Watchkeeping arrangements

Watchkeeping arrangements are the schedules and manning that staff the navigational and engine-room watches in line with STCW Chapter VIII. The deep-sea standard is the three-watch system: each officer keeps two four-hour watches a day (4-on-8-off), the master normally supernumerary to the rota. Coastal and pilotage work may shift to a two-watch (6-on-6-off) regime, which STCW A-VIII/1 constrains through the rest-hours floor of 10 hours in any 24 and 77 in any seven days, split into no more than two periods, one of at least six hours. The dog watches split the 1600 to 2000 block in two so the rota rotates and no officer permanently stands the middle watch.