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TL;DR: Voyage planning is the process of developing a complete berth-to-berth plan for a ship's passage, required by SOLAS Chapter V, Regulation 34 and carried out in four stages: appraisal, planning, execution and monitoring. Traditionally a static navigational document, the voyage plan has become a living, data-driven decision: modern voyage planning software builds the plan from live weather, vessel-specific fuel models and commercial constraints, and keeps optimising it while the ship sails.
What is voyage planning?
Voyage planning (or passage planning) is the development of a complete plan for a ship's voyage from berth to berth, covering the route, speeds, hazards, contingencies and the resources needed to execute it safely. It is a legal requirement: SOLAS Chapter V, Regulation 34 obliges the master to ensure a voyage optimisation plan is prepared before departure, using appropriate charts and publications, for every voyage.
The plan is both a safety document and, increasingly, a commercial one: the same choices of route and speed that keep the vessel safe also determine fuel consumption, arrival time, Charter Party compliance and emissions. Treating it as paperwork is the most common and most expensive mistake in the discipline.
The regulatory framework
Three instruments define what a voyage plan must be.
SOLAS Chapter V, Regulation 34 is the obligation. It requires that the intended voyage is planned using appropriate nautical charts and publications, taking into account any relevant ships' routeing systems, ensuring sufficient sea room, anticipating known navigational hazards and adverse weather, and considering marine environmental protection measures. In practice: a documented berth-to-berth plan, prepared before departure, that the bridge team can execute and monitor.
IMO Resolution A.893(21), Guidelines for Voyage Planning, is the method. It sets out the four-stage approach, appraisal, planning, execution and monitoring, that the industry has adopted as standard, and makes clear that planning covers the whole voyage from berth to berth, including pilotage waters.
The ISM Code is the accountability. It requires the company to establish procedures for key shipboard operations concerning safety, which in practice means the voyage plan is auditable: it must exist, follow company procedure, and be verifiable after the fact.
Two points are commonly misread. First, the obligation is berth to berth, not sea passage only: the plan must cover departure, pilotage and arrival. Second, the regulation sets a floor, not a ceiling. Nothing in Regulation 34 prevents the plan from also being commercially optimised, and nothing requires it to be static once approved. That headroom is where modern practice has moved.
The four stages of voyage planning
IMO guidance breaks voyage planning into four stages, and the discipline is remembering that the plan is not finished at departure:
Key operational considerations
The four stages describe the process. These are the factors that decide whether the plan survives contact with the voyage.
Draught, squat and under-keel clearance. Cargo and ballast condition set the draught, and the draught sets which routes and berths are available at which states of tide. Squat at speed in shallow water is a real constraint, not a theoretical one, and it interacts with speed decisions: the fastest passage through a shallow channel may not be an available one.
Tides, berth windows and pilotage. Arrival is rarely a single time; it is a window bounded by tide, pilot availability and berth occupancy. A plan that optimises sea passage and ignores the tidal gate at the destination has moved the problem rather than solved it.
Emission control areas and fuel changeover. ECA boundaries require compliant fuel inside the zone, which means planning the changeover, the tank capacity and the timing before the boundary, not at it. Getting this wrong is both a compliance exposure and a cost: MGO typically runs $80 to $150 per tonne above VLSFO.
High-risk and war-risk areas. Piracy high-risk areas, war-risk zones and their insurance implications constrain routeing independently of weather and economics. Underwriter notification requirements and transit conditions belong in the appraisal stage, not discovered en route.
Canal and chokepoint transits. Canal booking windows, transit slots, congestion and fees make a canal a scheduled resource rather than a geographic feature. A canal choice is frequently a commercial decision that outweighs the routeing difference, which is why it should be re-testable rather than fixed at fixture.
Bunkering stops and stem planning. Where the vessel bunkers affects the route, the schedule and the fuel cost of the remaining voyage, and the cheapest stem on this leg is not always the right one for the voyage. On multi-leg voyages this becomes a sequencing problem in its own right.
Weather and seasonal routeing. Forecast conditions, seasonal load line zones and climatological routeing all shape the plan before any optimisation runs. This is where weather routing does its work.
Contingencies and abort points. A plan without alternatives is a hope. Ports of refuge, abort points and contingency anchorages should be identified in the plan, with the conditions that would trigger them.
Communication and shared understanding. The plan has to be understood identically by the master, the bridge team and the operator ashore. Most plan failures in practice are not analytical failures but alignment failures: two parties working from different assumptions about the same voyage.
From static passage plan to optimised voyage
The traditional weakness of voyage planning is that the plan was static while the voyage is not: weather shifts, orders change, ports congest. A plan drawn on departure day decays from the moment the ship sails.
Voyage planning software closes that gap, and the best of it goes further than digitising the paperwork. Built on live weather data, weather routing, vessel-specific fuel models and the voyage's commercial constraints, the plan becomes the starting point of continuous voyage optimisation: every forecast update re-tests the plan, and improvements are proposed with their fuel, schedule and emissions impact quantified. Predictive voyage planning, in other words, rather than retrospective correction.
Speed is the lever this most often moves. The right speed for a leg is a function of the arrival window, the forecast, the hire cost of extra days and the vessel's carbon exposure, which is why blanket policies give way to per-leg speed optimisation. Accurate execution data flows back through vessel reporting, closing the loop for the next voyage.
Voyage planning vs weather routing vs voyage optimisation
These three terms are used interchangeably and are not interchangeable. The distinction is what each one optimises for, and whether it is an obligation or a choice.
Put simply: voyage planning is the obligation, weather routing tells you where to sail, and voyage optimisation decides how the whole voyage makes money. Planning is not optional; the other two are choices about how well you do it.
Voyage planning software: what to look for
Four things separate a planning tool from a decision tool:
- Live weather and routing built in, not bolted on, so the plan is generated against forecast conditions rather than annotated afterwards.
- Vessel-specific fuel models rather than class averages. ZeroNorth's are DNV-verified at 93.8% median accuracy. Class-average curves produce savings that exist only on paper.
- Charter Party and emissions constraints handled inside the plan, so a proposal that breaches a speed warranty or the CII budget never reaches the operator as a recommendation.
- One shared view for ship and shore, because a plan the bridge does not trust is a plan the bridge works around.
If a tool only draws the route and files the plan, it digitises stage 2 and ignores stages 3 and 4, which is where the money and the risk live. The full selection framework, including the vendor landscape and a demo checklist, is in the buyer's guide to voyage optimisation platforms.
The bottom line
Voyage planning is a SOLAS obligation, but treating it as paperwork wastes its commercial value. Planned, executed and monitored with live data, and built around the operational realities of draught, tide, ECA boundaries and canal windows, the voyage plan becomes the instrument that cuts fuel, protects the Charter Party and keeps emissions exposure visible, from appraisal to arrival. Book a demo to see berth-to-berth planning and optimisation in one workflow.
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