Superseded Bench Mark Sheet for 8720686, FORT MATANZAS FL

Present Epoch

Printable version

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
Datums Page                                                        Page  1 of  6

                                                   PUBLICATION DATE:  10/15/1987
Station ID: 8720686                                SUPERCEDED DATE:   04/21/2003
Name:       FORT MATANZAS, MATANZAS RIVER                     
            FLORIDA
NOAA Chart: 11486                                  Latitude:         29° 42.9' N
USGS Quad:  MANTANZAS                              Longitude:        81° 14.1' W


To reach the tidal bench marks from Marineland, proceed 3.5 miles (5.6 km) NNW
on State Highway A1A to the Fort Matanzas State Park entrance, then west to Fort
Matanzas Visitors Center.  The bench marks are located within the park.  The
tide gage and staff were located on the Fort Matanzas National Monument pier.


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


                 PRIMARY BENCH MARK STAMPING:  1 1974

MONUMENTATION:           Survey Disk                               VM#:     5232
AGENCY:                                                            PID#:  AQ1557
SETTING CLASSIFICATION:  Rock Wall


The bench mark is set flush in the top center of a coquina fence wall at the SE
corner of a garden box, 45 feet (14 m) north of the north face of the Visitors
Center building, 15 feet (4.6 m) south of the SE corner of a garage, and 1.5
feet (0.5 m) below and 1.0 foot (0.3 m) west of the coquina wall.



                         BENCH MARK STAMPING:  Q 321 1970

MONUMENTATION:           Survey Disk                               VM#:     5231
AGENCY:                                                            PID#:  AQ0448
SETTING CLASSIFICATION:  Concrete Monument


The bench mark is set in the top of a concrete monument at the entrance road
leading west to Fort Matanzas, 154 feet (47 m) north of the centerline of the
entrance road, 45 feet (14 m) west of the centerline of State Highway A1A, 42
feet (13 m) south of the centerline of a private road leading west, 2 feet (0.6
m) south of a utility pole, 2 feet (0.6 m) north of a witness post, and at
ground level.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  2 of  6

                                                   PUBLICATION DATE:  10/15/1987
Station ID: 8720686                                SUPERCEDED DATE:   04/21/2003
Name:       FORT MATANZAS, MATANZAS RIVER                     
            FLORIDA
NOAA Chart: 11486                                  Latitude:         29° 42.9' N
USGS Quad:  MANTANZAS                              Longitude:        81° 14.1' W


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


                         BENCH MARK STAMPING:  2 1974

MONUMENTATION:           Survey Disk                               VM#:     5233
AGENCY:                                                            PID#:  AQ1556
SETTING CLASSIFICATION:  Rock Retaining Wall


The bench mark is set flush in the top center of a coquina retaining wall near
the tunnel through the Visitors Center building, 10 feet (3.0 m) SE of the
center of the east side of the tunnel, 1 foot (0.3 m) east of the easternmost
face of the building, and 5 feet (1.5 m) above sidewalk level.



                         BENCH MARK STAMPING:  3 1974

MONUMENTATION:           Survey Disk                               VM#:     5234
AGENCY:                                                            PID#:  AQ1555
SETTING CLASSIFICATION:  Rock Retaining Wall


The bench mark is set flush in the top center at the west end of the long
coquina culvert near the center of the north side of the park area circled by
the drive, 250 feet (76 m) east of the Visitors Center building, and 27 feet (8
m) south of and 1 foot (0.03 m) below the centerline of the south part of the
drive.



                         BENCH MARK STAMPING:  G

MONUMENTATION:           Survey Disk                               VM#:     5235
AGENCY:                                                            PID:         
SETTING CLASSIFICATION:  Concrete Monument


The bench mark is set flush in the top of a concrete monument on the east bank
of Matanzas River, 0.16 mile (0.26 km) north of the park office, 800 feet   
(244 m) east of Fort Matanzas on Rattlesnake Island, 500 feet (152 m) NNW of
Bench Mark H, 10 feet (3 m) east of the shoreline, and 0.3 foot (0.1 m) above
ground level.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  3 of  6

                                                   PUBLICATION DATE:  10/15/1987
Station ID: 8720686                                SUPERCEDED DATE:   04/21/2003
Name:       FORT MATANZAS, MATANZAS RIVER                     
            FLORIDA
NOAA Chart: 11486                                  Latitude:         29° 42.9' N
USGS Quad:  MANTANZAS                              Longitude:        81° 14.1' W


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


                         BENCH MARK STAMPING:  H

MONUMENTATION:           Survey Disk                               VM#:     5236
AGENCY:                                                            PID:         
SETTING CLASSIFICATION:  Concrete Monument


The bench mark is set flush in the top of a concrete monument on the east bank
of Matanzas River, 0.09 mile (0.14 km) north of the park office, 18 feet (5 m)
east of the shoreline, 9.0 feet (2.7 m) west of the dirt drive along the east
shore of the river, and 0.3 foot (0.1 m) above ground level.



