Nowadays relation are erased and now the maritime borders look bad at OSM as the area belonging to Spain does not appear on the map and "territorial waters" aren't in the relation of Spain border. The commentary on https://www.openstreetmap.org/changeset/49804213#map=8/35.315/-1.862 explains why the waters of Ceuta and Melilla are Spanish territory.
I discuss it here before touch anything to not start a war of editions.