Bridge watchkeeping and bridge resource management

In short

Bridge watchkeeping is the continuous, legally defined duty of navigating a ship safely on behalf of the Master, governed by STCW 1978 as amended (Chapter VIII and Code Part A-VIII/2), SOLAS Chapter V and COLREG Rules 5 and 8. Bridge Resource Management (BRM, or Bridge Team Management) is the human-element discipline layered on top of it: using all people, equipment and information on the bridge as one team so that a single person's error does not become a casualty. Investigations consistently attribute roughly four out of five collisions and groundings to human factors - poor lookout, unchallenged assumptions, fatigue and broken communication - not to equipment failure. In India it is examined in B.Sc Nautical Science (Watchkeeping and Seamanship, Navigation), in the DG of Maritime Administration (formerly DG Shipping) written and oral examinations for Second Mate, Mate and Master Foreign-Going at the MMDs, and in the mandatory DGS-approved BRM/BTM, ARPA and ECDIS simulator courses. Fleet interviews at SCI, Great Eastern Shipping, Anglo-Eastern, Fleet Management, Synergy, MSC and Maersk crewing offices test it before every joining.

Explained

Legal framework and the watch system

• STCW Convention and Code, Chapter VIII - "Standards regarding watchkeeping": fitness for duty (rest hours), watch arrangements, principles for keeping a navigational watch. Part A is mandatory, Part B is guidance.
• SOLAS Chapter V (Safety of Navigation): Reg. 22 bridge visibility, Reg. 19 carriage of navigational equipment (radar, ECDIS, AIS, BNWAS, gyro, echo sounder), Reg. 27 charts and publications corrected and up to date, Reg. 34 safe navigation and voyage planning.
• COLREG Rule 5 (proper look-out by sight and hearing and by all available means) and Rule 8 (action to avoid collision) are the collision-avoidance duties of the watch; the manoeuvring rules themselves belong to the COLREGs topic.
• India: the Merchant Shipping Act, 2025 (in force 15 March 2026, replacing the former Merchant Shipping Act, 1958) and the M.S. (STCW) Rules give effect to STCW; certification, manning scales, DGS orders, M.S. notices and training-course approval come from the Directorate General of Maritime Administration (the former DG Shipping). Indian Maritime University and DGS-approved institutes run the pre-sea and simulator courses.
• Watch pattern: the traditional 4-on/8-off three-watch system - Chief Officer 04-08 and 16-20, Second Officer 12-16 and 00-04, Third Officer 08-12 and 20-24. The Master keeps no watch but is on call at all times and takes the con in pilotage, restricted waters and emergencies.
• Composition of the watch depends on conditions: OOW alone; OOW + dedicated lookout; OOW + lookout + helmsman (hand steering); plus Master and/or pilot. Sole lookout by the OOW is permitted only in daylight, after a careful risk assessment (visibility, traffic, proximity of dangers, equipment working, immediate assistance obtainable) and must be ended at once if any doubt arises.
• The OOW is the Master's representative and is responsible for safe navigation and for complying with the COLREGs at all times; presence of the Master does not relieve the OOW until the Master has explicitly said "I have the con", and that transfer is logged.
• The pilot is an advisor. The Master-pilot exchange (MPX) covers the passage plan, speed, tugs, berthing side, draught, UKC and abort points. Master and OOW retain responsibility and must monitor the pilot's actions independently.

Keeping the watch: handover, routine and calling the Master

• Taking over a watch (A-VIII/2): do not take over if your vision is not yet adjusted to darkness or you are in any doubt about your fitness. Satisfy yourself personally about position, course, speed, draught, UKC, traffic, weather, tides, machinery status, standing and night orders, and any navigational warning.
• Never hand over while a manoeuvre to avoid collision is in progress - complete the action first, then relieve.
• Routine of the watch: fix the position by two independent methods at an interval suited to the waters (GNSS plus visual bearings, radar range-and-bearing, parallel index); compare gyro and magnetic compass at least once a watch and record the error; check the steering mode and that the autopilot/helm is responding; monitor cross-track error; test equipment and alarms; log weather, soundings and events.
• Call the Master immediately (A-VIII/2 para 49) if: restricted visibility is encountered or expected; traffic or movement of other ships causes concern; difficulty in maintaining course; failure to sight land, a navigation mark or soundings by the expected time; land or a mark is sighted or soundings change unexpectedly; machinery, steering gear or essential equipment fails; radio, navigation equipment or alarm failure; heavy weather and doubt about weather damage; ice, derelict or any hazard; any emergency, or any other situation of doubt. Calling the Master does not relieve the OOW, who must continue to take necessary action.
• Master's standing orders are permanent, ship-specific written instructions (CPA/TCPA limits, when to call, UKC policy, speed, use of hand steering, no sole lookout at night). Night orders / bridge order book are written each evening for that night and are signed by each OOW on taking over.
• Logbook and records: deck logbook, bearing book, compass error book, gyro/magnetic comparison, chart or ECDIS record. Entries are contemporaneous legal evidence; never backdate or erase - strike through, initial and re-enter.
• Changeover of steering mode from auto to hand must be tested regularly and done by a qualified helmsman before entering congested waters; test steering gear and bridge equipment before arrival and departure (SOLAS V/26 - within 12 hours before departure).

