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Bench Mark Sheet for 9416841, Arena Cove CA

Superseded Epoch

Large map location marker Station Location
Small red map location marker Published bench mark
Small blue map location marker Unpublished bench mark

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  7

                                                                                
Station ID: 9416841                                PUBLICATION DATE:  12/08/2011
Name:       ARENA COVE, PACIFIC OCEAN                         
            CALIFORNIA
NOAA Chart: 18640                                  Latitude:         38° 54.8' N
USGS Quad:  POINT ARENA                            Longitude:       123° 42.5' W


To reach the tidal bench marks from Highway 1, turn west on Iversen Ave. and
continue 1.8 km (1.1 mi) to the waterfront.  The bench marks are located along
Port Road and Point Arena Creek in the vicinity.  The tide house is located at
the end of the Arena Cove Pier.


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


                 PRIMARY BENCH MARK STAMPING:  6 1945
                         DESIGNATION:          941 6841 TIDAL 6

MONUMENTATION:           Tidal Station disk                        VM#:     1005
AGENCY:                  US Coast and Geodetic Survey (USC&GS)     PID#:  JT9392
SETTING CLASSIFICATION:  Rock outcrop


The primary bench mark is a disk set in the top of a long narrow rock
outcropping located 152.40 m (500.0 ft) south of Arena Cove Pier along the
shoreline, 76.20 m (250.0 ft) south of a small stream emptying into the ocean,
and 8.84 m (29.0 ft) west of the base of a high cliff.



                         BENCH MARK STAMPING:  5 1945
                         DESIGNATION:          941 6841 TIDAL 5

MONUMENTATION:           Tidal Station disk                        VM#:     1006
AGENCY:                  US Coast and Geodetic Survey (USC&GS)     PID#:  JT9391
SETTING CLASSIFICATION:  Retaining wall


The bench mark is a disk set in the top of a retaining wall located east of the
boat house at Arena Cove Ocean Fresh Building, just west of the curve in the
retaining wall, 3.05 m (10.0 ft) east from the east face of the boat house, 1.33
m (4.375 ft) northeast of the bottom handrail post on the north side of the
stairway into the rear of the boat house, 0.55 m (1.8 ft) north of the south
edge of the wall, and 0.74 m (2.42 ft) above ground level.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  2 of  7

                                                                                
Station ID: 9416841                                PUBLICATION DATE:  12/08/2011
Name:       ARENA COVE, PACIFIC OCEAN                         
            CALIFORNIA
NOAA Chart: 18640                                  Latitude:         38° 54.8' N
USGS Quad:  POINT ARENA                            Longitude:       123° 42.5' W


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


                         BENCH MARK STAMPING:  6841 D 1977
                         DESIGNATION:          941 6841 D TIDAL

MONUMENTATION:           Tidal Station disk                        VM#:     1007
AGENCY:                  National Ocean Survey (NOS)               PID#:  JT9390
SETTING CLASSIFICATION:  Concrete step


The bench mark is a disk set in the second lowest concrete step located in the
stairway leading to the former Coast Guard Quarters, 0.24 km (0.15 mi) east of
the inshore end of the Arena Cove Pier, 30.48 m (100.0 ft) NNE of the centerline
of Port Street which leads to the Arena Cove Pier, 1.83 m (6.0 ft) west of the
west corner of a double doored wooden Arena Cove Lift Boat station, and 0.12 m
(0.4 ft) west of the eastern corner of the second step.



                         BENCH MARK STAMPING:  6841 F 1978
                         DESIGNATION:          941 6841 F TIDAL

MONUMENTATION:           Tidal Station disk                        VM#:     1009
AGENCY:                  National Ocean Survey (NOS)               PID#:  JT9393
SETTING CLASSIFICATION:  Rock outcrop


The bench mark is a disk set at the center of a 5 m x 3 m x 2 m (15 ft x 10 ft x
5 ft) high rock outcrop, located 198.12 m (650.0 ft) south of the Arena Cove
Pier along the shoreline, 46.94 m (154.0 ft) south of bench mark 941 6841 TIDAL
6, 18.29 m (60.0 ft) south of a 3 m (10 ft) high rock pinnacle, 9.14 m (30.0 ft)
west of the base of a high cliff.  

