VERTCRS["Black Sea depth",
    VDATUM["Black Sea"],
    CS[vertical,1],
        AXIS["depth (D)",down,
            LENGTHUNIT["metre",1]],
    USAGE[
        SCOPE["Hydrography and nautical charting."],
        AREA["Georgia - onshore and offshore."],
        BBOX[41.04,38.97,43.59,46.72]],
    ID["EPSG",5336]]