Lights & Shapes Flashcards

What light(s) does a vessel of less than 50m show when at anchor?

Answer: One all-round white light

A vessel under 50m at anchor shows a single all-round white light in the fore part of the vessel where it can best be seen.

At what minimum range must the masthead light of a vessel of 50m or more be visible?

Answer: 6 miles

COLREGS Rule 22 requires the masthead light of a vessel 50m or more in length to be visible at a minimum range of 6 nautical miles.

A vessel engaged in trawling at night, when making way, shows which combination of lights?

Answer: Green over white all-round lights, sidelights and sternlight

A trawler underway and making way shows two all-round lights (green over white), plus sidelights and a sternlight.

What day signal does a vessel engaged in diving operations display?

Answer: A rigid replica of the International Code flag Alpha

A vessel with a diver down displays a rigid replica of Code flag Alpha (blue and white swallowtail), the international signal meaning 'I have a diver down — keep clear at slow speed'.

What additional all-round light does an air-cushion vessel (hovercraft) in non-displacement mode show?

Answer: A flashing yellow all-round light

An air-cushion vessel in non-displacement mode shows a flashing yellow all-round light in addition to the lights required for a power-driven vessel.

What arc of visibility does each sidelight cover?

Answer: 112.5°

Each sidelight covers 112.5°, from dead ahead to 22.5° abaft the beam on its respective side of the vessel.

When the length of the tow exceeds 200m, how many masthead lights does the towing vessel display?

Answer: Three masthead lights in a vertical line

When the tow exceeds 200m, the towing vessel must show three masthead lights in a vertical line instead of the usual two.