Bench Mark Sheet for 8720625, Racy Point, St Johns River FL

Superseded Epoch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Small blue map location marker Unpublished bench mark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  9

                                                                                
Station ID: 8720625                         PUBLICATION DATE:  11/01/2011
Name:       RACY POINT, ST JOHNS RIVER                        
            FL
NOAA Chart: 11492                           Latitude:   29° 48.1' N (  29.80170)
USGS Quad:  RIVERDALE                       Longitude:  81° 32.9' W ( -81.54830)


To reach the tidal bench marks from the junction of County Road C-13 and State
Road 207 north of Hastings, proceed north on County Road C-13 for 11.3 km (7.0
mi) to the residence at No. 1635 County Road C-13.  The bench marks are in the
vicinity of several residences in the immediate area of Racy Point.  The tide
gage was located on a navigation structure about 79 m (260 ft) south of the
bulkhead along the St. Johns River.  The gage site can only be reached by boat
from the nearby Racy Point Park boat ramp.


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


                 PRIMARY BENCH MARK STAMPING:  0625 A 1995
                         DESIGNATION:          872 0625 A TIDAL

MONUMENTATION:           Flange-encased Rod                    VM#:        13494
AGENCY:                  National Ocean Service (NOS)          IDB PID#:        
SETTING CLASSIFICATION:  Stainless steel rod                   OPUS PID:        
LATITUDE:   29° 48.0' N (  29.80019)          LONGITUDE:  81° 33.0' W ( -81.54983)


The primary bench mark is a flange-encased rod located near the shoreline at
Racy Point, 91.44 m (300.0 ft) SW of the centerline of County Road C-13, 23.96 m
(78.6 ft) SSE of the SE corner of the residence No. 1635 (Franklin), 4.27 m
(14.0 ft) north of the sea wall, and 3.29 m (10.8 ft) NW of a 42-inch palm tree.
 The datum point is set 15.2 cm (0.5 ft) below the level of the NGS logo cap,
being the top of a stainless steel rod driven 19.81 m (65 ft) to refusal,
encased in a 5-inch NGS logo cap flush with the ground.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  2 of  9

                                                                                
Station ID: 8720625                         PUBLICATION DATE:  11/01/2011
Name:       RACY POINT, ST JOHNS RIVER                        
            FL
NOAA Chart: 11492                           Latitude:   29° 48.1' N (  29.80170)
USGS Quad:  RIVERDALE                       Longitude:  81° 32.9' W ( -81.54830)


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


                         BENCH MARK STAMPING:  0625 B 1995
                         DESIGNATION:          872 0625 B TIDAL

MONUMENTATION:           Flange-encased Rod                    VM#:        13495
AGENCY:                  National Ocean Service (NOS)          IDB PID#:        
SETTING CLASSIFICATION:  Stainless steel rod                   OPUS PID:        
LATITUDE:   29° 48.1' N (  29.80092)          LONGITUDE:  81° 33.0' W ( -81.54983)


The bench mark is a flange-encased rod located along the shoreline at Racy
Point, 91.44 m (300.0 ft)SW of the centerline of County Road C-13, 27.83 m (91.3
ft) SW of the SW corner of residence No. 1635 (Franklin), 23.77 m (78.0 ft)
south of the SE corner of the next house to the west (Floyd), and 5.12 m (16.8
ft) north of the sea wall.  The datum point is set 6.1 cm (0.2 ft) below the
level of the NGS logo cap, being the top of a stainless steel rod driven 19.50 m
(64 ft) to refusal, encased in a 5-inch NGS logo cap flush with the ground.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  3 of  9

                                                                                
Station ID: 8720625                         PUBLICATION DATE:  11/01/2011
Name:       RACY POINT, ST JOHNS RIVER                        
            FL
NOAA Chart: 11492                           Latitude:   29° 48.1' N (  29.80170)
USGS Quad:  RIVERDALE                       Longitude:  81° 32.9' W ( -81.54830)


