Question 1

As Chief Mate on coastal watch approaching the Strait of Gibraltar, describe your watch monitoring techniques to maintain a safe and accurate position.

Accepted Answer

COASTAL WATCH MONITORING — GIBRALTAR APPROACH: THE MONITORING PHASE (APEM): monitoring is the active comparison of actual vessel position against the passage plan. POSITION FIXING INTERVAL: in coastal and restricted waters — minimum every 6 minutes (MCA guidance), ideally every 3 minutes in close proximity to danger. Interval should be such that if the vessel is off-track, the error is discovered while there is still time to act. POSITION FIXING METHODS — CROSS-CHECK EACH OTHER: (1) PRIMARY: ECDIS with GPS — shows position continuously. However, over-reliance on a single GPS fix is a risk. GPS can be spoofed or suffer signal error; (2) RADAR FIX: two or three radar range/bearing fixes from: Cape Trafalgar lighthouse (prominent radar target), Cabo Carnero (SE Spain), Punta Tarifa (most southerly point of mainland Europe). Radar ranges are typically more accurate than radar bearings in fixing; (3) VISUAL: if visibility permits, visual cross bearings from Tarifa lighthouse, Ceuta, Gibraltar Rock. Three visual bearings give a cocked hat — if large, repeat the fix; (4) CROSS-CHECK: GPS/ECDIS position vs radar fix. If they diverge by more than a safe margin (>0.1nm in restricted waters) — investigate immediately. Do not accept GPS without cross-check; MONITORING THE PLAN: (5) Is the vessel on track? Compare ECDIS vessel symbol against planned track; (6) Is the XTE (cross-track error) within set limits?; (7) Are the next waypoints still appropriate for current conditions?; (8) Check closing rate with traffic — AIS and radar. The Strait of Gibraltar is among the busiest waterways in the world. GPS vulnerability in Gibraltar area: the Strait of Gibraltar and Spanish/Moroccan coasts have been identified as areas with periodic GPS interference and spoofing. Several vessels have reported anomalous GPS positions in the western Mediterranean. Cross-checking GPS against radar is not just good practice — in some areas it is operationally essential. GPS spoofing: AIS positions (which use GPS) of vessels can appear displaced from actual positions when GPS jamming or spoofing is occurring. If the radar does not show a target where the AIS suggests one exists — or if a target's AIS position is inconsistent with its radar position — GPS interference may be present. Strait of Gibraltar traffic density: the Strait of Gibraltar handles approximately 40,000 vessel transits per year — around 110 per day. The TSS (through the Strait) is mandatory under COLREG Rule 10 for vessels using the Strait. Additionally, there are numerous ferry crossings between Spain and Morocco (Algeciras-Ceuta, Algeciras-Tarifa routes). Watch management in this area requires constant AIS and radar monitoring in addition to navigation. Fix frequency requirement: STCW A-II/1 (OOW competency) requires that officers determine the ship's position using all available means and at appropriate intervals. In coastal waters approaching the Strait — 3-6 minute intervals is the professional standard. In a casualty investigation — the interval between the last confirmed fix and the casualty event is always examined. Single-source navigation (option B): the MAIB has investigated multiple groundings where the single contributing factor was over-reliance on GPS/ECDIS without radar cross-checking. "The ECDIS shows us in the clear" was not an adequate defence when the GPS position was in error.

Question 2

As Chief Mate, you are responsible for preparing the passage plan for a voyage from Rotterdam to New York. Describe the APEM framework you use and what the master must approve.