Passage planning and monitoring - berth to berth

• IMO Resolution A.893(21) and SOLAS V/34 require a plan berth to berth, including pilotage waters, approved by the Master and available to every OOW.
• Four stages: Appraisal (gather all charts, routeing guides, pilot books, tide tables, ALRS/ALL, weather, company and port information; assess risks) → Planning (lay the tracks, mark no-go areas, abort points, points of no return, wheel-over points, clearing bearings/ranges, parallel index lines, reporting points, margins of safety, contingency anchorages) → Execution (adjust for actual tide, traffic, ETA, daylight, manning) → Monitoring (fix, cross-check and confirm that the ship is following the plan).
• Parallel indexing (PI): a radar line drawn parallel to the intended track at the cross-track distance from a fixed radar-conspicuous object - gives continuous, instantaneous track-keeping without plotting a fix.
• Margins of safety and no-go areas are drawn from the deepest draught plus required UKC, squat and tidal height, not from the charted depth alone. CATZOC (zone of confidence) on ENCs tells you how reliable the survey is.
• ECDIS watchkeeping: set safety depth and safety contour from the ship's draught and UKC policy, use the route check and guard zone, monitor at a proper scale (never navigate zoomed out, and heed the overscale indication that appears when the display is zoomed in beyond the cell's compilation scale), keep cells updated, and know the backup arrangement (second type-approved ECDIS or folio of paper charts). ECDIS is a watchkeeping tool, not the watch - look out of the window.
• Radar and ARPA: use long and short ranges alternately, know the blind and shadow sectors from masts and cargo, beware target swap, lost targets, trial manoeuvre being a simulation only, and AIS data being as good only as the other ship's input. Systematic observation and plotting of every target is required by COLREG Rule 7.
• BNWAS (Bridge Navigational Watch Alarm System, SOLAS V/19): stage 1 visual reminder, then bridge audible, then a call to the Master and backup officer - it monitors OOW alertness and must be in operation whenever the ship is under way. VDR/S-VDR records bridge audio, radar, conning and alarms - the "black box" used by investigators.
• Bridge visibility (SOLAS V/22): the view of the sea surface from the conning position must not be obscured by more than two ship lengths or 500 m, whichever is less, forward of the bow to 10° on either side; blind sectors are to be minimised and known; horizontal field of view at least 225°.

Bridge Resource Management - the human element

• Definition: the effective use of all available resources - people, equipment, information and time - to achieve a safe passage; a bridge team rather than a one-man band.
• Situational awareness (SA) has three levels: perception (what is happening), comprehension (what it means), projection (what will happen next). Loss of SA shows as fixation on one task, ambiguity, confusion, poor communication and departure from the plan.
• Error chain: casualties are almost never one mistake. Recognised error-chain indicators - ambiguity, distraction, inadequate communication, improper conning or lookout, violation of procedures, confusion, non-compliance with the passage plan, failure to monitor, inadequate handover - each one is a chance to break the chain. One link broken stops the accident.
• Authority gradient: too steep (the Master is never questioned) and errors go unchallenged; too flat and nobody decides. The remedy is an agreed challenge-and-response culture.
• Challenge and response / assertiveness: the junior's duty to speak up, escalating - "I have a concern… I am uncomfortable… this is unsafe, we must alter now" - and the Master's duty to acknowledge. Train it before you need it.
• Closed-loop communication: order → repeat-back → execution reported → acknowledged. Helm orders are always repeated back ("Port ten" - "Port ten, ten of port wheel on"); all internal bridge communication in a common working language, external in Standard Marine Communication Phrases (SMCP).
• Role allocation and cross-checking: when the Master or pilot has the con, the OOW navigates and monitors independently; the helmsman steers only; the lookout only looks out and reports. The "navigator" never becomes the "conning officer" at the same time in restricted waters.
• Workload management: plan tasks so that peaks are anticipated - pre-arrival paperwork done before the approach, not during it; use checklists (pre-arrival, pre-departure, pilot boarding, changeover of watch, restricted visibility, heavy weather) to offload memory.
• Automation issues: complacency and over-reliance, mode confusion (track control vs heading control vs hand steering), alarm flooding and the normalisation of silenced alarms.
• Short-handed and distraction risks: mobile phones, administrative work, VHF chat and ECDIS menu-diving are recognised contributors to groundings. Many Indian-managed fleets have a written bridge mobile-phone ban.

