Bonasea

The chart

A chart-style map.

Depth bands, seamarks with their light characters, terrain contours, anchorages, fuel docks and hazards. No separate chart subscription, no per-region purchase.

On the water

What the map knows.

  • Seamarks and lights, with their characters. Lighthouses and buoys worldwide from OpenStreetMap, written the way a chart writes them: Fl(2)R.10s7m8M.
  • Terrain contours and hillshading. So you recognise an island by its silhouette before you recognise the bay.
  • Tides where they matter. Tide height at your arrival time, and the depth in the anchorage corrected for it.
  • Nearby, ashore. Restaurants, drinking water, shops, beaches, pharmacies, ATMs and ferries around the bay.
  • Map fixes shared between users. Open a narrow passage, close an area, or define a corridor the auto-route has to follow.
  • Offline when you need it. A map pack puts the region on the phone before you go, and the app shell and the tiles you have already seen stay there anyway.
  • Your units, not ours. Knots or km/h, feet or metres, gallons or litres.
The Bonasea map with a saved route, waypoints, anchorages, depth bands, soundings and seamarks.
Your route, with the chart underneath it.

Sources and layers

What is on the map.

Depth bands, contour lines and soundings show the sea floor, with a separate band for shallows that dry at low water. Depths come from regional models, so their accuracy varies by location. Check the chart alongside your sounder and official nautical charts.

The sources behind the map

Europe
EMODnet Bathymetry
United States and Caribbean
NOAA NCEI
Terrain and hillshading
Copernicus DEM
Tides
EOT20
Global depth background
GEBCO

Layers you can switch on

  • Favourite places, anchorages and mooring buoys
  • Fuel docks and services ashore
  • Depth bands, contours, soundings and drying shallows
  • Terrain contours, hillshading and seamarks
  • Rocks, wrecks, reefs and fish farms
  • Restricted areas, submarine cables and pipelines

Find what you need nearby

Look for a marina, fuel, drinking water or a restaurant around your current position or a point you choose on the chart. Results show the distance and direction.

Find nearest in Bonasea: a map and a list of nearby marinas, fuel, drinking water and restaurants with distances and directions.
Find services near your position or a point on the map.

Switch between Bonasea’s nautical map, OpenStreetMap with OpenSeaMap seamarks, and Esri satellite imagery. Each layer remembers your choice when you change the map background. Measure distance and bearing on the map, with travel time and ETA for your boat.

The map is a planning aid, not an official nautical chart.

See coverage

Find your day on the water.

Set your boat up once, and every route you care about gets a ten-day answer.

App StoreAvailable soonGoogle PlayAvailable soon

Start with Free when it lands. No card required.