Question 1

As Master of a vessel departing Rotterdam for Singapore, describe the legal requirement for passage planning under SOLAS V/34 and your approval process.

Accepted Answer

SOLAS V/34 — PASSAGE PLANNING LEGAL REQUIREMENT: THE REGULATION: SOLAS V/34 requires that "prior to proceeding to sea, the Master shall ensure that the intended voyage has been planned using the appropriate nautical charts and nautical publications for the area concerned." THE REQUIREMENT IS: (1) BERTH-TO-BERTH: the passage plan must cover from the berth of departure to the berth of arrival. Not just the ocean passage — including port approaches and harbour transits; (2) APPROPRIATE CHARTS AND PUBLICATIONS: the latest editions of charts, pilot books, sailing directions, light lists, tide tables. ECDIS ENCs must be on the latest versions. NtMs must have been applied; (3) ALL RELEVANT INFORMATION CHECKED: (a) Meteorological and oceanographic conditions; (b) Traffic separation schemes; (c) Planned speed and ETA; (d) Tidal windows for port entries and exits; (e) Hazards and no-go areas; (f) Alternative ports and contingency plans; (g) Piracy/security considerations (the route includes Malacca Strait and Indian Ocean HRA); (4) MASTER APPROVAL: the chief officer typically prepares the passage plan; the MASTER must APPROVE it. The master is legally responsible for the passage plan under SOLAS V/34; THE APPROVAL PROCESS: (a) Review at each section: appraisal, planning, execution, monitoring; (b) Verify no-go areas correctly programmed in ECDIS; (c) Check safety contours set appropriately; (d) Confirm XTE alarms; (e) Verify pilot boarding positions, TSS entry/exit waypoints; (f) Sign the passage plan (legal evidence of approval); (5) MASTER RETAINS AUTHORITY: the pilot does NOT override the passage plan. The master is responsible for the plan throughout. IMO Resolution A.893(21) — Voyage Planning Guidance: the IMO guidance on voyage planning under SOLAS V/34 specifies the four-stage process: APPRAISAL (gathering information), PLANNING (setting the plan), EXECUTION (monitoring the plan underway), MONITORING (continuous review). All four stages require the master's oversight. The chief officer prepares — the master approves and is accountable. Berth-to-berth: the UK MCA has specifically enforced this. Following an incident where a vessel grounded in a port approach because the pilot was not following the vessel's passage plan and the master had no plan covering the approach — the MCA concluded the master was in breach of SOLAS V/34 by not having a plan covering the port approach. All passage plans must cover berth-to-berth. Pilot authority (option B): the pilot is an advisor — they have local knowledge but do not create or override the SOLAS V/34 passage plan. The pilot boards and navigates the vessel using their expertise in the pilotage area — but the master's berth-to-berth passage plan must include the pilotage section. The master remains responsible. Chief officer responsibility (option D): the chief officer prepares the passage plan as a normal SMS duty — but the MASTER APPROVES it. SOLAS V/34 is explicit that the responsibility lies with the master. A passage plan that the master has not reviewed and approved does not fulfil the SOLAS V/34 obligation. Rotterdam to Singapore ISPS: the passage plan for Rotterdam-Singapore must include security assessment for: Malacca Strait (historically piracy-affected, SOLAS XI-2 security), Indian Ocean HRA (BMP6 measures), Gulf of Aden (UKMTO registration, IRTC waypoints).

Question 2

Your 180m bulk carrier is in Force 10 seas in the North Atlantic on a westbound Atlantic crossing. What are your strategic options and how do you decide?