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  3 of  7

                                                                                
Station ID: 9416841                                PUBLICATION DATE:  12/08/2011
Name:       ARENA COVE, PACIFIC OCEAN                         
            CALIFORNIA
NOAA Chart: 18640                                  Latitude:         38° 54.8' N
USGS Quad:  POINT ARENA                            Longitude:       123° 42.5' W


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


                         BENCH MARK STAMPING:  6841 H 1979
                         DESIGNATION:          941 6841 H TIDAL

MONUMENTATION:           Tidal Station disk                        VM#:     1011
AGENCY:                  National Ocean Survey (NOS)               PID#:  JT9388
SETTING CLASSIFICATION:  Copper-clad steel rod


The bench mark is a disk set in the center of a niche located at the bottom of a
hill, 0.53 km (0.33 mi) east of the inshore end of the Arena Cove Pier, 92.05 m
(302.0 ft) east of a 3 m (10 ft) metal water line cover, 66.75 m (219.0 ft) west
of a 3 m (10 ft) metal water line cover, 18.29 m (60.0 ft) SE of the most
easterly of four large Eucalyptus trees, 9.14 m (30.0 ft) north of the
centerline of Port Road, and 0.46 m (1.5 ft) north of a 0.10 m x 0.10 m x 1.22 m
(0.3 ft x 0.3 ft x 4.0 ft) high white redwood witness post. The bench mark is
set 6 cm (0.2 ft) below grade, crimped to the top of a copper-clad steel rod
driven 2.4 m (7.9 ft) to refusal, and encased in a 4-inch PVC pipe.



                         BENCH MARK STAMPING:  6841 J 1979
                         DESIGNATION:          941 6841 J TIDAL

MONUMENTATION:           Tidal Station disk                        VM#:     1012
AGENCY:                  National Ocean Survey (NOS)               PID#:  JT9387
SETTING CLASSIFICATION:  Copper-clad steel rod


The bench mark is a disk set in a planter triangle located in between a split
driveway and Port Road at 240 Port Road, about 0.8 km (0.5 mi) east of the
inshore end of the Arena Cove pier, 11.83 m (38.8 ft) SW of a wood fence corner,
10.06 m (33.0 ft) north of the centerline of Port Road, 4.88 m (16.0 ft) south
of the "Y" in the driveway, and 0.61 m (2.0 ft) west of a 0.10 m x 0.10 m x 1.22
m (0.3 ft x 0.3 ft x 4.0 ft) high white painted redwood witness post. The bench
mark is set 46 cm (1.5 ft) below grade, crimped to the top of a copper-clad
steel rod driven 1.19 m (3.9 ft) to refusal, and encased in a 4-inch PVC pipe.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  4 of  7

                                                                                
Station ID: 9416841                                PUBLICATION DATE:  12/08/2011
Name:       ARENA COVE, PACIFIC OCEAN                         
            CALIFORNIA
NOAA Chart: 18640                                  Latitude:         38° 54.8' N
USGS Quad:  POINT ARENA                            Longitude:       123° 42.5' W


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


                         BENCH MARK STAMPING:  6841 N 1990
                         DESIGNATION:          941 6841 N

MONUMENTATION:           Tidal Station disk                        VM#:     1015
AGENCY:                  National Ocean Service (NOS)              PID:         
SETTING CLASSIFICATION:  Concrete bull rail


The bench mark is a disk set in the south concrete bullrail located at the Point
Arena Pier, 16.15 m (53.0 ft) east of the west end of the pier, 2.13 m (7.0 ft)
west of the base of a crane on the south side of the pier, and 0.15 m (0.5 ft)
north of the south face of the pier.



                         BENCH MARK STAMPING:  6841 P 1991
                         DESIGNATION:          941 6841 P

MONUMENTATION:           Tidal Station disk                        VM#:     3123
AGENCY:                  National Ocean Service (NOS)              PID:         
SETTING CLASSIFICATION:  Retaining wall


The bench mark is a disk set in a retaining wall located at the Arena Cove Pier,
2.35 m (7.7 ft) SW of the SW corner of the pier, 0.70 m (2.3 ft) SE of the SE
bull rail, 0.24 m (0.8 ft) north of the south edge of the wall, and 1.98 m (6.5
ft) below the pier.



