This Dept. of State Office of the Geographer World Water Body Limits data set has both detailed and simplified versions posted here, along with a centroid point file. All are intended as non-authoritative reference guides for the placement of water body names on maps. This data set includes 158 water bodies worldwide: all tidal water bodies exceeding both 250 kilometers in length and, at some point, 100 kilometers in width, plus some notable smaller ones.….Numerous smaller water bodies are not included.
In many locations, there are overlapping water body names (e.g. Golfo di Genova/ Ligurian Sea/ Mediterranean Sea) and the second field in this data set includes the more notable secondary/overlapping names. Also note that the shoreline of these water bodies is approximate and most small to medium sized islands are excluded. Names conform with the US Board on Geographic Names approved conventional and standard forms. While a member, the US has never and continues to not generally not conform to various International Hydrographic Office water body limits documents and drafts since the 1940’s. Relatively recently, 13 IHO states voted to add a fifth ocean, the “Southern Ocean”, south of 60 degrees South latitude; many authorities continue to consider the world as having just four oceans.
