I have written code to find islands (areas with place=island or =islet) within water bodies (areas with natural=water) where the island lies entirely within the water body, so the water body should be a multipolygon, when it isn't. This is for the challenge I described in https://community.openstreetmap.org/t/invisible-islands/108127.

Unfortunately the library that I used says the island (692587227) is “within” the river area with ID 854475224, which it isn’t: it’s between two river areas, so it's not inside either of them. So this island should never have appeared in my Maproulette challenge. I’ve reported this as a bug (https://github.com/clarisma/geodesk-py/issues/57), and once it gets fixed (the developers are usually really quick), I should be able to identify and exclude all affected cases from the MR challenge. I’ll also review those that have already been marked as “fixed” to make sure the edits are correct.