Fitness for duty: fatigue, rest hours and drugs and alcohol

• STCW A-VIII/1 minimum rest (as amended at Manila, 2010): at least 10 hours of rest in any 24-hour period and 77 hours in any 7-day period; the 10 hours may be split into no more than two periods, one of which must be at least 6 hours; the interval between consecutive rest periods must not exceed 14 hours.
• Exceptions by collective agreement are limited and recorded; musters, drills and emergency work override rest but compensatory rest must be given. Records of daily rest hours are maintained, signed by the seafarer and the Master, and are inspected by Port State Control and the Maritime Labour Convention, 2006 inspection regime (India has ratified MLC 2006).
• Alcohol limit (A-VIII/1): not more than 0.05% blood alcohol content (BAC) or 0.25 mg/l in breath, with a minimum 4-hour abstention before assuming a watch; most Indian and international fleets operate a stricter or zero-tolerance company policy - state the company limit, not just the STCW figure.
• Fatigue symptoms and countermeasures: micro-sleeps, slowed reaction, poor decisions, irritability; countered by rest-hour planning, napping, bright light, task rotation, not by caffeine alone. IMO's Guidelines on Fatigue (MSC.1/Circ.1598) is the reference document.

Special conditions of the watch

• Restricted visibility: inform the Master, post an extra lookout, sound fog signals, reduce to safe speed, switch to hand steering, use radar on appropriate ranges, close watertight doors, man the engine-room or confirm engines on standby, listen outside the wheelhouse. (Manoeuvring rules themselves are under COLREGs.)
• Coastal and pilotage waters: larger-scale charts, fixes at short intervals, Master on the bridge, double watch, VTS reporting (for example Mumbai, Kandla, Kochi and Chennai VTS), tugs and anchors ready.
• Heavy weather: course and speed to reduce slamming, parametric rolling and shipping water; secure the ship; synchronism and resonance avoided; weather routeing advice.
• Open ocean: longer fix intervals are acceptable, but GNSS must still be cross-checked against celestial or radar fixes and the gyro error monitored.
• Watch in port and at anchor: an anchor watch monitors position by bearings/ranges, a swinging circle and ECDIS anchor-watch alarm, weather and dragging; the detailed ground tackle and cable work belongs to the seamanship topic.
• Under-keel clearance is a watchkeeping decision at every stage: charted depth + height of tide − draught − squat − heel − wave allowance ≥ company minimum UKC (commonly 10% of draught, or a port-stated figure; always use the company/port value).

Key points

• OOW - the Master's representative, solely responsible for safe navigation and COLREG compliance until relieved or until the Master formally takes the con.
• STCW Chapter VIII / Code A-VIII/2 - the mandatory standard for watch arrangements and principles of a navigational watch.
• Rule 5 lookout - by sight AND hearing AND all available means; radar and AIS supplement, never replace, the human lookout.
• Sole lookout - daylight only, after risk assessment, discontinued the moment doubt arises; never at night.
• Handover rule - never hand over the watch during a collision-avoidance manoeuvre; relieving officer must personally verify position, traffic and orders.
• Calling the Master - restricted visibility, traffic concern, equipment failure, unexpected soundings or marks, heavy weather, ice, any doubt; calling does not relieve the OOW of action.
• Standing orders vs night orders - permanent ship policy vs orders written for that specific night, both signed.
• Passage plan - berth to berth, four stages: appraisal, planning, execution, monitoring; approved by the Master.
• Parallel index - radar line parallel to the track at the cross-track distance; continuous track monitoring.
• ECDIS settings - safety depth and safety contour from draught plus UKC; route check and guard zone on; correct scale; backup arrangement known.
• BNWAS (SOLAS V/19) - escalating alarm that detects OOW incapacity; must be active whenever under way.
• Bridge visibility (SOLAS V/22) - blind sector forward not more than 2 ship lengths or 500 m, whichever is less.
• Situational awareness - perception, comprehension, projection; loss shows as fixation, ambiguity and plan deviation.
• Error chain - accidents are a sequence; breaking any one link (speaking up, a cross-check, a challenge) prevents the casualty.
• Closed-loop communication - order, repeat-back, execution report, acknowledgement; SMCP for external traffic.
• Rest hours - 10 h in 24 (max two periods, one ≥ 6 h) and 77 h in 7 days; records signed and inspected.
• Alcohol - STCW limit 0.05% BAC / 0.25 mg/l breath, 4 hours' abstention before a watch; company policy may be zero.
• Indian regulator - Directorate General of Maritime Administration (formerly DG Shipping) under the Merchant Shipping Act, 2025; CoC examinations and oral at the MMDs.

