Way way/313697470 can't have natural=coastline tag. It can be placed only on sea/ocean shoreline and sea/ocean islands. I can't see from the bing imagery what is intended purpose for this way, so keeping it for now without any tags. Will delete it soon unless there will be some progress in reasonable time.

Please do not use tag natural=coastline outside of seas and oceans, abusing it breaks things.
I'm removing the tag natural=coastline right now, keeping the way untagged, because i cant figure out initial intention. Will delete the way in a few days unless i get some feedback.