VERTCRS["TGD2005",
    VDATUM["D_Tonga_Geodetic_Datum_2005"],
    CS[vertical,1],
        AXIS["ellipsoidal height (h)",up,
            LENGTHUNIT["metre",1]],
    USAGE[
        SCOPE["Not known."],
        AREA["Tonga - onshore and offshore."],
        BBOX[-25.68,-179.08,-14.14,-171.28]],
    ID["ESRI",115799]]