Formulas and examples

Example 1 - ETA and the speed required. At 1400 the ship is 246 nm from the pilot station, making 14.5 kn; pilot is booked for 0600 next day.

• Time at present speed = 246 / 14.5 = 16.97 h = 16 h 58 min → ETA 0658, i.e. 58 minutes late.
• Time available 1400 → 0600 = 16 h. Required speed = 246 / 16 = 15.375 ≈ 15.4 kn.
• Watchkeeping action: enter the new RPM requirement in the night orders, inform the Master and engine room, and recheck the UKC at the new speed because squat rises with V².

Example 2 - Dipping range and radar horizon. Light charted at height 42 m; observer's eye height 18 m; radar scanner 24 m; target (a buoy with a 12 m topmark).

• Visual dipping range = 2.09 (√42 + √18) = 2.09 (6.481 + 4.243) = 2.09 × 10.724 = 22.4 nm.
• Radar detection range = 2.21 (√24 + √12) = 2.21 (4.899 + 3.464) = 2.21 × 8.363 = 18.5 nm.
• Use: if the light "rises" much earlier than 22.4 nm, the position or the identification is wrong - a classic prompt to call the Master (failure to sight / unexpected sighting).

Example 3 - Rate of turn and wheel-over point. Speed 12 kn, planned turning radius 0.5 nm, alteration of course 60°.

• ROT = 0.955 × 12 / 0.5 = 22.9 °/min (set this on the ROT indicator / track-control system).
• Wheel-over distance D = 0.5 × tan 30° = 0.5 × 0.5774 = 0.289 nm ≈ 535 m before the course-alteration point.
• Mark the WOP on the chart/ENC with a clearing bearing or radar range to a fixed object so the turn can be started without a fix.

Example 4 - Squat and under-keel clearance. Bulk carrier, C_b = 0.80, static draught 12.20 m, charted depth 14.0 m, height of tide +1.8 m, heel allowance 0.30 m, company minimum UKC = 10% of draught.

• Available depth = 14.0 + 1.8 = 15.80 m; static clearance = 15.80 − 12.20 = 3.60 m.
• At 10 kn in the confined channel: squat = 0.80 × 10² / 50 = 1.60 m → UKC = 3.60 − 1.60 − 0.30 = 1.70 m.
• Required UKC = 0.10 × 12.20 = 1.22 m → compliant, margin 0.48 m.
• At 13 kn: squat = 0.80 × 169 / 50 = 2.70 m → UKC = 3.60 − 2.70 − 0.30 = 0.60 m, which is below the required 1.22 m. Reducing to 8 kn gives squat = 0.80 × 64 / 50 = 1.02 m and UKC = 2.28 m. Squat is the reason "slow down in shallow water" is a watchkeeping rule, not a courtesy.

Example 5 - Rest-hour compliance. Third Officer: watches 0800-1200 and 2000-2400, plus deck work 1300-1500.

• Work in the 24 h from 0000 = 4 + 2 + 4 = 10 h; total rest = 14 h - the 10-hour minimum is met.
• But the rest falls in three periods: 0000-0800 (8 h), 1200-1300 (1 h) and 1500-2000 (5 h). STCW allows a maximum of two periods, so this schedule is non-compliant.
• Fix: move the deck work to 1200-1400, giving rest 0000-0800 (8 h) and 1400-2000 (6 h) - two periods, one of 8 h and one of 6 h, interval between them 6 h (< 14 h): compliant. Weekly check: 14 h × 7 = 98 h ≥ 77 h.

Where it is used

• Deck officer careers: Third/Second/Chief Officer and Master on tankers, bulk carriers, container ships, gas carriers and offshore vessels - with Indian and foreign managers such as SCI, Great Eastern Shipping, Essar Shipping, Anglo-Eastern, Fleet Management, Synergy, V.Group, MSC and Maersk.
• CoC examinations and training: DG of Maritime Administration written papers and MMD orals at Mumbai, Kolkata, Chennai and Kochi; DGS-approved simulator courses - BRM/BTM, ARPA, ECDIS, NWKO, RANSCO - at IMU campuses and private maritime institutes.
• Harbour and coastal operations: pilots at Indian major ports, VTS operators (Mumbai, Kandla, Paradip, Chennai), Coast Guard and Navy bridge teams, tug and dredger masters.
• Shore roles after sea time: marine superintendents and HSQE departments auditing bridge practice under the ISM Code, Port State Control and flag-state surveyors, P&I and hull-and-machinery surveyors, nautical faculty.
• Casualty investigation and insurance: VDR and ECDIS playback analysis for groundings and collisions, used by the Directorate of Marine Casualty Investigation, class societies and claims adjusters.
• Vetting inspections: SIRE 2.0 (tankers) and the DBMS/RightShip questionnaires examine passage plans, bridge checklists, rest-hour records, UKC calculations and standing orders directly.

