibit three all-round green lights or three balls. One of these lights or shapes shall be exhibited near the foremast head and one at each end of the fore yard. These lights or shapes indicate that it is dangerous for another vessel to approach within 1,000 metres (0.62 mi) of the mine clearance vessel.

(g) Vessels of less than 12 metres (39.4 ft) in length, except those engaged in diving operations, shall not be required to exhibit the lights and shapes prescribed in this Rule.

(h) The signals prescribed in this Rule are not signals of vessels in distress and requiring assistance. Such signals are contained in Annex IV to these Regulations.

28. Lights for vessels constrained by their draught

A vessel constrained by her draft may, in addition to the lights prescribed for power-driven vessels in Rule 23, exhibit where they can best be seen three all-round red lights in a vertical line, or a cylinder.

29. Lights for pilot vessels

(a) A vessel engaged on pilotage duty shall exhibit:

• (i) at or near the masthead, two all-round lights in a vertical line, the upper being white and the lower red;
• (ii) when underway, in addition, sidelights and a sternlight;
• (iii) when at anchor, in addition to the lights prescribed in subparagraph (i), the light, lights, or shape prescribed in Rule 30 for vessels at anchor.

(b) A pilot vessel when not engaged on pilotage duty shall exhibit the lights or shapes prescribed for a similar vessel of her length.

30. Lights for vessels anchored and aground

• A vessel at anchor must display an all-round white light or one black ball in the fore part and another all-round white light at or near the stern at a lower level than the light in the fore part. BUT if the vessel is less than 50 meters in length it may exhibit an all-round white light where it can best be seen instead of the lights foresaid.

31. Lights for seaplanes