Sailseer: every feature of the sailing app for passage planning

Sailseer is a free web app for harbour-to-harbour passage planning, with no account and no ads. It calculates the route for your boat and checks it against nine weather models, official warnings, tides, currents, and bridges and locks with their opening times. It is best suited to cruising sailors and charterers between Greenland, the Caribbean and the Indian Ocean.

What is Sailseer the best choice for?

Sailseer is the best choice when you are planning a specific route and want to know whether and when to cast off. Weather, tides, bridges, locks, harbours and formalities all come together in one calculation.

• Europe's coasts: North Sea and Baltic with Scandinavia and the Baltic states, the English Channel, Great Britain, Ireland, the Atlantic coast down to Agadir, Norway to Kirkenes, the Faroe Islands and Iceland (Germany, Denmark).
• Mediterranean, Black Sea and Red Sea including the Suez Canal, for example Croatia or Greece.
• Atlantic islands and the Arctic: Canaries, Madeira, Azores, Cape Verde, Bermuda, Greenland and Svalbard.
• Caribbean with Panama: 38 countries and territories from Trinidad to the Bahamas and Panama.
• U.S. East Coast: from the Florida Keys via the Intracoastal Waterway and Chesapeake Bay to Maine, with the warnings of the National Weather Service, NOAA buoys and tide gauges and NOAA's official charts (USA).
• Gulf of Mexico: from Florida's Big Bend via Mobile Bay and New Orleans with the locks on the Gulf Intracoastal Waterway to Texas, and on Mexico's Gulf coast from Tampico to Yucatán, with the National Weather Service offices, the NHC offshore forecast, the warnings of SMN and the HRRR model (USA, Mexico).
• Atlantic Canada: from the Bay of Fundy via Nova Scotia, the Bras d'Or Lakes and Prince Edward Island to Newfoundland and up the St. Lawrence River to Montréal, with the warnings and marine forecasts of Environment and Climate Change Canada, the HRDPS model, ECCC's coastal stations and the CBSA reporting sites (Canada, Saint Pierre and Miquelon, Guide).
• Indian Ocean: from the Seychelles, Madagascar and Mauritius via the Maldives and Sri Lanka to Phuket, Langkawi, Singapore and the Gulf of Thailand with Koh Samui.
• Pacific: from Baja California and the Sea of Cortez along the Pacific coast of Central America to Panama, to the Galápagos and to French Polynesia with Tahiti, the Tuamotus and the Marquesas, with the warnings and high seas forecasts of the National Hurricane Center and the local winds Tehuantepecer and Papagayo (Mexico).
• Lakes and inland waterways: 102 lakes such as Lake Constance, plus the Müritz with Mecklenburg and Berlin, the Göta Canal, Lake Mälaren, the Canal du Midi, the Caledonian Canal, the Shannon, the Norfolk Broads, the Masurian Lakes and Saimaa.
• Tidal waters and the Wadden Sea: tidal stream built into the passage time, time windows for tidal inlets and drying harbours.
• Routes with bridges and locks: from the Kiel Canal to the Panama Canal, including the wait until the next opening.
• Charter weeks: round trip by daily budget with reserve days and ports of refuge.
• More than one model: a consensus of nine models plus official warnings instead of a single forecast.
• No account: currently free and with no sign-up.

What does Sailseer do better than other sailing apps?

Sailseer works through the whole passage with your boat: weather, tides, bridges, harbours and rules in one plan. According to their product pages (as of September 2026), Windy, Windfinder, Windguru and PredictWind do not offer harbour depths, bridge opening times, firing times or tidal windows in the Wadden Sea (Sailing apps compared).

