Planner Help

Complete guide to the free public beta: what to press, where it is, and what to do when something fails.

1. Before you start

Device and browser

• Use a current version of Chrome, Edge, Firefox or Safari. The route is calculated on your own device, which needs WebAssembly and Web Workers. All current browsers have both.
• A laptop or desktop is best for long passages, ocean routes, Finer/Finest detail and departure-window scans. Phones and tablets work well for coastal, lake and short routes, but can run out of memory on very large ones.
• Keep the tab open and in front while a route calculates. Phones pause background tabs, so switching apps can stall or stop the calculation.
• Content or ad blockers that block tile.openstreetmap.org or tiles.openseamap.org leave the map blank. Allow those sites if the map does not appear.

Time zone

Every time in the planner is Central European Time (CET in winter, CEST in summer, the time in Poland and Germany), whatever time zone your device uses. That applies to Set sail at, Target arrival, the ETA and every time in the route instructions. If you are in the UK, add one hour when entering times. If you are in Finland or the Baltic states, subtract one hour.

Fair-use limits

The service is free, so each internet connection can request a limited number of routes. By default that is 10 per minute, 120 per hour and 500 per day. Everyone on the same Wi-Fi or mobile network may share one allowance. If you reach a limit, the planner tells you which one and how long to wait.

• Each press of Calculate route or Analyze drawn route counts as one request.
• If you set a shore clearance and it blocks the route, the planner automatically tries again with zero clearance, which uses a second request.
• If no coastal route exists at all, it tries the ocean scale as well, which can use one more. A failing route in narrow water therefore costs two or three of your requests, not one.
• Pressing Calculate again within 10 minutes without changing anything reuses the data already prepared and does not count.
• When many people plan at once, you may see "The planner is busy". Wait a minute and try again.

2. Where everything is

On a computer the settings panel is on the left and the map on the right. On a phone the map is at the top and all settings, the Calculate button and the results are below it; scroll down.

3. Your first route, step by step

The page opens with an example Baltic passage already loaded. Press Calculate route to try it, or follow these steps for your own trip.

1. In Vessel, press Sailing or Motor.
2. In Positions, make sure Optimize is selected.
3. Press Set next to Start. The button lights up. Click or tap the map where you leave, in open water: a few hundred metres outside the harbour entrance, not on the quay. A green dot appears.
4. The planner switches to Destination for you, so simply click the map where you want to arrive. A red dot appears. Further map clicks keep moving the destination; press Set next to Start whenever you want to move the start again.
5. Sailing: enter your Calibration speed (see Sailing settings). Motor: choose the Motor route type and enter your Cruise limit.
6. Optional: enter Set sail at (CET/CEST). Leave it empty to leave now.
7. Press Calculate route. The button shows Calculating, a progress bar appears under it, and Cancel appears next to it.
8. When it finishes, the route is drawn in teal and the map zooms to it. Read the ETA, open Why this route?, check the leg list, and click any part of the route on the map to see the wind and current on that leg.
9. Heard a different forecast on the radio? See Weather updates from a bulletin.
10. To keep the route, press GPX (for chartplotters and navigation apps) or JSON (full data).

4. Positions: start, destination, examples

Why did my point move? The planning map is simpler than a real chart, so harbours, marinas and narrow inlets often count as land. When a point lands on modelled land or inside the shore buffer, the planner moves it to the nearest modelled water and says so, for example "Adjusted destination 3.8 km to nearby modeled water". If it is moved too far, place the point further out in open water and plan the last part into the harbour yourself.

5. Vessel: motor and sailing settings

Vessel profiles

Open Vessel profiles (+), type a Profile name and press Save to store your boat and safety settings (vessel type, speeds, fuel, shore clearance, depth). Choose a profile in Saved profile and press Load to apply it, or Delete to remove it (you are asked to confirm). If a profile is selected, Save overwrites it; choose Choose profile first to save a new one.

Profiles are stored only in this browser on this device. They do not sync between devices and disappear if you clear site data or use a private window.

