On small craft, it is up to the skipper and crew to determine the watch schedule. In the world of small cruising sailboats, I would consider both single-handed and double-handed vessels as being under-handed, because each crew member must take multiple watches during normal sleeping hours, resulting in a constant state of mild sleep deprivation. I would also consider cruising boats consisting of family units with small children to be under-handed, because in addition to the normal boat-keeping tasks, the adults on board have child rearing duties. Once children become teens and can take a watch themselves, they become---in addition to being beloved members of the family---assets as additional crew members.
Patrick and I are a double-handed (and therefore, under-handed) crew. I knew that the watch schedule we had used while coastal cruising (three hour watches) would not work in the long term for an offshore passage. When coastal cruising, our longest passage only spanned three nights. While we traded three hour watches during the night, both of us stayed up during the day, grabbing at most an hour's late afternoon nap on a cockpit bench. Afterwards, we would stop for a night or two at an anchorage or a dock and collapse into an exhausted heap, catching up on the sleep we had missed. Over the long term, this kind of schedule can lead to cranky temperment and poor judgment due to sleep deprivation. I started in early asking Patrick to agree to a watch schedule. Due to my lesser amount of experience, a four hour watch schedule didn't seem practical for us, because it seemed inevitable that I would always be disturbing Patrick's sleep. What we have settled into---and what seems to be working well---is a variable watch schedule. We each take a long, four-hour watch in the middle of the night (while the off-watch person sleeps), and we each have a shorter watch at each end. I usually take a short two or three hour watch after dinner from seven or eight until ten p.m., while Patrick naps. Then, Patrick takes a watch from 10:00-2:00 a.m. He usually checks in to the Pacific Seafarer's Net roll call over the radio during this watch. I'm on watch again from 2:00 a.m. until 6:00 a.m., followed by a nap from 6:00 until 8:00 or 9:00 a.m., while Patrick takes watch.
Of course, this watch schedule only works if nothing happens to interrupt it. If one of us has to get the other up for assistance during a crew member's normal sleep time, the schedule gets off, and we end up sleep deprived. Going without sleep is part and parcel of the sea life. We go with the flow, do what needs to be done, and eventually---with the sleep cycle as well as in all things---balance is restored.
During the day, we have no set watch schedule. We flexibly trade off watches with chores down below. If Patrick is downloading weather files or checking the engine, I keep watch above. If I'm cooking a meal, Patrick looks after the helm. We each usually take one additional "cat nap" at some point during the day, and the non-napping crew member is on watch.
This particular rhythm works for us, on this passage, at this point in time. Other crews have developed their own rhythms, but all we share the commonality of observing the maritime practice of watch-keeping.
Posted via Ham Radio at sea.