All charts

Seamap

A nautical-themed map with depths, seamarks, and hazards.

Not for navigational use

This is a web map drawn in the style of a nautical chart, which makes it easy to mistake for one. It is not. Seamarks come from crowd-sourced OpenStreetMap data and may be missing, outdated, or wrong, and no hydrographic authority reviews any of it. Depths carry Seascape's caveats: they are not reduced to a chart datum, and do not account for tides or water level. Always consult official nautical charts for navigation.

Features

Depth, contours, and soundings

Shaded depth areas, contour lines, and spot soundings, merged from a mosaic of global open bathymetry.

Seamarks

Buoys, beacons, lights, landmarks, and harbours, with IALA buoyage defaults filled in so cardinal and lateral marks carry the right colours and topmarks.

Light sectors and characteristics

Sector lights drawn as coloured arcs with their boundary rays, labelled with standard characteristics like Fl(3)W.30s47m19M.

Traffic separation schemes

Separation zones, traffic lanes, and direction arrows where shipping is routed through busy water.

Rocks and obstructions

Rocks and obstructions marked individually, so isolated dangers stand out from the water around them.

Offshore infrastructure

Wind farms, platforms, and piles with the areas restricted around them, plus submarine cables and pipelines.

Sources

Seamap is an assembly. Each piece comes from a separate open project:

How to use

Point MapLibre GL, Mapbox GL, or any library that reads a MapLibre style at the published style URL. It carries the base map, bathymetry, and chart symbology together, so nothing else needs configuring:

https://tiles.openwaters.io/seamap/style.json

The seamark vector tiles are also available on their own at tiles.json, for composing into a style of your own. See the style package README for the builder API and the sprite sheet.

License

Tiles — the tiles, styles, and sprites served at tiles.openwaters.io/seamap are licensed CC BY 4.0: free for any use with the following attribution:

© Open Waters: Seamap <https://openwaters.io/charts/seamap>

They derive from OpenStreetMap data, © OpenStreetMap contributors (ODbL), and each source listed above carries its own license and attribution requirements. The style carries the full attribution list, which MapLibre's attribution control displays automatically.

Code — the pipeline and style are GPL-3.0, as is the chart symbol artwork. The project is a fork of prozessor13/seamap, and the code inherited from it remains MIT.