I'm looking for a free high resolution map that clearly indicates the land and sea in the world. I need it to calculate distances over sea between ports. Additionally it should also include inland waterways and canals.

Does anybody know whether this data is freely available?

  • This is a question that might be better researched/asked at the Open Data Stack Exchange.
    – PolyGeo
    Commented Oct 6, 2016 at 6:40

3 Answers 3


One of the best sources for open-source vector and raster map data is Natural Earth. There is a variety of data available at large, medium and small scale. You would likely need the Ports dataset available from 1:10m Cultural Vectors and the Rivers, Lake Centerlines available from 1:50m Physical Vectors.

  • Thanks for your reply. The problem with the maps available at this site is that the information they contain is a value between 0 and 255 which I can not convert to a coding for land and sea. Also the rivers Lakes center lines do not contain the Suez and Panama canal. Thus it does not solve my problem. I tried this solution: but it does not work.
    – Jan-Pieter
    Commented May 18, 2015 at 11:18
  • You will have to provide more information as to why this data is not sufficient. This is one of the best data sources for map data. Indeed, it contains everything you need for your analysis.
    – Aaron
    Commented May 18, 2015 at 11:50
  • I could be missing something. However when I import this map (I chose the 'Cross Blended Hypso with Relief, Water, Drains, and Ocean Bottom' map, the values of the map are between all between 0 and 255. In the end I need a map with value 0 for all seas, rivers and canals and a 1 for every part that is land and ships can thus not sail. With this map I get for all places of the map values between 0 and 255. This coding I can not convert to the format I want. For example: there are places in the Atlantic that have the same value as places in Latin-America.
    – Jan-Pieter
    Commented May 18, 2015 at 12:05
  • In the end I solved it by using a shape file with all countries in the world, added the Suez and Panama Canal manually using QGIS and added the ice of the Artic and Antartica by using shape files as well. I did not include the rivers in the end.
    – Jan-Pieter
    Commented May 19, 2015 at 15:03
  • @user50690 Please consider adding your solution as an answer so we can consider this question resolved.
    – Aaron
    Commented May 19, 2015 at 15:06

After some trial and error the most practical solution turned out to be:

Use a shape file of all world countries, add the Suez and Panama canal manually using software like QGIS, add the ice of the arctic and Antarctica using shapefiles as well. This gives you a map of all the places a ship can go.

I left out the inland waterways in the end. However these could be included using the link provided by Aaron.


This is what has helped me in similar projects - free maps for all designers and mappers. It could be useful to you too

  • 1
    If you or Maria Tolsa have any connection to the maps that you are promoting here then you need to disclose that in every answer you mention it in.
    – PolyGeo
    Commented Oct 6, 2016 at 10:46

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