U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Datums Page Page 1 of 4 PUBLICATION DATE: 09/22/1983 Station ID: 9414837 SUPERCEDED DATE: 04/21/2003 Name: POINT CHAUNCEY, SAN FANCISCO BAY CALIFORNIA NOAA Chart: 18649 Latitude: 37° 53.5' N USGS Quad: SAN QUENTIN Longitude: 122° 26.6' W To reach the tidal bench marks proceed north along U.S. Highway 101 through Sausalito, over Richardson Bay Bridge, right at clover leaf intersection to Route 131, left after crossing Northwestern Pacific railroad tracks, and then south along Paradise Drive to Point Chaunrey. The tide gage and staff were located on the inside of the L-shaped NOAA Southwest Marine Fisheries Pier. T I D A L B E N C H M A R K S PRIMARY BENCH MARK STAMPING: 11 1946 MONUMENTATION: Survey Disk VM#: 8442 AGENCY: PID#: HT1059 SETTING CLASSIFICATION: Concrete The bench mark is set in top of the concrete coping forming the door entrance to the machine and electric shop of the U.S. Naval Net Depot, at the south corner of the shop, 0.6 foot (0.1 m) SE of the SE face of the building, 0.3 foot (0.1 m) NE of projected SW face of the building, and 1.4 feet (0.4 m) above level of the door threshold. BENCH MARK STAMPING: 10 1937 MONUMENTATION: Survey Disk VM#: 8441 AGENCY: PID#: HT1060 SETTING CLASSIFICATION: Concrete The bench mark is set on a low narrow concrete shelf on the NE side of the gantry crane track support on the California Nautical School ground, 140 feet (42.7 m) SW of Bench Mark 11 1946, 8.3 feet (25 m) from the NW face of the dock, and 28.5 feet (8.7 m) from the north end of the support.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 2 of 4 PUBLICATION DATE: 09/22/1983 Station ID: 9414837 SUPERCEDED DATE: 04/21/2003 Name: POINT CHAUNCEY, SAN FANCISCO BAY CALIFORNIA NOAA Chart: 18649 Latitude: 37° 53.5' N USGS Quad: SAN QUENTIN Longitude: 122° 26.6' W T I D A L B E N C H M A R K S BENCH MARK STAMPING: 12 1946 MONUMENTATION: Survey Disk VM#: 8443 AGENCY: PID#: HT1061 SETTING CLASSIFICATION: Concrete The bench mark is set in the concrete floor of themain doorway entrance to the south warehouse at the US Naval Net Depot, 135 feet (41 m) SW of the gantry crane track support, 0.8 foot (0.2 m) NE of the steel door runner embeded in the concrete floor, and 0.7 foot (0.2 m) NW of the face of the large steel column forming the SE side of the doorway. BENCH MARK STAMPING: CO RD 1975 MONUMENTATION: Survey Disk VM#: 8444 AGENCY: PID: SETTING CLASSIFICATION: Concrete The bench mark is set horizontally in concrete 65 feet (20 m) east of a power pole, 27 feet (8.2 m) north of Bench Mark 10 1937, 0.5 foot (0.2 m) north of the NE corner of the concrete column at the northermost and of a large abandoned gantry crane track support and flush with the asphalt pavement. BENCH MARK STAMPING: N17 38-3/4 CH 21.56L ELEV 5.64 FT BELOW THIS PLATE MONUMENTATION: Survey Disk VM#: 8445 AGENCY: PID#: HT1062 SETTING CLASSIFICATION: Seawall The bench mark is set in the inner end of the L-shaped wooden wharf, inbeded in top of the concrete seawall, 330 feet (101 m) east of the administration building, 7.5 feet (2.3 m) NE of the SE corner of building N0 54, and 4.0 feet (1.2 m) south of the NW corner of the wharf.