Passage Planning Fundamentals

What a Passage Plan Is

A passage plan is a written document that describes how you intend to get from departure to destination — the route, the hazards, the weather expectations, the timing, the contingencies, and the decision points along the way. It exists so that every crew member understands the voyage before it begins, and so that decisions made under pressure at sea are informed by thinking done in calm conditions ashore.

Why paper still matters: A chartplotter with a route loaded is not a passage plan. It's a line on a screen. A passage plan includes the reasoning behind the route — why you chose that track, what hazards lie on either side, where you'll shelter if conditions deteriorate, what tidal gates you need to hit, and what the abort criteria are. This context lives on paper (or a printed document), not in the chartplotter's memory.

The legal dimension: Under the International Convention for the Safety of Life at Sea (SOLAS), commercial vessels are required to carry a passage plan. Recreational vessels are not legally required to, but the standard exists because passage planning saves lives. The coast guard and SAR services can respond faster and more effectively when they know your intended route, your ETA, and your boat's description.

The Plan-Brief-Execute-Debrief Cycle

Professional mariners use a four-phase cycle for every passage. Recreational sailors who adopt this cycle make better decisions and have fewer emergencies.

Plan: Research the route, weather, tides, and hazards. Select waypoints. Identify contingency harbours. Calculate fuel and provisions. Write the passage plan document. This happens ashore, with access to resources, internet, and a clear head.

Brief: Before departure, the skipper briefs the entire crew on the passage plan. Everyone should know: the route and expected duration, the weather forecast and what deterioration looks like, the watch schedule, the contingency plans, the location of safety equipment, and the communication schedule. A crew that understands the plan can make good decisions even if the skipper is incapacitated.

Execute: Sail the plan. Monitor progress against the plan's assumptions — is the weather matching the forecast? Is the boat making the expected speed? Are the tidal gates being met? When reality diverges from the plan, the plan provides the framework for deciding what to change.

Debrief: After arrival, review the passage. What went well? What didn't match the plan? What would you do differently? This is how passage planning improves over time — each debrief feeds better planning for the next voyage. Keep a passage log with notes for future reference.

Route Selection and Waypoints

Route selection is the core of passage planning. The shortest route is rarely the best route — weather, currents, hazards, traffic, and available shelter all influence the optimal track.

Factors in route selection: (1) Weather exposure — does the route cross areas exposed to forecast weather from a dangerous direction? (2) Currents — can you use favourable currents or avoid adverse ones by timing or routing? (3) Hazards — rocks, shoals, traffic separation schemes, fishing gear areas, military exercise zones. (4) Shelter — are there bolt-holes (contingency harbours) along the route if conditions deteriorate? (5) Traffic — does the route cross shipping lanes, and if so, at what angle and in what visibility?

Waypoint placement: Waypoints should be placed at decision points and course changes, not at arbitrary intervals. Every waypoint should have a purpose — a course change, a tidal gate, a point where you assess conditions before continuing, or a decision point where you choose between continuing and diverting. Avoid placing waypoints on top of hazards — offset them to give a clear margin.

The 'what if' test: For every leg of the route, ask: what happens if the wind shifts 90 degrees? What happens if visibility drops to 100 meters? What happens if the engine fails? If the answer to any of these is 'we're in serious trouble,' the route needs adjustment — more sea room, a different track, or an additional contingency plan.

Float Plans and Filing

A float plan is a simplified version of your passage plan left with someone ashore — a trusted contact who will raise the alarm if you don't arrive or check in on schedule. It is the single most important safety document for a recreational sailor.

What a float plan includes: Boat name, description, and registration number. Number of crew and names. Departure point and time. Destination and expected arrival time. Planned route (in general terms). Communication schedule (when you'll check in and by what means). Safety equipment aboard (life raft, EPIRB, flares). Emergency contacts. The trigger: what the shore contact should do if you don't arrive or check in — typically, call the coast guard after a specified overdue period.

Who to file with: Leave the float plan with a responsible person ashore — a family member, a marina office, a yacht club, or a friend who understands boats. The coast guard in some countries (notably the US and Canada) accepts float plans directly. Some marinas and harbour masters will hold a copy.

The check-in schedule: Agree on regular check-in times — daily or twice-daily for offshore passages, at departure and arrival for coastal day sails. Specify the communication method (phone call, text, satellite message, VHF relay). If you miss a check-in, the shore contact should attempt to reach you before alerting authorities — a missed check-in may be a communication failure, not an emergency.