Monthly Archives: July 2018

Where should a vessel’s masthead lights be placed?

Power Driven vessel end on

Navsregs>COLREGS>Masthead light position

More delving into the detail of navigation lights, this time its the positioning of masthead lights.

The vertical positioning of Masthead lights

What part of the COLREGs covers the vertical positioning of Masthead lights?

Annex 1 part 2.

At what height should masthead lights be carried?

On a power-driven vessel of 20 meters or more in length:

The forward masthead light, or if only one masthead light is carried, then that light is:

  • At a height above the hull of not less than 6 meters


  •  If the breadth of the vessel exceeds 6 meters, then at a height above the hull not less than such breadth, so however that the light need not be placed at a greater height above the hull than 12 meters

The masthead light of a power-driven vessel of 12 meters but less than 20 meters in length:

  •  Shall be placed at a height above the gunwale of not less than 2.5 meters.

The masthead light of a power-driven vessel of less than 12 meters in length:

  • These may carry the uppermost light at a height of less than 2.5 meters above the gunwale.
  • When however a masthead light is carried in addition to side-lights and a sternlight or the all-round light prescribed in Rule 23(c)(i) is carried in addition to sidelights, then such masthead light or all-round light shall be carried at least 1 meter higher than the

The masthead light or lights prescribed in shall be so placed as to be above and clear of all other lights and obstructions except for Not Under Command Lights and Restricted in Manoeuvrability.


What is the separation of two masthead lights?

The after one shall be at least 4.5 meters vertically higher than the forward one.

The vertical separation of masthead lights of power-driven vessels shall be such that in all normal conditions of trim the after light will be seen over and separate from the forward light at a distance of 1000 meters from the stem when viewed from sea level.

Horizontal positioning of Masthead lights

What part of the COREGS covers the horizontal positioning of Navigation lights?

Annex 1 3 Horizontal positioning and spacing of lights

the horizontal distance between them shall not be less than one half of the length of the vessel but need not be more than 100 meters. The forward light shall be placed not more than one quarter of the length of the vessel from the stem.

A quick summary of the Masthead Light distances


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