1. Consensus of nine weather models, including ICON, ECMWF IFS, the AI model AIFS and GFS: median, spread and agreement for every hour, plus uncertainty and gust probability from the 51 members of the ECMWF ensemble.
2. Best model from observations: yesterday's forecast is checked against the nearest stations; for each hour the model that has recently been most accurate counts, optionally for alerts too.
3. Official warnings across the whole area, from DWD, MeteoAlarm and MET Norway to the NHC in the Caribbean, filtered to the warning areas on your route, with warning alerts by email and push. Where a country has no retrievable warning source, the page says so explicitly.
4. Marine forecasts for each route from DWD, Met Office, Météo-France, MET Norway, AEMET, DMI and other services, filtered to the sea areas you pass through.
5. Bridges and locks built into the route: opening times from ELWIS, EuRIS (around 500 structures in the Netherlands, Belgium and France), Rijkswaterstaat FIS and the operators, including closures. The plan waits for the next opening and avoids fixed bridges that are too low for your mast.
6. Harbour info pages: around 8,800, with water depth checked against your draught, berths and 16 services from diesel to chandlery.
7. Tidal stream in speed over ground: against too strong a stream, the plan waits for the turn of the tide.
8. Tidal windows in the Wadden Sea: from EMODnet channel depths, when a tidal inlet or drying harbour is navigable.
9. Firing ranges with times from ELWIS and Niord: if an area is closed at the time you pass, the route goes around it; no route leads through areas where navigation is prohibited.
10. Traffic separation schemes with the crossing angle under COLREGs Rule 10.
11. Formalities by country: clearance, customs, Schengen, papers, fees such as the tourist tax in Croatia, permits and travel advice from the German Federal Foreign Office.
12. Tacks with your polar: your boat's pointing angle, leeway of 5 to 10 degrees and tacking loss, with no tack across land or water that is too shallow.
13. Comfort on your course: pitching, rolling and yawing in four levels from calm to rough.
14. Best departure within the next 120 hours and a sailing window alert as soon as a window of 55, 70 or 80 points opens (Weather window).
15. Float plan: if there is no “Arrived” after the ETA and a grace period, up to three shore contacts receive an email with the last position and emergency numbers.
16. Anchorages with shelter for each wind direction, a night check against the wind of the next 14 hours, and an anchor watch.
17. Boat instruments in the app via NMEA 0183, NMEA 2000 and Signal K.
18. GPX and GRIB: GPX 1.1 for Garmin, Raymarine and B&G, GRIB2 for OpenCPN, qtVlm and chart plotters.
19. Chart package of the visible area as MBTiles for OpenCPN.
20. Twelve languages for the site, alerts, push notifications and emails.
21. Free and private: currently with no account, no ads and no trackers; usage is counted by Sailseer's own server as anonymous daily totals.

All features at a glance

Forecast

• Nine weather models with a consensus at each point, plus AROME Antilles from Météo-France in the Caribbean.
• 10-day outlook for each harbour from ECMWF and GFS, shown as a trend from day six.
• Official marine forecasts for each route and point.
• Fog risk for every hour from dew point spread, wind and water temperature, including sea fog.
• Sailing recommendation including the local winds of the Mediterranean, from Mistral to Meltemi (Local winds).

Warnings

• MeteoAlarm with Europe's weather services, plus DWD, MET Norway, Met Éireann, IMO, DMI for Greenland, the services from Morocco to Egypt, NHC and NWS in the Caribbean and the services around the Indian Ocean.
• On inland lakes the DWD lake warning zones, for example Lake Constance and the Müritz, and the storm warning level on Lake Balaton.
• A clear notice when a warning source is currently down.

Tides and currents

• On the North Sea, BSH tide gauges with wind-driven surge; everywhere, the tidal curve from the Copernicus Marine ocean models with tidal range and water level.
• Moon with spring and neap times, wind against tide for each route (Tides and tidal streams).
• Currents from the Barents Sea to the Canaries, in the Mediterranean, the Black Sea and Red Sea, the Caribbean and the Indian Ocean.

Routing and tacking

• Route network built on EMODnet depth data, through buoyed channels, and along the centre line on rivers.
• Stopovers as in Google Maps, manual routes checked against land and depth, alternative routes.
• Multi-day trip, tidal window at each day's destination, ports of refuge and range from a harbour.
• Free sailing with local weather for each day, courses relative to the wind and the best window.
• Polar diagram for sailing boats with or without engine and for motorboats, with a factor from your GPX track (Sailing upwind).
• Fuel with engine hours, consumption, tank reserve and fuelling points.

Bridges and locks

• Opening times with public holidays, tidal rules and fees by boat length, for example on the Kiel Canal and the Panama Canal.
• Fixed bridges with clearance checked against your mast, on inland waters with the option “Mast lowered”.
• Waterways in Mecklenburg, Berlin and Brandenburg with 122 locks and 1,017 bridges, plus the Göta Canal, Lake Mälaren, the Caledonian, Crinan and Forth and Clyde canals, the Canal du Midi, the Shannon and Erne, the Norfolk Broads, the Masurian Lakes and Saimaa.
• Closures from the Notices to Mariners on the German coast.
• Dedicated pages for around 4,100 bridges and locks, such as the Kiel-Holtenau lock (Bridges and locks).

