Looking for maps of the seas

Hello. I looking for the maps of the oceans, seas, bays, straits in OSM format. I've already found https://www.naturalearthdata.com/, but these maps are in shp format. I processed .shp in JOSM, changed xml structure of the files (due to the fact that Osmosis don't like JOSM processed .shp files), used Osmosis for converting osm to osm.pbf. But it didn`t work.

Do you have any simple solution for that?