Accepted Answer

PASSAGE PLANNING APEM FRAMEWORK: IMO Resolution A.893(21) — Voyage Planning Guidelines. The APEM framework has four stages: (A) APPRAISAL: gather all relevant information before planning: (1) Nautical charts — identify correct editions, apply NtM corrections. Use largest scale available for all coastal sections; (2) Nautical publications — Sailing Directions (NP27 Bay of Biscay, NP69 North Atlantic, US East Coast Pilot), Light Lists, Tide Tables, Tidal Stream Atlas; (3) Weather routing service — seasonal North Atlantic winter storm track, pilot charts showing prevailing winds, currents, ice limits; (4) Notices to Mariners — weekly, check latest edition NTMs for all charts to be used; (5) Ship's draught and UKC requirements at departure and arrival; (6) Vessel characteristics — manoeuvring data card, stopping distances; (P) PLANNING: using the appraisal information, plan the complete voyage: (1) Berth-to-berth — departure berth Rotterdam, arrival berth New York including pilot boarding ground; (2) Waypoints with clearing bearings/distances from dangers; (3) No-go areas — shoals, traffic separation zones, exclusion areas, offshore installations; (4) Abort points — last point to turn back to Rotterdam safely; (5) UKC calculations at critical shallow sections; (6) Speed calculations for pilot station arrival time and tidal window; (E) EXECUTION: monitoring the voyage against the plan; (M) MONITORING: comparing actual position against planned track throughout. MASTER APPROVAL: the Master must sign the plan before departure — SOLAS V/34 legal obligation. APEM standard — universal application: APEM applies to ALL voyages including ocean passages. The depth of each stage varies with voyage complexity, but an ocean Atlantic crossing requires: (a) seasonal weather routing consideration (North Atlantic in winter — Genco/Maersk weather routing service); (b) ice limit consideration (Grand Banks area — seasonal icebergs from March to August); (c) North Atlantic shipping lanes (SOLAS Regulation for routeing); (d) GMDSS provision for the sea areas (A1/A2/A3 coverage). Chief mate's role in passage planning: in practice, the chief mate prepares the voyage plan and presents it to the master for approval. This is standard industry practice reflected in STCW competence requirements for STCW II/2 (Chief Mate). The STCW Chief Mate Certificate of Competency examination includes passage planning as a key competency. Master sign-off requirement: the master is ultimately legally responsible under SOLAS V/34 for ensuring the voyage is properly planned. In practice, the master reviews and approves the plan — but the chief mate prepares it. The master's approval signature has legal significance in any investigation. Great circle only (option C): while great circle routing is the default for ocean passages, the passage plan must still consider: (a) ice limits in the Great Circle track area; (b) Traffic Separation Schemes; (c) pilot boarding grounds; (d) UKC at port approaches. A bare great circle with no additional planning is not a complete passage plan for a SOLAS V/34 purpose.

Question 3

As Chief Mate, it is your responsibility to maintain the vessel's ECDIS and charts. Describe your procedure for ensuring all charts are up to date for a voyage.

Accepted Answer

ECDIS AND CHART MANAGEMENT — CHIEF MATE'S PROCEDURE: ECDIS CHART MANAGEMENT: (1) ENC SOURCE: Electronic Navigational Charts (ENCs) are sourced through an authorised distributor — AVCS (Admiralty Vector Chart Service), PRIMAR, or equivalent national chart authority. The subscription must be current; (2) WEEKLY UPDATES: AVCS provides weekly ENC updates. The chief mate must: (a) connect the ECDIS to the update service weekly; (b) download and apply all updates to ENCs covering the upcoming voyage; (c) verify update application — some ECDIS systems show "cells updated" count; (3) NtM CHECK: for paper charts (on ECDIS backup charts or paper chart primary systems) — weekly Notices to Mariners (NtM) must be applied. UK Hydrographic Office NtMs are published weekly. Each NtM specifies the chart number and correction. Mark each chart in the NtM index with the correction number applied; (4) CORRECTION LOG: maintain a Chart Correction Log recording: chart number, edition, NtMs applied, date of correction. This is a statutory record; (5) CHART CATALOGUE: the Admiralty Chart Catalogue specifies which charts are required for the planned voyage. Ensure all charts are: (a) latest edition; (b) all NtMs up to the current week applied; (6) NEW EDITIONS: when a chart is re-issued (new edition), all previous corrections on the old edition become incorporated. Order the new edition and apply subsequent NtMs from the new edition date; (7) T&P NOTICES: Temporary and Preliminary Notices to Mariners (T&Ps) apply to ENCs as Cell Update information — check these separately from permanent corrections. Frequency of NtM updates: the UK Hydrographic Office (and other hydrographic offices) publish corrections weekly. The MAIB has investigated groundings where the cause was an uncorrected chart — the most common pattern is a temporary or preliminary notice that changed a depth, moved a buoy, or added a new hazard. Investigations routinely check when the last NtM update was applied. SOLAS standard: SOLAS V/27 requires ships to carry adequate and up-to-date charts. "Up to date" means NtMs applied to the current week. Outdated charts are a PSC deficiency. The MCA's Concentrated Inspection Campaign on navigational equipment in recent years specifically targeted NtM compliance. Automatic ECDIS updates (option C): ECDIS does NOT automatically update charts without action. The chief mate must: (a) have an active subscription to AVCS or equivalent; (b) download updates from the update server; (c) apply them to the ECDIS. The process is not automatic — many ECDIS groundings have involved failure to update ENCs. Chart Correction Log requirement: the requirement for a Chart Correction Log is implied by SOLAS V/27 ("adequate and up-to-date charts") and MCA MGN guidance. The Log is not explicitly required by a single SOLAS regulation but is standard practice and expected by PSC. In any grounding investigation — the chart correction log will be examined to verify the chart was current at the time of the incident.