Harbours and anchorages

• Around 8,800 harbour pages (Harbours and cruising areas) with contact details, VHF, neighbouring harbours and a 10-day outlook.
• Harbour search, favourites marked with a star, shore-side supplies from OpenStreetMap, links to Navily and noforeignland.
• Around 460 webcams as links at harbours and along the route.
• Dedicated pages for each harbour, bridge, lock, country, lake and local wind in twelve languages.
• Anchorages from the western Baltic via the Caribbean to the Andaman Sea, and on inland lakes.

Restricted areas and rules

• Restricted, protected and hazard areas, with marine parks shown as notices.
• Country pages with formalities, cyclone season, local winds and harbours (Clearing in).

Maps and layers

• Weather maps from ICON, GFS, ECMWF and AROME: wind, gusts, pressure with isobars, rain, thunderstorm potential, visibility, water temperature and model spread, maximum values over 24 to 72 hours, animated particles and wind for the whole globe.
• Waves from the DWD's EWAM and GWAM models with height, swell, wind sea, period and direction of travel.
• DWD radar with nowcast and the European OPERA composite, satellite images every ten minutes, lightning.
• DWD surface charts with fronts.
• Chart with official content from Norway, Germany, the Netherlands and Latvia, buoys from eight more countries, OpenSeaMap, depths from EMODnet and UKHO wrecks.
• AIS with traffic density and live vessels including course, speed, type and destination.
• Around 28,100 lights with sectors; tapping a buoy shows its type, characteristic and how to pass it.

Alerts and briefing

• Wind alert for each harbour and sailing wind alert to your own specification (wind range, directions, gusts, waves, duration, daylight, days of the week) with a preview from five years of ERA5 data.
• Warning alert for every new official warning, checked every 15 minutes, and sailing window alert for each route.
• Morning briefing for each harbour with four parts of the day, warnings and tide.
• By email and push, with quiet hours from 22:00 to 07:00 for sailing wind and sailing window alerts.

Navigation mode and plotter

• Navigation mode like a chart plotter: full screen, course up, speed and course over ground with COG line, next waypoint, cross-track error, arrival times; also as free sailing with a track.
• Tacking aid with the next tack, off-route alarm, weather updated every 30 minutes from the boat's position.
• Track as GPX, import of routes from OpenCPN, Navionics and your plotter (GRIB and plotter).

Boat instruments

• Wind, depth, speed, GPS, AIS, engine, battery and tanks via NMEA 0183, NMEA 2000 (Yacht Devices, Actisense) and Signal K, in the app over Wi-Fi, Bluetooth and USB, in the browser over USB.
• True wind for the tacking aid, boat GPS, AIS with CPA alarm, shallow water alarm, your own polar.
• Route as WPL and RTE, optionally RMB, APB, XTE and BWC back to plotter and autopilot; all boat data stays on the device.

Safety

• Float plan with on-board link, view link with a map of the track, ETA reminder and all-clear message (Float plan).
• Thunderstorm and rain warning for the next hour with distance, direction and trend.
• Anchor watch with alarm for dragging, GPS loss and thunderstorms.
• Lights along legs sailed in the dark and at the entrance to your destination.

Statistics and validation

• Wind climate for each harbour from ERA5, day-by-day review with a verdict.
• Ranking of the models against observations with error, trend, direction and gusts (Weather models).
• Observations from official networks from DWD to NOAA, plus tide gauges, METAR and a good 150 private stations by the water.

Languages and privacy

• German, English, French, Spanish, Greek, Croatian, Turkish, Dutch, Italian, Polish, Czech and Danish.
• Boat, favourites and routes stay in your browser; you only need an email address for alerts and the float plan.
• Usage and error reports without position, which you can switch off in the cookie banner and via Global Privacy Control.
• Legal notice, privacy policy and contact form.

Offline and app

Sailseer runs in the browser on phone, tablet and laptop.

• Web app on your home screen, including on iPhone, with push notifications for alerts.
• Android app (testing via the Google group): calculates the harbour list, route, range, trip and GPX on the device without a connection, and reads boat instruments over the boat's Wi-Fi even without internet.
• Chart package as MBTiles for OpenCPN.
• Downloads for your plotter: route as GPX, weather as GRIB.

Plan your route on the map or read who is behind Sailseer.

Sailseer is a planning aid and not intended for navigation: official charts, marine forecasts and warnings take precedence.