creating a Place = island does not create land. It does however allow you to give the island a name and thus allowingpeople to search for it.
creaing a natural = coastline however does create land, bare in mind that
1: the direction of the way/line MUST be anti-clockwise as to not screw over the entire ocean
2: coastlines take longer to update in the view mode than other edits
Hope it helps, check the wiki as well, creating and changing coasts can create issues. Happy mapping!
Discussion
Comment from Liadrien on 29 September 2020 at 16:10
creating a Place = island does not create land. It does however allow you to give the island a name and thus allowingpeople to search for it.
creaing a natural = coastline however does create land, bare in mind that 1: the direction of the way/line MUST be anti-clockwise as to not screw over the entire ocean 2: coastlines take longer to update in the view mode than other edits
Hope it helps, check the wiki as well, creating and changing coasts can create issues. Happy mapping!
Comment from wangi on 29 September 2020 at 17:18
You DO NOT use natural=coastline for islands in an inland lake. You add them as “inner” members of the relation.
osm.wiki/Relation:multipolygon