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SBF Sea · Lights & shapes · Question 91

Which vessel shows these lights?

  1. A power-driven vessel underway of less than 50 m in length.
  2. A power-driven vessel underway of 50 m or more in length.
  3. A vessel not under command, underway.
  4. A vessel restricted in her ability to manoeuvre, making way through the water, of 50 m or more in length.
In short

One white masthead light plus sidelights and a sternlight: that is a power-driven vessel underway. Because only one masthead light is lit, it is shorter than 50 m.

Your view · 40°
White above green: you see the starboard side. A single masthead light: shorter than 50 m.

In detail

Tap a waypoint to dive deeper.

b
Power-driven vessel of 50 m or moreFrom 50 m, a second masthead light is mandatory, abaft of and higher than the forward one. Only one is lit here.
c
Not under command, underwayA vessel not under command shows two red all-round lights in a vertical line and no masthead light. Sidelights and sternlight are only added when making way through the water.
d
Restricted in ability to manoeuvre, 50 m or moreA vessel restricted in her ability to manoeuvre shows red-white-red all-round lights in a vertical line. Making way at 50 m or more, she would also show two masthead lights.

Sidelights and sternlight together cover exactly one full circle. The masthead light overlaps the sidelights and shows ahead. Turn the figure: from behind you only see the sternlight.

225°
Masthead light, whiteFrom right ahead to 22.5° abaft the beam, on either side.
112.5°
Sidelights, red and greenRed to port, green to starboard. Each from right ahead to 22.5° abaft the beam.
135°
Sternlight, whiteAstern, 67.5° to either side.

Large ships show two masthead lights: one forward, a second one abaft of and higher than it. The line between the two tells you the ship’s heading. If they are exactly one above the other, she is heading straight for you.

A power-driven vessel under 12 m may show one white all-round light instead of masthead light and sternlight, plus the sidelights. You see this on many motorboats.

KVR Regel 23