VERTCRS["Caspian depth",
    VDATUM["Caspian Sea"],
    CS[vertical,1],
        AXIS["depth (D)",down,
            LENGTHUNIT["metre",1]],
    USAGE[
        SCOPE["Hydrography and nautical charting."],
        AREA["Azerbaijan - offshore; Kazakhstan - offshore; Russian Federation - Caspian Sea; Turkmenistan - offshore."],
        BBOX[37.35,46.95,46.97,53.93]],
    ID["EPSG",5706]]