The night boat that carries the sun god Ra through the underworld is the Mesektet.
In Egyptian solar mythology, Ra traveled across the sky during the day in the Mandjet, often called the Boat of Millions of Years. At sunset, the solar vessel passed through the western horizon and entered the Duat, the underworld. There, Ra continued his journey aboard the Mesektet during the twelve hours of night.
The nightly voyage was not peaceful. Ra had to pass through regions and gates guarded by supernatural beings while facing Apophis, the enormous serpent associated with chaos. Each dawn, Ra emerged renewed, explaining the daily return of sunlight and the cycle of death and rebirth.
A common mix-up is choosing Mandjet: it is the daytime boat, whereas Mesektet is the nighttime vessel. “Barque of the Sun” is a broad descriptive phrase, not the specific name asked for. Egyptian texts and later summaries may vary in transliteration, but Mesektet is the standard English form for this quiz answer.