Lights & Shapes Flashcards

What lights must a power-driven vessel of 50m or more show when underway at night?

Answer: Two masthead lights, sidelights and sternlight

A power-driven vessel of 50m or more must display two masthead lights (the forward one placed higher), together with sidelights and a sternlight.

What lights does a pilot vessel on duty display when underway?

Answer: White over red all-round lights, sidelights and sternlight

A pilot vessel on duty shows two all-round lights vertically (white over red), plus sidelights and sternlight when underway.

What is the minimum lighting requirement for a vessel under 7m making no more than 7 knots?

Answer: An all-round white light, with sidelights if practicable

Under COLREGS Rule 23, a vessel under 7m making no more than 7 knots need only show an all-round white light, though sidelights should also be shown if practicable.

What day shape does a vessel constrained by her draught display?

Answer: A black cylinder

A vessel constrained by her draught displays a black cylinder as a day shape, warning other mariners of her very limited ability to deviate from her course.

A sailing vessel of less than 20m may display what alternative to separate sidelights and sternlight?

Answer: A tricolour lantern at or near the top of the mast

A sailing vessel under 20m may use a tricolour lantern (combining red, green, and white sectors) at or near the top of the mast in place of separate sidelights and sternlight.

When a tow exceeds 200m, what day shape is displayed by the vessels involved?

Answer: A diamond shape, displayed by both the towing vessel and the vessel being towed

When the length of the tow exceeds 200m, both the towing vessel and the vessel being towed display a diamond shape where it can best be seen.

At what minimum range must the sidelights of a vessel between 12m and 50m be visible?

Answer: 2 miles

COLREGS Rule 22 requires sidelights on a vessel between 12m and 50m to be visible at a minimum range of 2 nautical miles.