In the navy, the
time on board a
ship is divided into several
shifts, or watches. Each watch is subdivided into half-hour segments called bells; at eight
bells, the watch is over.
- Noon to 4:00 p.m. - Afternoon watch
- 4:00 p.m. to 6:00 p.m. - First dogwatch
- 6:00 p.m. to 8:00 p.m. - Second dogwatch
- 8:00 p.m. to midnight - 1st night watch
- Midnight to 4:00 a.m. - Middle watch or mid watch
- 4:00 to 8:00 a.m. - Morning watch
- 8:00 a.m. to noon - Forenoon watch
If the crew is divided into three watches, then each watch gets 4 hours on and 8 hours off; everyone gets a reasonable amount of sleep. With two watches, 4 hours on and 4 hours off means that at any time, half the crew is on duty - it is more stressful for everyone.