Sailing Router is a free web tool that plans a sailing route between two points — or through several stopovers — using the latest wind and current forecasts and your boat's performance profile. The result is a waypoint-by-waypoint route with estimated timing, a map you can scroll and zoom, and downloadable files you can load into your chart-plotter or keep for offline use at sea.
It runs entirely in your browser. Nothing to install.
The story — Captain Eric and the Subic–Boracay Regatta
A while back my friend Captain Eric called. He was preparing his boat for the Subic–Boracay Regatta — a classic Philippine passage of two hundred-odd nautical miles down the western edge of Luzon, round the islands and on to White Beach. He was not calling for the weather gossip; he was calling with a clear ask: "Can you help me win this one?"
The honest answer was: I can't help you win — the wind and the fleet will decide that. But I can help you sail the right line. So I pulled together the tools I had — the forecasts, the currents, a polar for his boat — and stitched them into a little routing engine. We fed in the start, the finish, the departure hour, and the thing spat out a route that threaded the offshore breeze where the inshore fleet would be parked in the lee of Zambales.
Eric read it, nodded, and went sailing.
He finished 3rd !!!
That prototype is what you are looking at now. The Subic → Boracay passage is one of the eight routes on the showcase above — every few hours it is recomputed against the latest forecast, the same way Eric used it on race morning. The tool grew from there: more boats, more regions, more polars, a proper map, comfort settings, multi-leg routes. But the brief has not changed since that first phone call — help me sail the right line.
1. Getting started
1.1 Create an account
Click Register in the top-right of the landing page.
Enter an email address and a password (at least 8 characters).
Open the verification email and click the link.
You are now a verified user with 50 free route credits.
Credits pay for route computations: 1 credit per leg (see §7).
1.2 Log in
Use the Login tab with the same email + password.
If you forgot your password, contact support — a self-service reset flow is in the roadmap.
1.3 Plan your first route
Once verified you land on the Plan a Route tab. The shortest possible first run: type a departure port, type an arrival port, pick a boat, click Compute. Details of every field are in §3.
2. The landing page
Public to everyone (no account required):
Hero showcase — featured routes recomputed against fresh weather every few hours.
Showcase tab — eight recent routes across different regions. Click any card to open the route's map.
Regattas tab — a separate page with classic offshore races (e.g. Fastnet, Kiel Week). Same format as showcase, kept apart so the landing grid stays focused on general cruising passages.
Tidal stations counter — click it for a modal listing every harmonic station the router uses for coastal currents.
Donation link — opens a Stripe tip jar. Sailing Router is free; donations keep the servers running.
3. Planning a route
3.1 Picking start and end
There are three ways to set each location. All three write to the same hidden coordinates, so you can mix them freely.
Type a harbour name. The dropdown matches against a curated list of global harbours plus 20k+ marinas imported from OpenStreetMap and coastal city names. As you type, the country code (e.g. FRA) and rough coordinates are shown. Pick the match and the field is resolved.
The hemisphere letter (N/S/E/W) can come before or after the number.
Click on a map. Press Pick on map below the location fields to reveal an interactive map. The first click drops the departure pin (green S), the second drops the arrival pin (red E), the next clicks add stopovers (amber). Drag any pin to fine-tune its position. As you move the cursor over the map its live position is shown top-right. Pins that land on solid ground get a red outline — drag them out to water.
3.2 Picking a boat
The Boat Model field is a search box over 3,600+ performance profiles, including hundreds of real race-measured profiles plus curated generic profiles for common cruiser types. Type three or more characters to see matches; each result shows the brand and whether the profile is measured or estimated.
Once a boat is picked, a View polar matrix button appears. Hovering it shows the speed table (rows = wind speed, columns = wind angle) the router will use.
If your exact boat isn't in the list, pick the closest match — the engine falls back hierarchically (exact model → same brand + same type → same type → generic cruiser).
3.3 Departure time
The date / time picker defaults to now + 1 hour in your browser's local time zone. The time zone you see above the map is always your browser's. Change it if you plan to leave later — the forecast used for each leg is the one valid at that moment.