Motor settings

Sailing settings

6. Navigation: time, scale, clearance, charts, current

Long passages and narrow water

For a passage that crosses a strait, Auto plans it in phases through fixed gates and joins them, for example Atlantic or North Sea to the Baltic through the Skagerrak and the Great Belt. That is what Strategic phase 3/5… in the progress line means. Three things are worth knowing before you trust a long line:

• A long passage outlives its forecast. Lisbon to Gdańsk under sail takes about three weeks; no forecast reaches that far. The planner still plans it: past the end of the forecast it holds the last values and keeps going, and the message after the route tells you where that starts. The coastal wind forecast reaches about five days ahead and the ocean one a few days further, so on a passage of a week or more the last part is planned on held wind. Treat those legs as a rough plan: replan from your position with a fresh forecast as you go, or plan the passage as legs (Lisbon to Brest, Brest to Skagen, Skagen to Gdańsk).
• Canals and the narrowest straits are not in the map. There is no Kiel Canal, Suez, Corinth or Göta canal, and the Bosphorus, the Dardanelles and similar channels are narrower than the grid, so routes through them fail. Plan up to one end and onward from the other.
• On a long leg the line can clip a narrow spit, a skerry or a small island. The grid covers the whole leg with a fixed number of cells, so on a passage of hundreds of miles each cell is several kilometres wide and land narrower than that can fall between the checks, even on Coastal scale. In a test of 30 long passages it happened on four, each time for a kilometre or two: the Norwegian south coast, the spits west of Rügen and the Stockholm archipelago. Check narrow sections against a chart, and plan an approach through islands or an archipelago as its own short leg, where the grid is dense enough to see them.

7. While the route is calculating

1. Preparing local planning data: the server loads the coastline, your no-go zones and the forecast for the area. Usually a few seconds; up to about 30 seconds for long passages, fresh forecasts or when the planner is busy.
2. Computing locally…: your device searches for the best route. Seconds for coastal routes, tens of seconds for long passages, and minutes for ocean routes, Finest detail or departure scans.
3. If the first attempt is blocked, you may see Retrying locally with zero shore-clearance buffer.

Press Cancel to stop. The Calculate button stays disabled until the current calculation ends, so a second press cannot start a duplicate. Do not reload the page or switch apps on a phone while calculating.

Before anything is sent, the planner checks your numbers. If a field is empty or out of range, it is outlined in yellow and reset to a valid value, and a red message lists what changed. Check the value and press the button again.

8. Reading the result

Colours on the map

• Teal line: the selected route. Click any part of it for the leg inspector (COG, SOG, wind, current, clock time).
• Dashed yellow line: straight line from start to destination, for reference.
• Dashed orange line: the baseline comparison route (or the grid route when the baseline was selected).
• Thick orange segments: auxiliary engine legs where sailing alone could not get through.
• Red dots: modelled obstacles. Red shaded polygons: your active no-go zones (grey dashed when switched off).
• Arrows: wind at departure time (pointing where the wind blows to) and, with the current layer on, current.
• Blue/yellow/red RPM line: engine load for RPM/fuel routes.
• A red ! marker in a dashed circle means the shore clearance closes a known passage; click it for the suggested clearance.

9. Drawing your own route

1. In Positions, press Draw route.
2. Click the map for the start, then for every turning point, and finally the destination. The numbered markers are waypoints; the first is the start and the last the destination. If Start and Destination were already set, they become waypoints 1 and 2 and your clicks are added after the destination. Press Clear first to start from scratch.
3. To adjust: drag a numbered marker; click on a leg to insert a waypoint there; press × in the waypoint list to remove one; Undo removes the last; Clear removes all (you are asked to confirm when there are more than two).
4. Press Analyze drawn route. Your line is not changed. Each leg is checked for land and no-go zones, and for whether the boat can hold that course in the forecast wind and current at the time it gets there.
5. Red legs must be changed. Hover a red leg to see why: crosses land or no go, cannot hold drawn cog in wind or current (for example straight into the wind), current prevents drawn cog or waypoints too close. Legs after an invalid one have no arrival time.
6. If every leg is valid and there are at most 12 waypoints, a dashed yellow suggested improvement may appear. Press Apply to move that waypoint (it is re-analysed automatically) or × to ignore it.
7. Export GPX or JSON once the route is feasible. Up to 50 waypoints are supported.

10. Weather updates from a bulletin

When a VHF, Navtex or coastal radio bulletin differs from the forecast the planner used, for example "southern Baltic, 6 to 7 to 8", enter it and replan. Weather updates work for sailing routes and need an internet connection: the replan loads the latest forecast first and then applies your update on top.

1. With Sailing selected, open Weather updates (+) in the Vessel section.
2. Area: Whole route area (most bulletins cover a whole sea area), or Draw on map: tap around the area and press the check button on the map.
3. From / Until: From starts at now. Press +6 h, +12 h or +24 h, or enter the times from the bulletin (CET/CEST).
4. Wind force: tap the Beaufort numbers in the order you heard them. For "6 to 7 to 8" tap 6, 7, 8. The undo arrow removes the last one.
5. Wind from: leave Keep forecast direction unless the bulletin gives a direction.
6. Read the comparison under the form. It compares the update with the wind on your current route in that area and time, and says whether replanning is worthwhile.
7. Press Add update, then Calculate route. At sea, first move Start to where you are (or turn on live GPS and use Replan from current position) and clear Set sail at so the route starts now.