                         BENCH MARK STAMPING:  6841 Q 1991
                         DESIGNATION:          941 6841 Q

MONUMENTATION:           Tidal Station disk                        VM#:     3124
AGENCY:                  National Ocean Service (NOS)              PID:         
SETTING CLASSIFICATION:  Concrete slab


The bench mark is a disk set in the NW corner of a 1.68 m x 1.37 m (5.5 ft x 4.5
ft) concrete service access panel located 2.74 m (9.0 ft) south of street lamp
pole No. 32 and 2.26 m (7.4 ft) east of a 2 m (7 ft) diameter circular sewer
access with a 4-inch goose neck vent pipe.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  5 of  7

                                                                                
Station ID: 9416841                                PUBLICATION DATE:  12/08/2011
Name:       ARENA COVE, PACIFIC OCEAN                         
            CALIFORNIA
NOAA Chart: 18640                                  Latitude:         38° 54.8' N
USGS Quad:  POINT ARENA                            Longitude:       123° 42.5' W


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


                         BENCH MARK STAMPING:  6841 S 2007
                         DESIGNATION:          941 6841 S

MONUMENTATION:           Flange-encased Rod                        VM#:    18485
AGENCY:                  National Ocean Service (NOS)              PID:         
SETTING CLASSIFICATION:  Stainless steel rod


The benchmark is a disk set in a concrete slab located 92.50 m (303.5 ft) east
of PG&E light pole #64, 8.50 m (27.9 ft) south of the centerline of Iverson Ave.
(Port Rd.), 3.13 m (10.3 ft) SSW from an 8" diameter wooden post with
reflectors, 0.50 m (1.6 ft) west from the east end of a stone wall, and 0.32 m
(1.0 ft) north of the stone wall.  The datum point of the mark is 10 cm (0.3 ft)
below ground level, being the top of a 9/16" steel rod driven 9.8 m (32.0 ft) to
refusal, encased in a 6" pvc pipe set in concrete with an aluminum access cover.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  6 of  7

                                                                                
Station ID: 9416841                                PUBLICATION DATE:  12/08/2011
Name:       ARENA COVE, PACIFIC OCEAN                         
            CALIFORNIA
NOAA Chart: 18640                                  Latitude:         38° 54.8' N
USGS Quad:  POINT ARENA                            Longitude:       123° 42.5' W


                            T I D A L   D A T U M S 


Tidal datums at ARENA COVE, PACIFIC OCEAN based on:

     LENGTH OF SERIES:      19 YEARS
     TIME PERIOD:           May 91 - April 08 + May 09 - April 11
     TIDAL EPOCH:           1983-2001
     CONTROL TIDE STATION:  9415020 POINT REYES, DRAKES BAY


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

     HIGHEST OBSERVED WATER LEVEL (02/06/1998)         =  2.639
     MEAN HIGHER HIGH WATER                     MHHW   =  1.787
     MEAN HIGH WATER                            MHW    =  1.583
     MEAN TIDE LEVEL                            MTL    =  0.968
     MEAN SEA LEVEL                             MSL    =  0.957
     MEAN LOW WATER                             MLW    =  0.352
     North American Vertical Datum              NAVD88 =  0.039
     MEAN LOWER LOW WATER                       MLLW   =  0.000
     LOWEST  OBSERVED WATER LEVEL (05/18/2003)         = -0.805

North American Vertical Datum (NAVD88)

Bench Mark Elevation Information                In METERS above:

     Stamping or Designation                    MLLW        MHW

     6 1945                                      2.782    1.199
     5 1945                                      6.236    4.653
     6841 D 1977                                 7.453    5.870
     6841 F 1978                                 2.991    1.408
     6841 H 1979                                 7.721    6.138
     6841 J 1979                                13.957   12.374
     6841 N 1990                                 8.699    7.116
     6841 P 1991                                 4.991    3.408
     6841 Q 1991                                 5.066    3.483
     6841 S 2007                                 6.440    4.857


                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  7 of  7

                                                                                
Station ID: 9416841                                PUBLICATION DATE:  12/08/2011
Name:       ARENA COVE, PACIFIC OCEAN                         
            CALIFORNIA
NOAA Chart: 18640                                  Latitude:         38° 54.8' N
USGS Quad:  POINT ARENA                            Longitude:       123° 42.5' 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.

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Products available at 9416841 Arena Cove, CA

Revised: 10/15/2013
NOAA / National Ocean Service
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