3.4 Stopovers (multi-leg routing)
Press + Add stopover between the Departure and Arrival fields to add intermediate waypoints. You can add up to 5. Each stopover:
Supports the same three input methods (type, GPS, map).
Comes with ↑ / ↓ buttons to reorder and an ✕ to remove.
Gets its own amber pin on the map picker.
Each stopover adds 1 extra credit to the route cost (see §7).
3.5 Preset modes
Four buttons above the advanced options set the whole parameter block in one click:
Race — no comfort limits; fastest possible route, exploring tight corners of the polar.
Active — moderate limits; fast but avoids dangerous wind / wave combinations.
Comfort — conservative; caps wind at 20 kt, waves at 3 m, requires a minimum 50° wind angle, avoids beam seas, prefers daylight sailing.
Custom — unlocks every individual advanced option.
3.6 Advanced options (Custom mode)
Efficiency — 100 % uses the full polar; lower values scale it down to account for sail condition, crew fatigue, reefing, etc.
Max wind — the route will avoid areas where forecast wind exceeds this threshold.
Max wave — significant wave height ceiling in metres (2 m calm / 3 m moderate / 4 m standard / 5 m rough).
Min TWA — minimum angle off the wind; prevents extreme upwind slogs.
Avoid beam seas — when on, the solver penalises routes with seas on the beam.
Night mode — penalises sailing after dark (useful for short-handed crews).
Min speed — if the polar predicts less than this, the router considers running the engine.
Motor speed — the speed to use when the engine is on. Setting this to 0 disables motoring.
Greediness — how eagerly the solver rushes toward the destination versus exploring alternatives. Default is fine for most routes.
Corridor — how far off the great-circle line the solver is allowed to search, in nautical miles. Default 1200 (covers ocean-crossing detours); narrow it for fast direct passages.
3.7 Compute
Press Compute to submit. You'll see a polling panel with an estimated duration. Typical solve times: a few seconds to a minute or two, depending on route length and corridor width.
If any of the waypoints sit outside the forecast coverage, or if the route can't be found (e.g. the start is landlocked), the compute fails cleanly and your credits are refunded automatically.
4. Reading the result
The result card appears below the form with:
A one-line summary (duration, distance, comfort score).
A safety disclaimer.
An interactive map with the full track.
Download buttons for each export format.
4.1 Map layers
Toggleable via the map's layer control:
Route — the polyline plus a circle marker at every waypoint.
Wind arrows — small pennants at each waypoint showing wind direction (from) and speed (label at the arrow's tail).
Current arrows — slimmer pennants in a dark-blue colour, placed between consecutive waypoints.
Seamarks — nautical beacons and hazards overlaid from OpenSeaMap (on by default).
Land / water — base map tiles.
Hover or tap a waypoint circle for a tooltip listing wind, waves, current, course, heading and boat speed at that point.
4.2 Legend
A small legend in the top-right of the map explains the wind-arrow colour ramp and the marker shapes. On phones the legend collapses to a "Legend" pill that expands on tap.
4.3 Comfort score
Each waypoint is given a score from 0 to 100 combining wind, waves, heel angle and wave-to-hull angle. Totals are:
- 70 + — comfortable
- 40 – 69 — active
- below 40 — rough
The route's headline comfort score averages every waypoint.
4.4 Forecast-horizon warning
Weather forecasts reach up to five days out. If parts of your route extend past the last available forecast step, an amber banner shows: "N waypoints fell past the last forecast step." You still get a route for those waypoints, but the weather data beyond the horizon is a best-effort extrapolation — treat it cautiously.
4.5 Stopover markers
If your route has stopovers they appear as yellow Stop markers on the map; the route polyline continues through each without visual interruption.
4.6 Downloadable exports
Interactive HTML map — the file you're viewing in the browser; save it to keep an offline copy.
KML — open in Google Earth or most chart-plotter apps.
GPX — the standard sailing waypoint format; supported by practically every chart-plotter.
YAML — the full waypoint list with wind / wave / current at each step, in a human-readable plain-text format.
Offline HTML — a standalone map file that works with no internet connection. Useful at sea without signal.