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 3 of 4 PUBLICATION DATE: 09/22/1983 Station ID: 9414837 SUPERCEDED DATE: 04/21/2003 Name: POINT CHAUNCEY, SAN FANCISCO BAY CALIFORNIA NOAA Chart: 18649 Latitude: 37° 53.5' N USGS Quad: SAN QUENTIN Longitude: 122° 26.6' W T I D A L D A T U M S Tidal datums at POINT CHAUNCEY, SAN FANCISCO BAY based on: LENGTH OF SERIES: 9 MONTHS TIME PERIOD: FEBRUARY - OCTOBER 1977 TIDAL EPOCH: 1960-1978 CONTROL TIDE STATION: 9414290 SAN FRANCISCO Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in FEET: HIGHEST OBSERVED WATER LEVEL (06/29/1977) = 6.99 MEAN HIGHER HIGH WATER (MHHW) = 5.72 MEAN HIGH WATER (MHW) = 5.13 MEAN TIDE LEVEL (MTL) = 3.10 * NATIONAL GEODETIC VERTICAL DATUM-1929 (NGVD) = 2.57 MEAN LOW WATER (MLW) = 1.08 MEAN LOWER LOW WATER (MLLW) = 0.00 LOWEST OBSERVED WATER LEVEL (06/02/1977) = -2.00 * NGVD reference based on adjustment of 1956 and NOS levels of1977. National Geodetic Vertical Datum (NGVD 29) Bench Mark Elevation Information In FEET above: Stamping or Designation MLLW MHW 11 1946 15.47 10.34 10 1937 15.86 10.73 12 1946 16.59 11.46 CO RD 1975 13.03 7.90 N17 38-3/4 CH 21.56L ELEV 5.64 FT BELOW THIS PLATE 12.85 7.22
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 4 of 4 PUBLICATION DATE: 09/22/1983 Station ID: 9414837 SUPERCEDED DATE: 04/21/2003 Name: POINT CHAUNCEY, SAN FANCISCO BAY CALIFORNIA NOAA Chart: 18649 Latitude: 37° 53.5' N USGS Quad: SAN QUENTIN Longitude: 122° 26.6' W D E F I N I T I O N S Mean Sea Level (MSL) is a tidal datum determined over a 19-year National Tidal Datum Epoch. It pertains to local mean sea level and should not be confused with the fixed datums of North American Vertical Datum of 1988 (NAVD 88). NGVD 29 is a fixed datum adopted as a national standard geodetic reference for heights but is now considered superseded. NGVD 29 is sometimes referred to as Sea Level Datum of 1929 or as Mean Sea Level on some early issues of Geological Survey Topographic Quads. NGVD 29 was originally derived from a general adjustment of the first-order leveling networks of the U.S. and Canada after holding mean sea level observed at 26 long term tide stations as fixed. Numerous local and wide-spread adjustments have been made since establishment in 1929. Bench mark elevations relative to NGVD 29 are available from the National Geodetic Survey (NGS) data base via the World Wide Web at National Geodetic Survey. NAVD 88 is a fixed datum derived from a simultaneous, least squares, minimum constraint adjustment of Canadian/Mexican/United States leveling observations. Local mean sea level observed at Father Point/Rimouski, Canada was held fixed as the single initial constraint. NAVD 88 replaces NGVD 29 as the national standard geodetic reference for heights. Bench mark elevations relative to NAVD 88 are available from NGS through the World Wide Web at National Geodetic Survey. NGVD 29 and NAVD 88 are fixed geodetic datums whose elevation relationships to local MSL and other tidal datums may not be consistent from one location to another. The Vertical Mark Number (VM#) and PID# shown on the bench mark sheet are unique identifiers for bench marks in the tidal and geodetic databases, respectively. Each bench mark in either database has a single, unique VM# and/or PID# assigned. Where both VM# and PID# are indicated, both tidal and geodetic elevations are available for the bench mark listed. The NAVD 88 elevation is shown on the Elevations of Tidal Datums Table Referred to MLLW only when two or more of the bench marks listed have NAVD 88 elevations. The NAVD 88 elevation relationship shown in the table is derived from an average of several bench mark elevations relative to tide station datum. As a result of this averaging, NAVD 88 bench mark elevations computed indirectly from the tidal datums elevation table may differ slightly from NAVD 88 elevations listed for each bench mark in the NGS database.