Seamanship I Test 1 Practice Test

When a vessel is at anchor, it must show a white light that is visible all around the vessel (360 degrees). This white all-round light, often called the anchor light, clearly signals to other ships that the vessel is not underway and is stationary.

The other signals don’t indicate anchoring: red port and green starboard lights show a vessel under way and its direction of travel; a white stern light alone isn’t the standard signal for being anchored (it implies movement and direction from the stern). A flashing yellow light is used for special situations or caution, not for anchoring.

So the white all-round light is the correct indication of a vessel anchored at night.