Interview questions

• Q: Who is responsible for the safety of navigation when the Master is on the bridge? A: The OOW remains responsible until the Master formally announces that he has taken over the con, and that transfer must be recorded in the logbook.
• Q: When would you call the Master? A: Restricted visibility, traffic causing concern, difficulty holding course, failure to sight land or a mark when expected, unexpected soundings, equipment or steering failure, heavy weather, ice, any emergency - and in any case of doubt; I would keep acting on the situation while calling.
• Q: Can you be the sole lookout? A: Only in daylight, after assessing visibility, traffic, proximity of dangers, equipment status and the availability of immediate assistance - and I must call additional help the moment any doubt arises.
• Q: What are the four stages of passage planning? A: Appraisal, planning, execution and monitoring; the plan must be berth to berth, approved by the Master and available to every OOW.
• Q: What is parallel indexing and why use it? A: A radar line drawn parallel to the intended track at the cross-track distance from a conspicuous fixed object - it gives continuous track monitoring in pilotage waters without stopping to plot a fix.
• Q: How do you set the safety contour on an ECDIS? A: From the deepest draught plus squat and the company's required UKC, rounded up to the next available contour in the ENC; the safety depth is set similarly so spot soundings shallower than it are highlighted.
• Q: What is BNWAS and when must it be operating? A: The Bridge Navigational Watch Alarm System, required by SOLAS V/19; it gives a visual reminder, then a bridge alarm, then calls the Master and backup officer, and must be in operation whenever the ship is under way at sea.
• Q: What are the STCW rest-hour requirements? A: At least 10 hours in any 24 and 77 in any 7 days; the 10 hours in no more than two periods with one of at least 6 hours, and no more than 14 hours between consecutive rest periods.
• Q: Give three indicators of an error chain. A: Ambiguity or disagreement about the situation, departure from the passage plan without announcing it, and inadequate or one-way communication - others are distraction, improper lookout, confusion and procedural violation.
• Q: The pilot orders a course you believe will take the ship into shallow water. What do you do? A: Challenge immediately and explicitly - state the depth, the UKC and my concern to the Master and pilot, and if no satisfactory answer is given, the Master must act independently because the pilot is an advisor, not the responsible navigator.
• Q: Why slow down in shallow water? A: Squat increases roughly with the square of the speed, so reducing speed is the fastest way to recover under-keel clearance; it also reduces bank effect, loss of steering control and wash damage.
• Q: Difference between standing orders and night orders? A: Standing orders are the Master's permanent written policy for the ship; night orders are specific instructions written for that particular night's navigation, and both are read and signed by each OOW.

Common mistakes

• Treating GNSS and ECDIS position as the watch - no visual or radar cross-check, no compass error check, no look out of the window.
• Quoting the rest-hour totals (10 and 77) but forgetting the split rule (maximum two periods, one of at least 6 hours) and the 14-hour interval, which is where most schedules actually fail.
• Saying the Master's presence or a pilot on board relieves the OOW of responsibility; it does not until the con is formally handed over, and never in the pilot's case.
• Handing over the watch, or going below, in the middle of a collision-avoidance or anchoring manoeuvre.
• Calculating UKC from charted depth and draught alone, omitting squat, heel and swell allowance - and using the open-water squat formula in a confined channel (it roughly doubles).
• Confusing the dipping-range constant (2.09) with the radar-horizon constant (2.21), or forgetting to add the observer's eye height.
• Describing BRM as "being polite on the bridge" instead of the specific tools - closed-loop communication, challenge and response, role allocation, cross-checking and error-chain recognition.
• Forgetting the Indian regulatory update: the Merchant Shipping Act, 2025 replaced the former 1958 Act from 15 March 2026, and the regulator is now the Directorate General of Maritime Administration.

Related topics

Collision regulations (COLREGs) · Seamanship: anchoring, mooring and ship handling · GMDSS and maritime communication · Ship safety and fire fighting · Terrestrial, celestial and electronic navigation · ISM Code, SOLAS and marine safety management