Invisible Islands

About 500,000 islands have been mapped as areas, but up to 20,000 of them do not show up on the map because the mapper forgot to make them an ‘inner’ of the surrounding water body. (There are exceptions but this seems to be a common reason.)

This isn’t specific to one renderer, it affects all the maps on

(Occasionally the islands do render, because they have another tag that renders, such as natural=wood, but semantically that doesn’t make a difference: the trees aren’t in the water, else it wouldn’t be an island. So I suggest changing it anyway.)

I’ve made a MapRoulette challenge so we can fix these together. It’s a big task - 19,287 islands - so I can’t do it alone!

I suggest carefully reviewing each change - for example, you could take this as an opportunity to verify that it really is an island, and update its geometry.

Feedback is welcome, and the challenge is hidden in case there are comments, objections, or suggestions for alternative solutions to the problem.

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