5. Route history
The My Routes tab lists every route you've computed, most recent first, with a status badge:
- Complete — finished successfully; click to reopen the map.
- Running — still computing.
- Failed — something went wrong (credits were automatically refunded).
Click any completed route to reopen it in the result card — the map, the exports, and the weather overlays are all still there. Nothing expires.
6. Map picker — details
Opening Pick on map shows the Leaflet map used for visual pin-dropping. A few nuances:
Click ordering is strict: empty start, then empty end, then new stopovers, up to 5. Clicks never overwrite a filled slot.
The live cursor coordinate in the top-right updates as you move the mouse, in the format 48.381 N, 4.486 W.
Dragging a pin writes the new coordinates back into the text field and the hidden fields your submit uses.
Pins dropped on land — even inside a port you might consider "close enough" — get a red outline and a hover tooltip reading "On land — drag to water." You can still submit; the router will attempt to snap to the nearest sea point, but the result may not be what you want.
Clear map pins removes only the pins you created by clicking — text entries you typed are preserved.
The picker is an alternative to typing. The classic input path (harbour name or GPS paste) keeps working exactly as before; you can mix the two.
7. Credits
7.1 How many credits a route costs
A single-leg route (departure → arrival) costs 1 credit.
A multi-leg route (departure → N stopovers → arrival) costs N + 1 credits.
For example: Brest → La Rochelle → Bilbao = 2 stopovers = 3 credits.
7.2 Automatic refund
If the solver fails — a leg with no findable route, waypoints outside forecast coverage, invalid input — the credits deducted for that route are refunded automatically and the failure banner shows how many credits were returned.
7.3 How to get more credits
Every verified account starts with 50 free credits on signup. Additional credit packs and a subscription tier are in the pipeline but not yet live. In the meantime, the donation link helps keep the service free for everyone.
8. Showcase & Regattas
Two curated sets of pre-computed routes available to anyone:
Showcase (landing page): eight ongoing passages chosen to cover different regions (English Channel, Bay of Biscay, trans-Atlantic corridors, Caribbean, Mediterranean, Pacific, Southeast Asia) and different boat types.
Regattas (/regattas.html): a smaller set of iconic offshore races (Fastnet, Kiel Week → Warnemünde). Each one is a weather-routing study against the latest forecast — it is not a race entry, just a "what would this look like if I left now?" simulation.
Both sets are recomputed every few hours against fresh weather.
9. Submitting a missing harbour
If the port you're looking for isn't in the autocomplete dropdown:
Start typing the name.
When results are sparse, an ＋ Add "X" as a new port row appears at the bottom of the dropdown.
Click it, fill in the name, latitude, longitude and an optional note, and submit.
The entry is queued for curator review. Once approved, it becomes visible in everyone's autocomplete.
You can only submit if you're verified (avoids spam).
10. Account
Your header shows your email and current credit balance. The Account tab (or the right-aligned tab when you're logged in) lets you:
Log out.
See your verification status.
Access the donation link.
No public profile, no data sold. Your email is used only for verification, password reset, and occasional service-status notices — never for marketing.
11. On mobile
Everything works on a phone. A few accommodations:
The map legend is collapsed by default and opens on tap.
The layer toolbar moves to a footer bar under the map (on desktop Leaflet's own control is used instead).
Weather arrows thin out at low zoom so the map stays readable.
The map picker is the same single tool — Pick on map opens a full-width Leaflet map you can pinch-zoom, tap-drop and drag.
12. Safety disclaimer
Sailing Router is a planning aid. It is not a navigation system. It does not replace:
An up-to-date, paper or vector chart of the area you intend to sail.
Your own assessment of wind, sea and visibility on the day.
A backup plan, functioning safety gear and correctly-filed passage information.
Your judgement as skipper.
Weather forecasts — even the best ones — can be wrong. Currents near shore can differ significantly from the model. Tidal predictions are approximate. Always verify against a second source and adjust as conditions evolve.
Sailing Router is offered free, without warranty. You sail at your own risk.
13. Contact
Issues, feature requests, harbour corrections, or simply to say hello — use the contact form. Every message goes straight to the maintainer; your email is used only to reply.