VERTCRS["IGN 1988 SM (GUADELOUPE / SAINT-MARTIN)",
    VDATUM["IGN 1988 SM (GUADELOUPE / SAINT-MARTIN)"],
    CS[vertical,1],
        AXIS["gravity-related height (H)",up,
            LENGTHUNIT["metre",1]],
    USAGE[
        SCOPE["LOCALE A CARACTERE LEGAL"],
        AREA["ILE DE SAINT-MARTIN (GUADELOUPE)"],
        BBOX[18,-63.2,18.2,-62.5]],
    ID["IGNF","GUAD88SM"]]