Bench mark positions only appear on the map if their coordinates in the CO-OPS database are at the precision of degrees/minutes/seconds/and tenths of seconds. If the coordinates are less precise, the mark will not appear.

Printable version

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
Datums Page                                                        Page  1 of  5

                                                                                
Station ID: 9414525                         PUBLICATION DATE:  04/29/2003
Name:       PALO ALTO YACHT HARBOR, S. F. BAY                 
            CA
NOAA Chart: 18651                           Latitude:   37° 27.5' N (  37.45830)
USGS Quad:  MOUNTAIN VIEW                   Longitude: 122°  6.3' W (-122.10500)


To reach the tidal bench marks fron the Embarcadero Road exit on U.S. Highway
101, proceed NE on Embarcadero Road for 1.9 km (1.2 mi) to Palo Alto Yacht
Harbor.  The bench marks are near the harbor.  The tide gage and staff were
located opposite Slip #13.


                         T I D A L   B E N C H   M A R K S

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  2 of  5

                                                                                
Station ID: 9414525                         PUBLICATION DATE:  04/29/2003
Name:       PALO ALTO YACHT HARBOR, S. F. BAY                 
            CA
NOAA Chart: 18651                           Latitude:   37° 27.5' N (  37.45830)
USGS Quad:  MOUNTAIN VIEW                   Longitude: 122°  6.3' W (-122.10500)


                         T I D A L   B E N C H   M A R K S


                 PRIMARY BENCH MARK STAMPING:  TIDAL 7 PA 1965
                         DESIGNATION:          TIDAL 7

MONUMENTATION:           Tidal Station disk                    VM#:         8327
AGENCY:                  US Coast and Geodetic Survey
                         (USC&GS)                              IDB PID#:  HT1274
SETTING CLASSIFICATION:  Concrete foundation                   OPUS PID#: HT1274
LATITUDE:   37° 27.4' N (  37.45670)          LONGITUDE: 122°  6.4' W (-122.10700)


The primary bench mark is a disk set on the rim at the SW corner of the
foundation for the fountain pool at the duck pond at the yacht harbor, on the
east side of the pond, 91 m (300 ft) north of the road, 15 m (50 ft) NNW of the
migratory bird sanctuary sign post, 4 m (12 ft) east of the pond rim. 

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  3 of  5

                                                                                
Station ID: 9414525                         PUBLICATION DATE:  04/29/2003
Name:       PALO ALTO YACHT HARBOR, S. F. BAY                 
            CA
NOAA Chart: 18651                           Latitude:   37° 27.5' N (  37.45830)
USGS Quad:  MOUNTAIN VIEW                   Longitude: 122°  6.3' W (-122.10500)


                         T I D A L   B E N C H   M A R K S


                         BENCH MARK STAMPING:  TIDAL 8 PA 1965
                         DESIGNATION:          TIDAL 8

MONUMENTATION:           Tidal Station disk                    VM#:         8328
AGENCY:                  US Coast and Geodetic Survey
                         (USC&GS)                              IDB PID#:  HT1273
SETTING CLASSIFICATION:  Spit                                  OPUS PID:        
LATITUDE:   37° 27.4' N (  37.45670)          LONGITUDE: 122°  6.6' W (-122.11000)


The bench mark is a disk set in the rim of the duck pond at the yacht harbor, on
the north side of the pond and at the west end of the spit, 9 m (30 ft) east of
the terminus of a cyclone fence, 3.81 m (12.5 ft) east of a right angle change
in direction of the duck pond bulkhead, and 0.18 m (0.6 ft) from the end of the
spit.



                         BENCH MARK STAMPING:  4525 C 1976
                         DESIGNATION:          941 4525 C

MONUMENTATION:           Tidal Station disk                    VM#:         8330
AGENCY:                  National Ocean Survey (NOS)           IDB PID#:        
SETTING CLASSIFICATION:  Unspecified rod                       OPUS PID:        
LATITUDE:   37° 27.5' N (  37.45830)          LONGITUDE: 122°  6.3' W (-122.10500)


The bench mark is a disk located 43 m (140 ft) east of the harbormasters office
front door, 25 m (83 ft) north of north post of Gate B-2 of Palo Alto Yacht
Harbor, 21 m (70 ft) east of the centerline of the Palo Alto Yacht Harbor ramp
road, 2 m (6 ft) west of the outer edge of the sand banked sea wall on the west
side of Palo Alto Yacht Harbor, and 0.85 m (2.8 ft) north of power pole # 26Y
with witness post marker.  The bench mark is set at ground level, crimped to the
top of an unspecified rod driven 9.8 m (32 ft), and encased in a PVC pipe.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  4 of  5

                                                                                
Station ID: 9414525                         PUBLICATION DATE:  04/29/2003
Name:       PALO ALTO YACHT HARBOR, S. F. BAY                 
            CA
NOAA Chart: 18651                           Latitude:   37° 27.5' N (  37.45830)
USGS Quad:  MOUNTAIN VIEW                   Longitude: 122°  6.3' W (-122.10500)


                            T I D A L   D A T U M S 


Tidal datums at PALO ALTO YACHT HARBOR, S. F. BAY based on:

     LENGTH OF SERIES:      7 MONTHS
     TIME PERIOD:           June 1984 - December 1984
     TIDAL EPOCH:           1983-2001
     CONTROL TIDE STATION:  9414750 ALAMEDA, SAN FRANCISCO BAY


Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in METERS:

     MEAN HIGHER HIGH WATER                     MHHW   =  2.321
     MEAN HIGH WATER                            MHW    =  2.130
     MEAN TIDE LEVEL                            MTL    =  1.182
     MEAN SEA LEVEL                             MSL    =  1.149
     MEAN LOW WATER                             MLW    =  0.234
     MEAN LOWER LOW WATER                       MLLW   =  0.000

North American Vertical Datum (NAVD88)

Bench Mark Elevation Information                In METERS above:

     Stamping or Designation                    MLLW        MHW

     TIDAL 7 PA 1965                             2.307    0.177
     TIDAL 8 PA 1965                             2.048   -0.082
     4525 C 1976                                 2.940    0.810

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  5 of  5

                                                                                
Station ID: 9414525                         PUBLICATION DATE:  04/29/2003
Name:       PALO ALTO YACHT HARBOR, S. F. BAY                 
            CA
NOAA Chart: 18651                           Latitude:   37° 27.5' N (  37.45830)
USGS Quad:  MOUNTAIN VIEW                   Longitude: 122°  6.3' W (-122.10500)


                             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 NGS's Integrated Data Base (IDB PID)
provides geodetic datum based on traditionally leveled and bluebooked ties to
the National Spatial Reference System(NSRS) https://www.ngs.noaa.gov/datasheets/.
The NGS Online Positioning User Service (OPUS PID) provides geodetic datum based
on GPS position & tie it to the NSRS https://www.ngs.noaa.gov/OPUS/.

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.