What are the four stages of passage planning (appraisal, planning, execution, monitoring)?

Passage planning, required under SOLAS chapter V and central to safe navigation on every voyage, whatever the ship's size or trade, is built around four recognized stages, appraisal, planning, execution and monitoring, that together take a voyage from a general idea of where the ship needs to go to a safely and continuously monitored passage carried out berth to berth, including the confined pilotage waters at each end, not just the open sea portion in between.

Appraisal is the information gathering and risk identification stage: collecting and studying every relevant chart and publication, tide tables and tidal stream information, currents, expected weather and any seasonal hazards, the ship's own draught, air draught, manoeuvring characteristics and under keel clearance requirements, and any mandatory routing, reporting or pilotage requirements along the intended route, so that the real risks and constraints of the voyage are properly understood before a single line is drawn on the chart. Skipping or rushing appraisal is how a plan ends up technically drawn but practically unsafe.

Planning takes that gathered information and turns it into the actual route, laid off on the charts, now almost universally in ECDIS, marking planned courses and distances, identified no-go areas and safety contours the ship must not cross, wheel over points for course alterations, abort positions and bail out options if a manoeuvre such as a pilotage or a tricky passage cannot be completed as intended, contingency anchorages, and the safety margins the plan keeps from every charted danger; a well built ECDIS route also uses the system's automatic route checking function to flag any point where the plan crosses the ship's safety contour or a charted hazard before the voyage even begins.

Execution is carrying the plan out on the day, adjusting timing where needed to real conditions rather than following the plan blindly, for example timing arrival at a shallow or tidally constrained passage to catch a favourable tide, adjusting speed to meet a pilot boarding time, and briefing the bridge team and, where relevant, exchanging information with the pilot on boarding so that everyone shares the same understanding of the plan being executed, an exchange required precisely because pilotage waters are where a large share of groundings and collisions actually happen.

Monitoring runs continuously throughout the passage rather than being a discrete final stage: the ship's actual position is checked against the planned track by every available means, visual bearings, radar, GPS and ECDIS cross referenced against each other rather than trusted blindly from a single source, so that any deviation, whether from current, wind, human error or equipment fault, is detected early and corrected before it becomes dangerous. The plan is prepared by the navigating officer and formally approved by the master before the voyage begins, but monitoring and, where circumstances genuinely require it, replanning during the voyage remain a live responsibility of the whole bridge team for as long as the ship is underway.