                         BENCH MARK STAMPING:  P 321

MONUMENTATION:           Survey Disk                               VM#:     5237
AGENCY:                                                            PID#:  AQ0449
SETTING CLASSIFICATION:  Concrete Bridge Abutment


The bench mark is set on the top of the west end of the north concrete abutment
of the highway bridge over Matanzas Inlet, 20.5 feet (6.2 m) west of the
centerline of the highway,and 1 foot (0.3 m) above highway level.



                         BENCH MARK STAMPING:  NO STAMPING 1

MONUMENTATION:           Survey Disk                               VM#:     5238
AGENCY:                                                            PID:         
SETTING CLASSIFICATION:  Concrete Monument


The bench mark is set in a concrete monument on the western shore of Matanzas
River, 50 feet (15 m) NW of the NW corner of Fort Matanzas, 25 feet (8 m) SE of
the dock on the west side of Matanzas River, 2.0 feet (0.6 m) SW of the
shoreline, and at ground level.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  4 of  6

                                                   PUBLICATION DATE:  10/15/1987
Station ID: 8720686                                SUPERCEDED DATE:   04/21/2003
Name:       FORT MATANZAS, MATANZAS RIVER                     
            FLORIDA
NOAA Chart: 11486                                  Latitude:         29° 42.9' N
USGS Quad:  MANTANZAS                              Longitude:        81° 14.1' W


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


                         BENCH MARK STAMPING:  PL 7 E

MONUMENTATION:           Survey Disk                               VM#:     5239
AGENCY:                                                            PID:         
SETTING CLASSIFICATION:  Galvanized Steel Rod


The bench mark is 50 feet (15 m) SSE of the east end of the jetty north of the
concrete dock at the park office, and 15 feet (5 m) NNW of the boat launch north
of the park office.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  5 of  6

                                                   PUBLICATION DATE:  10/15/1987
Station ID: 8720686                                SUPERCEDED DATE:   04/21/2003
Name:       FORT MATANZAS, MATANZAS RIVER                     
            FLORIDA
NOAA Chart: 11486                                  Latitude:         29° 42.9' N
USGS Quad:  MANTANZAS                              Longitude:        81° 14.1' W


                            T I D A L   D A T U M S 


Tidal datums at FORT MATANZAS, MATANZAS RIVER based on:

     LENGTH OF SERIES:      11 MONTHS
     TIME PERIOD:           FEBRUARY-DECEMEBER,1974
     TIDAL EPOCH:           1960-1978
     CONTROL TIDE STATION:  8720220 MAYPORT


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

     HIGHEST OBSERVED WATER LEVEL (10/06/1974)         =   6.90
     MEAN HIGHER HIGH WATER                     MHHW   =   4.41
     MEAN HIGH WATER                            MHW    =   4.11
     MEAN TIDE LEVEL                            MTL    =   2.16
   * NATIONAL GEODETIC VERTICAL DATUM           NGVD29 =   1.85
     MEAN LOW WATER                             MLW    =   0.20
     MEAN LOWER LOW WATER                       MLLW   =   0.00
     LOWEST  OBSERVED WATER LEVEL (02/26/1975)         =  -1.49

   * NGVD is based on elevations published in Quad 290811, Feb 1974 and NOS
     levels of 1970. 
North American Vertical Datum (NAVD88)

Bench Mark Elevation Information                In FEET above:

     Stamping or Designation                    MLLW        MHW

     1 1974                                     13.56      9.45
     Q 321 1970                                 15.62     11.51
     2 1974                                     15.80     11.69
     3 1974                                      9.19      5.08
     G                                           5.43      1.32
     H                                           8.07      3.96
     P 321                                      16.04     11.93
     NO STAMPING 1                               4.48      0.37
     PL 7 E                                      7.91      3.80


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

                                                   PUBLICATION DATE:  10/15/1987
Station ID: 8720686                                SUPERCEDED DATE:   04/21/2003
Name:       FORT MATANZAS, MATANZAS RIVER                     
            FLORIDA
NOAA Chart: 11486                                  Latitude:         29° 42.9' N
USGS Quad:  MANTANZAS                              Longitude:        81° 14.1' 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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