EPSG:6359 — NGVD29 depth (ftUS)

VERTCRS[
    "NGVD29 depth (ftUS)",
    BASEVERTCRS[
        "NGVD29 height (ftUS)",
        VDATUM["National Geodetic Vertical Datum 1929",ID["EPSG",5102]],
        ID["EPSG",5702]
    ],
    DERIVINGCONVERSION[
        "Height <> Depth Conversion",
        METHOD["Height Depth Reversal",ID["EPSG",1068]],
        ID["EPSG",7812]
    ],
    CS[vertical,1,ID["EPSG",1043]],
    AXIS["Depth (D)",down],
    LENGTHUNIT["US survey foot",0.304800609601219,ID["EPSG",9003]],
    ID["EPSG",6359]
]

+vunits=us-ft +no_defs +type=crs

proj4.defs("EPSG:6359", "+vunits=us-ft +no_defs +type=crs");

{
  "type": "CoordinateReferenceSystem",
  "code": 6359,
  "name": "NGVD29 depth (ftUS)",
  "kind": "vertical",
  "area": "USA - CONUS - onshore",
  "unit": "US survey foot",
  "bbox": [
    24.41,
    -124.79,
    49.38,
    -66.91
  ],
  "proj4": "+vunits=us-ft +no_defs +type=crs"
}

INSERT INTO spatial_ref_sys (srid, auth_name, auth_srid, proj4text, srtext)
VALUES (6359, 'EPSG', 6359, '+vunits=us-ft +no_defs +type=crs', 'VERT_CS["NGVD29 depth (ftUS)",VERT_DATUM["National Geodetic Vertical Datum 1929",2005,AUTHORITY["EPSG","5102"]],UNIT["US survey foot",0.304800609601219,AUTHORITY["EPSG","9003"]],AXIS["Depth",DOWN],AUTHORITY["EPSG","6359"]]');

PROJECTION
  "+vunits=us-ft"
  "+no_defs"
  "+type=crs"
END

6359=VERT_CS["NGVD29 depth (ftUS)",VERT_DATUM["National Geodetic Vertical Datum 1929",2005,AUTHORITY["EPSG","5102"]],UNIT["US survey foot",0.304800609601219,AUTHORITY["EPSG","9003"]],AXIS["Depth",DOWN],AUTHORITY["EPSG","6359"]]