What you hear, what you tap

How the update is combined with the forecast

• The forces are spread over the time window: for "6 to 7 to 8", force 6 at From, 7 halfway and 8 at Until, changing gradually in between.
• Where the forecast already falls within that force, it is kept, including its local detail such as shelter behind islands.
• Where it does not, the wind speed is moved to the nearest edge of that force. A force 5 forecast becomes 28 kn if the bulletin says 7. Force 6 is 22-27 kn, 7 is 28-33 kn, 8 is 34-40 kn.
• The wind direction from the forecast is kept unless you choose one.
• A drawn area fades out over a few kilometres beyond its edge, and the update eases in and out over an hour, so rough input does not create sudden walls of wind.
• The planner does not steer you away from strong wind. Whether the conditions suit your boat and crew is your decision.

Reading the result

• A message says how much of the area and time the update changed, for example "forecast 4-6 Bf, now 7-8 Bf", or that the forecast already matched.
• If you calculated the same destination before, the previous plan is drawn as a dashed grey line and the message says how much earlier or later you now arrive.
• Legs inside an update are marked weather update in Route instructions. The wind arrows and the leg inspector show the updated wind.
• Untick an update to plan without it, or press × to delete it. Updates are not saved: reloading the page removes them.
• Updates are not used for motor routes, because motor routing does not use wind, or for drawn routes.
• If an update's times are outside the forecast used for the route, or its drawn area is outside the route's planning area, the message says so and the update is not applied.

11. No-go zones

No-go zones are areas the route must never enter: a missing island, shallows, a firing range, a traffic separation scheme, or anywhere you simply do not want to go.

1. Press the pentagon button on the right side of the map (Draw a custom no-go zone). It lights up.
2. Click at least three points around the area (at most 200).
3. Press the check button directly below the pentagon to finish. Pressing the pentagon again cancels the drawing.
4. The zone appears in No-go zones in the Positions section. Rename it there, untick it to ignore it without deleting it, or press × to delete it.
5. Calculate again. Zones are hard rules: the route goes around them or fails.

• Up to 20 active zones. Untick or delete some if you need more.
• The trash button at the bottom of the map buttons deletes all zones after a confirmation.
• A zone drawn across a strait or harbour entrance can make the destination unreachable. If a route suddenly fails, untick your zones and try again.
• Zones are not saved. Reloading the page removes them.

12. Live GPS position

• Press the crosshair button at the far right of the top bar, confirm, then allow location access when the browser asks.
• Your position becomes the Start and keeps updating it as you move. A track line and an accuracy circle are drawn; the badge at the bottom left shows GPS accuracy.
• The top bar shows Live position, or Position stale when no update has arrived for 20 seconds (indoors, screen locked, weak signal).
• With a route on the map, the status line shows how far you are from it. Replan from current position recalculates from where you are now.
• The eraser map button clears the track line.
• GPS needs a secure (https) page and location permission. If you blocked it, re-enable location for this site in your browser settings.

13. Map buttons

From top to bottom on the right edge of the map:

14. Limits at a glance

15. When something goes wrong

Messages appear at the bottom of the map. Find the start of your message below.

Messages before calculating

Limits and server messages

Route could not be found

The route looks wrong

Still stuck? Press Feedback in the top bar and describe what you did: vessel type, the settings you changed, roughly where the start and destination were, the exact message, and any reference code.

16. Data sources and privacy

• Base map: © OpenStreetMap contributors. Nautical marks: © OpenSeaMap contributors.
• Coastline: OpenStreetMap land polygons for supported European waters, and Natural Earth elsewhere. Inland water: OpenStreetMap.
• Coastal wind: NOAA GFS 0.25° forecast. Ocean wind and fallback wind: Open-Meteo. Currents: Open-Meteo marine API (Météo-France SMOC). Open-Meteo data is licensed under CC BY 4.0.
• The route search runs in your browser. To prepare map and forecast data, the server receives your start, destination and settings; see the Privacy notice for how that is handled.
• Vessel profiles stay in your browser. If Data and privacy appears in the panel, route analytics are strictly opt-in, use coarse area bands only, and can be deleted with Delete my shared outcomes.