I think one possible reason (and I’m not saying this is why some mappers do this) why the polygon-style of mapping large water areas is done is because this allows labeling of such areas in atlas-style maps where the water area is visible, but doesn’t contain the center node. Minh’s example map above showing a diagonal label for the Gulf of California also renders a label for the Pacific Ocean, but you can definitely agree that that patch of the Pacific wouldn’t contain any conceivable place=ocean/sea node named “Pacific Ocean” or even the “Northern Pacific Ocean”. If you render such an atlas-style map using OSM data clipped to the (maybe buffered) area covered by the map, you obviously can’t automatically render the “Pacific Ocean” label without the node but could do so if you have a polygon. I don’t know of any way to do these nicely labeled maps automatically unless you have polygons or you resign to semi-automated methods and manually add such sea/ocean labels.
1 Like