Watch arrangements, lookout and fitness for duty
1The lesson in plain words
The master sets a watch that can always keep a proper lookout. The OOW may be sole lookout only by day, after a careful check, with help on call.
Composition of the watch
The master sets the bridge team and reviews it as conditions change. Consider visibility, weather and daylight; traffic and dangers; extra navigation, radio or machinery-alarm duties; automatic steering; radar, the electronic chart display and information system (ECDIS) and other aids; and each watchkeeper's fitness and experience. Never leave the bridge unattended. As OOW, remain on the bridge until another qualified OOW properly relieves you. A lookout alone cannot relieve you.
The lookout
A proper lookout, as COLREG Rule 5 requires, is kept by sight, hearing and all available means, and no other duty may interfere with it. The helmsperson is not the lookout while steering. The exception is a small ship with an unobstructed all-round view from the helm, unimpaired night vision and no other lookout impediment. How a lookout reports is covered in Lookout duties.
Sole lookout by day
The OOW may be the sole lookout in daylight, but on each occasion only if: the situation has been carefully assessed and it is established without doubt that it is safe; weather, visibility, traffic, nearby dangers and traffic separation schemes have all been taken into account; and assistance can be summoned to the bridge at once. At night, in poor visibility or in heavy traffic, post a separate lookout. Company rules may be stricter.
Rest and fitness
STCW A-VIII/1 gives every watchkeeper at least 10 hours of rest in any 24 hours and 77 hours in any 7 days. Daily rest may be split into no more than two periods, one at least 6 hours long, with no more than 14 hours between them. Record rest hours. The STCW ceiling is 0.05 % blood alcohol or 0.25 mg/l in breath; stricter limits may apply. In an emergency the master may suspend the schedule; afterwards, those who worked through rest get adequate rest.
The watch alarm
The bridge navigational watch alarm system (BNWAS) monitors bridge activity. SOLAS V/19 requires it on cargo ships of at least 150 GT and all passenger ships, operating under way at sea. After 3–12 minutes without a reset: a visual alarm on the bridge; 15 seconds later, a bridge audible alarm; 15 seconds later, master/back-up officer alarm; after another 90 seconds unanswered, further crew (up to 3 minutes on larger ships). On ships other than passenger ships, the remote stages may sound in all locations at once. Never bypass the reset.
2Key data
- Minimum rest
- 10 h in any 24 h and 77 h in any 7 days (STCW A-VIII/1)
- Splitting daily rest
- Max 2 periods, one at least 6 h; at most 14 h between them
- STCW alcohol ceiling
- 0.05 % blood alcohol or 0.25 mg/l breath; stricter limits may apply
- BNWAS carriage
- Cargo ships of 150 GT or more; all passenger ships (SOLAS V/19)
- BNWAS sequence
- 3–12 min; light → bridge alarm → back-up/master → further crew
3Key points
- 1
The bridge is never left unattended.
- 2
The OOW may be sole lookout only in daylight, after a careful check, with help on call at once.
- 3
Helmsperson as lookout: small ship, unobstructed all-round view at the helm, unimpaired night vision, no other lookout impediment.
- 4
Daily rest: 10 h, split into at most two periods, one at least 6 h. Weekly rest: 77 h in any 7 days.
- 5
The BNWAS stays on whenever the ship is under way at sea.
4Frequent mistakes
Wrong: On a small ship the OOW can be the lookout at night if the radar is working.
Right: The sole-lookout allowance is for daylight only. At night, post a lookout and use the radar as well.
Wrong: Rest hours are a paperwork issue; you can catch up at the next port.
Right: The minimums apply in any 24 hours and any 7 days. A tired OOW is a navigational hazard; tell the master before the watch.
Wrong: The BNWAS can be switched off on a calm coastal passage.
Right: SOLAS requires it to be in operation whenever the ship is under way at sea.
5Practice case & exam keys
You are mate on a 420 GT coaster where you and the master stand 6 hours on, 6 hours off. After your night watch you supervised cargo all morning. Sailing is at 1200 and your watch starts then, but you have had only 5 hours of rest in the last 24.
Show the answer
You are below the STCW minimum of 10 hours in any 24, and fatigue makes you a hazard on the bridge. Tell the master before sailing. The master must rearrange the watch: delay sailing, take the watch with you resting first, or bring in another qualified officer. Record the hours honestly; the record shows where the schedule needs to change.
Exam keys
- Sole lookout: daylight only, careful assessment, assistance immediately available.
- Daily rest: 10 h/24 h, two periods max, one at least 6 h, 14 h max between. Weekly: 77 h/7 days.
- BNWAS: cargo ships of 150 GT or more and all passenger ships, on whenever under way at sea.
Finish this unit
When you've read it, match the terms, then answer three questions. Get them all right to finish the unit; opening the page alone doesn't count.
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