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Station ID: 9414837 SUPERCEDED DATE: 04/21/2003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Station ID: 9414837 SUPERCEDED DATE: 04/21/2003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.