the.com/watchkeeping

means The maritime practice of standing timed shifts (watches) to keep a vessel, its crew, and its course continuously monitored, day and night.

from From 'watch,' rooted in Old English 'wæcce' (a state of being awake, a vigil), joined to 'keeping' in the sense of maintaining or tending something over time. Ships have always needed eyes open around the clock, so crews were divided into shifts called watches — a system old enough to predate reliable clocks, when sailors judged time by sandglasses turned every half hour. 'Watchkeeping' names the whole discipline: the handovers, the logs, the vigilance passed from one set of eyes to the next so the ship is never, even for a moment, unwatched.