Question 1

You are setting up ECDIS before a coastal passage. Your vessel drafts 8.4m. Your examiner asks you to explain how you would set the safety depth, safety contour, and shallow water contour, and why these settings matter.

Accepted Answer

Safety depth: set to the vessel's maximum draft (8.4m) plus a UKC margin — e.g. 10m. Soundings shallower than this are displayed in a contrasting colour. Safety contour: the depth contour at or just deeper than the safety depth — spot soundings inside this contour trigger the anti-grounding alarm. Shallow water contour: marks the boundary where restricted manoeuvring begins — typically set at 1.5-2x the safety depth. These settings directly control when alarms fire and when colour changes occur. Incorrect settings (e.g. safety contour left at default 30m when draft is 8.4m) give a false sense of security and can mask genuine hazards. Incorrect ECDIS safety settings are cited in multiple grounding investigations. The IHO S-52 standard and IMO performance standards (MSC.232(82)) require the mariner to set these values — they have no meaningful defaults. Key chain: Safety Depth → controls colour of individual soundings (red/yellow when shallower than setting). Safety Contour → the most important setting: ECDIS selects the nearest available depth contour at or deeper than this value; the anti-grounding alarm fires when the vessel crosses this contour. If no exact contour exists in the ENC for your chosen depth, ECDIS selects the next deeper available contour — this can result in NO alarm in areas with sparse contour data. Shallow Contour → typically set at 2x draft for early situational awareness. OOWs must verify these at every voyage and after every draft change.

Question 2

Your examiner asks: "What does SOLAS Chapter V Regulation 34 require regarding passage planning, and what are the four stages of passage planning?" Give a complete OOW answer.

Accepted Answer

SOLAS V Reg 34 requires that before proceeding to sea, the master shall ensure that the intended voyage has been planned using adequate and up-to-date charts and nautical publications. The four stages are: APPRAISAL (gather all relevant information); PLANNING (lay the plan on charts from berth to berth); EXECUTION (monitor progress against the plan); MONITORING (cross-check position continuously throughout the voyage). SOLAS V Reg 34 (Voyage planning) requires passage planning for ALL voyages — there is no distance threshold. IMO Res. A.893(21) "Guidelines for Voyage Planning" expands on the four stages. APPRAISAL: collect charts, publications, NOTAMs, weather, port information, draft restrictions, tidal windows. PLANNING: no-go areas, waypoints, abort points, contingency anchorages, speed profiles. EXECUTION: confirm plan implemented at departure and each watch handover. MONITORING: continuous position fixing, comparison with plan, CPA checks on all traffic. "Berth to berth" is the key phrase — the plan must cover the vessel from the departure berth to the arrival berth, including port approaches.

Question 3

During passage appraisal, you identify a shoal with 6.5m charted depth on your route. Your vessel drafts 7.2m. Describe how you would handle this in the passage plan.

Accepted Answer

The shoal is a no-go area. You would draw a no-go zone on the chart with a safety margin added for squat, wave response, tidal variation, and chart accuracy. A clearing bearing or limiting danger line would be drawn to keep the vessel safely clear. The passage plan waypoints must route the vessel outside this zone. The abort point where you could no longer safely turn back or divert must also be marked. A charted depth of 6.5m with a draft of 7.2m means zero underkeel clearance — the area is a no-go zone regardless of tidal height. Tidal heights add water but introduce uncertainty (sounding datum, tidal prediction errors, storm surge/set-down). The safety margin for no-go areas must account for: squat (speed-induced sinkage); heel; tidal prediction error; chart datum uncertainty; wave response; and sea state. A clearing bearing is a compass bearing drawn on the chart: as long as the bearing to a landmark or buoy is greater/less than the charted value, the vessel is safe. Limiting danger lines run parallel to the track at the minimum safe passing distance from the hazard. Both are standard passage planning tools examined at OOW level.