NaCzarter Team
· Updated
Which apps to use on a boat trip in Masuria: the short version
On a boat trip in Masuria, it helps to have a weather app with storm alerts on your phone, for example IMGW Meteo or Windy, a route map that works offline, for example Mazury mapa żeglarska, and the numbers 601 100 100 and 984 saved along with the Ratunek app. Bring a paper map too, because coverage maps are only a rough guide and outside towns the signal can drop out.
We give prices and features based on the descriptions in the App Store and Google Play from autumn 2026, so before the 2027 season check whether the apps have been updated.
Weather and storms on your phone
The most important is the official IMGW Meteo app from IMGW (Poland's Institute of Meteorology and Water Management), released in March 2026 for iOS and Android. It is free and ad-free, and it shows a precipitation radar, a storm radar with a lightning map, IMGW weather warnings and the stations with the strongest wind and gusts. It can also send a notification when a storm is approaching your location, within a chosen radius of 50 to 200 km. You will find the same forecast and warnings in a browser at meteo.imgw.pl.
Windy is useful for wind and gusts, because it lets you compare several forecast models on one map and sends alerts about lightning nearby. The basic version is free, while a more detailed hourly forecast and unlimited alerts come with the paid Premium. Hour-by-hour wind up to five days ahead is also shown by the meteograms on meteo.pl, calculated by ICM at the University of Warsaw. These forecasts are also displayed in the Meteo ICM app.
Lightning maps such as burze.dzis.net or Blitzortung show storms that are already under way. They make it easy to see which way a front is moving, but they do not replace IMGW warnings. Blitzortung states plainly in its terms of use that its data is not meant for storm warnings. Before you leave port, also read our guide to weather and safety in Masuria.
Warning masts on the lakes
Along the route there are 17 masts of the warning light system, looked after since 2018 by Wody Polskie (the state water authority) in Białystok. The lights switch on automatically after an IMGW warning and are visible from 8 to 9 km away. 40 flashes per minute means caution, that is storms or strong wind are expected, and 90 flashes per minute is an alarm and a signal to look for a safe place immediately. The system works during the day and only in the navigation season. In the evening and outside the season, you are left with phone alerts and watching the sky.
Maps and navigation on your phone
| App | What it offers in Masuria | Price and platform |
|---|---|---|
| Mazury mapa żeglarska (ExpressMap) | offline route map, bridge clearances, power lines over the route, warning masts, depth contours, marinas, fuel stations for yachts | free, full coverage for a fee; iOS and Android |
| Żegluj | navigation, warnings about dangerous spots, ports and shops, sharing your position with the emergency services | free, lake depth maps from 29.99 to 39.99 PLN per lake; iOS and Android |
| Mazury Mini Locja | map, weather, signs, compass, text message with your position, emergency numbers | free; Android only, last updated in 2025 |
| Navionics Boating | offline maps, depths, route planning | annual subscription per region; iOS and Android |
| Mapy.com, Google Maps | getting to the port, shops, offline maps on land | free; iOS and Android |
For sailing the route itself, the Masurian apps give you the most, because they show things you won't find on road maps: bridge clearances, power lines and shallows. Navionics works offline, but before buying a region, check in the app whether it covers the Great Masurian Lakes. Download Google Maps or Mapy.com for offline use before you leave. Downloaded Google maps expire and refresh themselves when the phone connects to Wi-Fi.
A paper map needs no battery or signal, and the MOPR rescuers (the Masurian water rescue service) include it on their list of things to bring. Laminated sailing maps of the Great Masurian Lakes at a scale of 1:50,000 or 1:60,000, with depths and town plans, cost 25 to 40 PLN.
Don't look for the opening hours of the swing bridge in Giżycko or the Guzianka lock in apps. The bridge schedule is published by Zarząd Dróg Powiatowych w Giżycku (the district roads authority), and the lock hours by Wody Polskie in its navigation notices. We have collected last season's hours on our page about the swing bridge in Giżycko. In 2026 the Łuczański Canal was closed because of the construction of the bypass bridge, and yachts went through the Niegociński Canal, Tajty and the Piękna Góra Canal. Whether the disruption will continue in 2027 needs to be checked before your trip.
Signal and internet on the lakes
The mobile operator Play itself admits that in Masuria mobile internet fades away from the main roads and towns. The coverage maps of Plus, Orange, T-Mobile and Play are only a rough guide, and outside towns the signal can drop out. So download maps, a forecast for several days and your booking confirmation before you leave port.
Keep your phone in a waterproof case, as MOPR advises, and have a power bank on board. The 230 V sockets work on shore power or from an inverter, if the yacht has one, so on the water you usually charge your phone from a USB socket powered by the yacht's battery.
Emergency numbers and the Ratunek app
The water rescue number is 601 100 100, and it works throughout Poland. On the Great Masurian Lakes route and on Jeziorak, the emergency number 984 also works, and you can always call 112. MOPR is on duty around the clock. The Ratunek app connects you to 601 100 100 and, during the call, sends your exact position by text message. The iPhone version has not been updated since 2021, so before your trip check that it works on your phone. MOPR also advises that the whole crew should know the names of the lakes and landmarks along the route, so that everyone can say where they are. What to tell the rescuers once you are on the phone is covered in our cheat sheet on how to call for help in Masuria.
Frequently asked questions
Which weather app is best for Masuria? Start with IMGW Meteo, because it is free, shows official warnings and the storm radar, and also sends alerts about approaching storms. For wind and gusts, it is worth adding Windy or the meteograms from meteo.pl.
Is there an app with an offline sailing map of Masuria? Yes. Mazury mapa żeglarska works offline and shows bridge clearances, power lines and warning masts. Navionics also works offline, and Żegluj sells depth maps of individual lakes.
What do the flashing lights on the masts by the lakes mean? 40 flashes per minute is a caution about a storm or strong wind, and 90 flashes per minute is an alarm and a signal to head for a safe place immediately.
What is the emergency number in Masuria? The water rescue number is 601 100 100. On the Great Masurian Lakes route, 984 also works, and you can always call 112.
Is there mobile signal on the Masurian lakes? In towns and ports usually yes, but coverage maps are only a rough guide, and outside towns the signal can drop out. Download maps and the forecast before you set off, and keep your phone charged and in a waterproof case.
Cover photo: Ludwig Schneider / Wikimedia (CC BY-SA 3.0)
