Lights & Shapes Flashcards

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

Answer: Masthead light, sidelights and sternlight

A power-driven vessel under 50m requires one forward masthead light (225°), red and green sidelights (112.5° each), and a white sternlight (135°).

What is the arc of visibility of a vessel's sternlight?

Answer: 135°

The sternlight shines from 67.5° either side of dead astern, giving a total arc of 135°.

What day shape must a vessel at anchor display?

Answer: A black ball

A vessel at anchor must hoist a black ball shape in the forepart of the vessel where it can best be seen.

A sailing vessel proceeding under sail and engine simultaneously must display what day shape?

Answer: A cone, point downwards

A sailing vessel using its engine must display a cone, apex downwards, in the fore part of the vessel, indicating it is not purely under sail.

Which vessels display two all-round red lights in a vertical line at night?

Answer: Vessel not under command

A vessel not under command shows two all-round red lights vertically, indicating it cannot manoeuvre due to exceptional circumstances and cannot keep out of the way.

What lights must a vessel restricted in her ability to manoeuvre show (in addition to steaming lights)?

Answer: Three all-round lights: red, white, red

A vessel restricted in ability to manoeuvre shows three all-round lights vertically (red, white, red top to bottom), in addition to normal steaming and sidelights when making way.

A vessel aground at night shows what additional lights beyond her anchor lights?

Answer: Two all-round red lights in a vertical line

A vessel aground shows her normal anchor lights plus two additional all-round red lights displayed in a vertical line.