U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Datums Page Page 1 of 5
PUBLICATION DATE: 06/22/1992
Station ID: 9415009 SUPERCEDED DATE: 04/21/2003
Name: POINT SAN PEDRO, SAN PABLO BAY
CALIFORNIA
NOAA Chart: 18654 Latitude: 37° 59.4' N
USGS Quad: SAN QUENTIN Longitude: 122° 26.8' W
To reach the tidal bench marks from San Rafael High School, proceed east on
Point San Pedro Road for 3.4 miles (5.5 km) to a road on the south side marked
Basalt Rock Company, go down the company road, then under an overpass to a left
turn and then follow the road along the shore until it reaches a loading ramp on
the north side of a barge pier. The bench marks are on Basalt Rock Compay
property along the shore. The tide gauge and staff were on the Basalt Rock
Company pier near the boat ramp on San Pablo Strait.
T I D A L B E N C H M A R K S
PRIMARY BENCH MARK STAMPING: 5009 A 1979
MONUMENTATION: Survey Disk VM#: 11809
AGENCY: PID:
SETTING CLASSIFICATION: Retaining Foundation Wall
The primary bench mark is set flush in the north retaining wall of the
northernmost barge loading ramp, about 900 feet (274 m) north of a hopper
structure adjacent to a rock crusher, 60 feet (18 m) west of the pier running
parallel to the shore, 16 feet (5 m) north of the centerline of the ramp, 12
feet (4 m) NW of the west edge of a pivoting metal loading ramp, and 0.6 foot
(0.2 m) from the edge of the foundation wall.
BENCH MARK STAMPING: V 551 1956
MONUMENTATION: Survey Disk VM#: 11808
AGENCY: PID#: HT1035
SETTING CLASSIFICATION: Concrete Foundation
The bench mark is set flush in the NE corner of a foundation at the west end of
the south one of two ruins of old wooden piers, and east of the south one of two
old tin buildings along the shore.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 2 of 5
PUBLICATION DATE: 06/22/1992
Station ID: 9415009 SUPERCEDED DATE: 04/21/2003
Name: POINT SAN PEDRO, SAN PABLO BAY
CALIFORNIA
NOAA Chart: 18654 Latitude: 37° 59.4' N
USGS Quad: SAN QUENTIN Longitude: 122° 26.8' W
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 5009 B 1979
MONUMENTATION: Survey Disk VM#: 11810
AGENCY: PID:
SETTING CLASSIFICATION: Foundation Wall
The bench mark is set flush in the top of the north foundation wall for a
subsurface conveyor running between the crushed rock hopper to the west and a
barge loading dock to the east, about 300 feet (91 m) NNE of the rock crusher,
89 feet (27 m) NNW of the NW corner of the company office, 27 feet (8 m) west of
a cinder block structure leading to the barge dock, and 13 feet (4 m) west of
the centerline of a road running north/south along the shore.
BENCH MARK STAMPING: 5009 C 1979
MONUMENTATION: Survey Disk VM#: 11811
AGENCY: PID:
SETTING CLASSIFICATION: Concrete Foundation
The bench mark is set flush in the concrete foundation of the northernmost tin
building along the shore, in the SW corner of the east doorway on the north side
of the old fish plant building in a loading area extension of the main
foundation slab, 225 feet (69 m) SE of the south edge of the east concrete wall
forming a truck ramp for the nearby rock crusher, 46 feet (14 m) west of the NE
corner of the foundation, 9.5 feet (2.9 m) from the east of the loading area,
and 7.2 feet (2.2 m) from the north edge of the foundation.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 3 of 5
PUBLICATION DATE: 06/22/1992
Station ID: 9415009 SUPERCEDED DATE: 04/21/2003
Name: POINT SAN PEDRO, SAN PABLO BAY
CALIFORNIA
NOAA Chart: 18654 Latitude: 37° 59.4' N
USGS Quad: SAN QUENTIN Longitude: 122° 26.8' W
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 5009 D 1979
MONUMENTATION: Survey Disk VM#: 11812
AGENCY: PID:
SETTING CLASSIFICATION: Concrete Foundation
The bench mark is set flush in the north corner of a concrete foundation for an
employees locker building, about 100 feet (30 m) south of an old metal tank
adjacent to a group of tin buildings and a large gas storage tank to the east,
65 feet (20 m) SE of the NE corner of an asphalt-making plant, and 1.5 feet
(0.5 m) east of the north corner of the building.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 4 of 5
PUBLICATION DATE: 06/22/1992
Station ID: 9415009 SUPERCEDED DATE: 04/21/2003
Name: POINT SAN PEDRO, SAN PABLO BAY
CALIFORNIA
NOAA Chart: 18654 Latitude: 37° 59.4' N
USGS Quad: SAN QUENTIN Longitude: 122° 26.8' W
T I D A L D A T U M S
Tidal datums at POINT SAN PEDRO, SAN PABLO BAY based on:
LENGTH OF SERIES: 6 MONTHS
TIME PERIOD: MAY - OCTOBER 1980
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 (03/27/1979) = 7.07
MEAN HIGHER HIGH WATER MHHW = 5.86
MEAN HIGH WATER MHW = 5.28
MEAN TIDE LEVEL MTL = 3.16
MEAN LOW WATER MLW = 1.05
MEAN LOWER LOW WATER MLLW = 0.00
LOWEST OBSERVED WATER LEVEL (05/16/1980) = -1.36
North American Vertical Datum (NAVD88)
Bench Mark Elevation Information In FEET above:
Stamping or Designation MLLW MHW
5009 A 1979 18.08 12.80
V 551 1956 11.17 5.89
5009 B 1979 18.79 13.51
5009 C 1979 11.58 6.30
5009 D 1979 17.74 12.46
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 5 of 5
PUBLICATION DATE: 06/22/1992
Station ID: 9415009 SUPERCEDED DATE: 04/21/2003
Name: POINT SAN PEDRO, SAN PABLO BAY
CALIFORNIA
NOAA Chart: 18654 Latitude: 37° 59.4' N
USGS Quad: SAN QUENTIN Longitude: 122° 26.8' 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 (NAVD88).
NAVD88 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. NAVD88 replaces NGVD29 as the national
standard geodetic reference for heights. Bench mark elevations relative to
NAVD88 are available from NGS through the World Wide Web at
National Geodetic Survey.
NGVD29 is a fixed datum adopted as a national standard geodetic reference for
heights but is now considered superseded. NGVD29 is sometimes referred to as
Sea Level Datum of 1929 or as Mean Sea Level on some early issues of Geological
Survey Topographic Quads. NGVD29 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 NGVD29 are available from the National
Geodetic Survey (NGS) data base via the World Wide Web at
National Geodetic Survey.
NAVD88 and NGVD29 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 NAVD88 elevation is shown on the Elevations of Tidal Datums Table Referred
to MLLW only when two or more of the bench marks listed have NAVD88 elevations.
The NAVD88 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, NAVD88 bench mark elevations computed indirectly from the tidal
datums elevation table may differ slightly from NAVD88 elevations listed for
each bench mark in the NGS database.