Accepted Answer

FORCE 10 HEAVY WEATHER MANAGEMENT — STRATEGIC OPTIONS: FORCE 10 CONDITIONS: Beaufort 10 = 48-55 knots wind, seas 9-12m, very high waves with overhanging crests. For a 180m bulk carrier: (a) Green water on deck; (b) Risk of structural damage (hatch covers, mooring equipment); (c) Risk of cargo shift (particularly if bulk cargo has high moisture content); (d) Risk of parametric rolling (if heading or speed is near resonance frequency); STRATEGIC OPTIONS: (1) MAINTAIN COURSE — if the vessel can make safe headway, maintaining course at reduced speed may be appropriate. Rule: speed such that no excessive structural stress occurs. Fuel consumption penalty; (2) HEAVE-TO: bring the vessel to approximately 30-40° off the sea on the bow (head to sea, minimal headway). Most comfortable option for weathering out a storm. Significant time and fuel cost; (3) RUNNING BEFORE: stern to sea. Faster progress but: stern-on boarding seas risk; pooping risk; loss of rudder effectiveness in following seas (surf-riding, broaching risk); (4) AVOIDANCE — alter course to skirt around the storm. Use weather routing service data and ECMWF forecast to find the storm track and avoid it; MASTER's DECISION PROCESS: (1) ASSESS STORM TRACK: is it moving, and can you outrun or avoid it?; (2) VESSEL CAPABILITY: what is this vessel's seakeeping in these conditions?; (3) CARGO RISK: is the cargo susceptible to moisture or shifting?; (4) CREW CONDITION: fatigue level; (5) DESTINATION URGENCY: is there a berth window, laycan, tidal window that has commercial significance?; (6) NOTIFY DPA: commercial implications of significant deviation. Full speed in Force 10 (option B): maintaining full service speed in Force 10 conditions risks: (a) Excessive slamming (bow slamming in following steep seas); (b) Loss of propeller in following seas (RPM surge when propeller emerges); (c) Structural overstress on hatch covers, deck fittings; (d) Cargo damage. The correct principle is to reduce speed to what the vessel can safely sustain — which in Force 10 may be as low as 3-5 knots for safety. Running before the storm (option C): stern-on to following seas can cause: (a) Surf-riding — the vessel accelerates uncontrollably down a wave face, rudder loses effectiveness; (b) Broaching — a sudden involuntary turn athwart the sea; (c) Pooping — a following sea breaks over the stern. These are extremely dangerous. Running before the storm is appropriate only in certain vessel types and conditions — it is not universally the safest option. Weather routing authority (option D): the master bears responsibility for the safety of the vessel under SOLAS V/34 (passage planning). Weather routing services provide expert guidance — but they cannot compel the master to follow their recommendations. The master assesses the weather data and makes the decision. The weather routing service cannot be on the bridge to observe actual conditions. Parametric rolling — bulk carriers: certain vessel hull forms (bulkers, container ships) are susceptible to parametric rolling in specific sea states where the encounter frequency matches the natural roll period. The master must be aware of this and alter course or speed if the vessel exhibits parametric rolling characteristics.

Question 3

Your 300m tanker has a draught of 16.5m. You are transiting a channel where the charted depth is 19m but where dredging may have created uneven bottom. Discuss your UKC calculation and minimum clearance policy.

Accepted Answer

UKC CALCULATION — 300M TANKER IN SHALLOW CHANNEL: UKC COMPONENTS: Under-Keel Clearance = Charted Depth − Vessel Draught − Dynamic Allowances. STATIC CALCULATIONS: (1) Chart datum: the charted 19m is referenced to Chart Datum (Lowest Astronomical Tide). Current tidal height must be added; (2) Current draught: 16.5m; (3) Static clearance at chart datum: 19 - 16.5 = 2.5m; (4) During tidal rise: if tide = +1.5m: effective depth = 20.5m; clearance = 20.5 - 16.5 = 4.0m before dynamic allowances; DYNAMIC ALLOWANCES — THESE REDUCE THE EFFECTIVE UKC: (1) SQUAT: a vessel moving through water sinks below its static waterline due to: (a) Pressure distribution under hull; (b) Speed-dependent. For large vessels in shallow water (depth/draught ratio < 3): squat can be calculated using the Barras formula. At 10 knots in a depth/draught ratio of ~1.15 (19/16.5), squat for a 300m tanker may be 1.0-1.5m; (2) HEEL: when turning or in wind — the vessel lists, increasing draught at the lower side. For 1° heel at 32m breadth: heel squat ≈ 0.28m; (3) WAVE RESPONSE: in wave action, the vessel heaves and pitches — the lowest point may be deeper than the static waterline; (4) CHART ACCURACY: the stated 19m may not reflect uneven dredging. A safety margin of 0.5-1.0m should be added; MINIMUM SAFE CLEARANCE POLICY: many companies specify 10-15% of draught = 1.65-2.5m after all dynamic deductions. At 10 knots with 1.5m squat and heel — the available clearance BEFORE wave response and chart inaccuracy is: 2.5m (static) - 1.5m (squat) - 0.28m (heel) = 0.72m. THIS IS INSUFFICIENT for a 300m tanker. REDUCE SPEED to reduce squat. Static UKC is a starting point only: option B correctly identifies static UKC as 2.5m — but fails to account for any dynamic deductions. For a VLCC/large tanker in a shallow channel, squat alone can be 1.0-2.0m at normal transit speeds. The net dynamic UKC after squat, heel, and wave response may be less than 0.5m — critically insufficient. Pilot responsibility (option C): the pilot advises on local conditions and may have experience-based knowledge of the channel. However, the master retains ultimate responsibility for the vessel's safety (MSA 1995 S.22 and SOLAS V/34). The master should calculate UKC independently and compare with the pilot's recommendations. If the master's calculation shows inadequate UKC — they must raise this with the pilot. Speed and squat relationship: option D is dangerously wrong. Increasing speed INCREASES squat (squat is proportional to approximately speed squared). The correct response is to REDUCE SPEED to reduce squat. Many VLCCs transit shallow ports at very slow speed (4-6 knots) specifically to manage squat. Company UKC policy: most major oil company and bulk carrier operators have formal UKC policies specifying minimum clearances after all dynamic deductions. These are typically: (a) At sea: 10% of draught minimum (but often 1.5-2.0m absolute minimum); (b) In restricted waters: 15% of draught after deductions. The Barras formula: B2/Cb × V²/Lpp gives a squat estimate. This is the standard formula used by many harbour masters and pilots. Masters of large vessels should be familiar with its application.