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


                         BENCH MARK STAMPING:  STJ 8
                         DESIGNATION:          STJ 8

MONUMENTATION:           Bench Mark disk                       VM#:        13496
AGENCY:                  Florida Department of Transportation
                         (FLDT)                                IDB PID#:  AQ2627
SETTING CLASSIFICATION:  Bridge curbing                        OPUS PID:        
LATITUDE:   25° 47.9' N (  25.79831)          LONGITUDE:  81° 31.8' W ( -81.53000)


The bench mark is a disk set in the curb at the NE corner of the McCullough
Creek Bridge, located 9.3 km (5.8 mi) north along County Road C-13 from its
intersection with State Road 207 north of Hastings, 4.91 m (16.1 ft) NNE of the
centerline of County Road C-13, and 0.30 m (1.0 ft) above the road.  

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  4 of  9

                                                                                
Station ID: 8720625                         PUBLICATION DATE:  11/01/2011
Name:       RACY POINT, ST JOHNS RIVER                        
            FL
NOAA Chart: 11492                           Latitude:   29° 48.1' N (  29.80170)
USGS Quad:  RIVERDALE                       Longitude:  81° 32.9' W ( -81.54830)


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


                         BENCH MARK STAMPING:  STJ 9
                         DESIGNATION:          STJ 9

MONUMENTATION:           Bench Mark disk                       VM#:        13497
AGENCY:                  Florida Department of Transportation
                         (FLDT)                                IDB PID#:  AQ2628
SETTING CLASSIFICATION:  Bridge railing                        OPUS PID:        
LATITUDE:   29° 48.0' N (  29.79936)          LONGITUDE:  81° 32.4' W ( -81.53964)


The bench mark is a disk set in the bridge guardrail at the NE corner of the
Racy Point Bridge, located 10.16 km (6.35 mi) north along County Road C-13 from
its intersection with State Road 207 north of Hastings, 6.49 m (21.3 ft) NNE of
the centerline of County Road C-13, and 0.91 m (3.0 ft) above the road.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  5 of  9

                                                                                
Station ID: 8720625                         PUBLICATION DATE:  11/01/2011
Name:       RACY POINT, ST JOHNS RIVER                        
            FL
NOAA Chart: 11492                           Latitude:   29° 48.1' N (  29.80170)
USGS Quad:  RIVERDALE                       Longitude:  81° 32.9' W ( -81.54830)


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


                         BENCH MARK STAMPING:  RIVERDALE 2 1950
                         DESIGNATION:          RIVERDALE 2

MONUMENTATION:           Triangulation Station disk            VM#:        13498
AGENCY:                  US Coast and Geodetic Survey
                         (USC&GS)                              IDB PID#:  AQ2407
SETTING CLASSIFICATION:  Concrete monument                     OPUS PID:        
LATITUDE:   29° 48.1' N (  29.80192)          LONGITUDE:  81° 33.0' W ( -81.54981)


The bench mark is a disk set in top of a 8-inch square concrete monument located
on the line between the Floyds and Ellithorp properties at Racy Point, 46.63 m
(153.0 ft) NE of the garage on the Floyds' property, 9.45 m (31.0 ft) west of
the centerline of County Road C-13, 4.88 m (16.0 ft) east of a 16-inch oak tree,
0.61 m (2.0 ft) west of a 4-inch square concrete witness post standing 0.46 m
(1.5 ft) high, and 0.09 cm (0.3 ft) above ground level.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  6 of  9

                                                                                
Station ID: 8720625                         PUBLICATION DATE:  11/01/2011
Name:       RACY POINT, ST JOHNS RIVER                        
            FL
NOAA Chart: 11492                           Latitude:   29° 48.1' N (  29.80170)
USGS Quad:  RIVERDALE                       Longitude:  81° 32.9' W ( -81.54830)


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


                         BENCH MARK STAMPING:  RIVERDALE 1933 AZIMUTH
                         DESIGNATION:          RIVERDALE AZ MK

MONUMENTATION:           Azimuth Mark disk                     VM#:        13499
AGENCY:                  US Coast and Geodetic Survey
                         (USC&GS)                              IDB PID#:  AE6506
SETTING CLASSIFICATION:  Concrete monument                     OPUS PID:        
LATITUDE:   29° 48.0' N (  29.80072)          LONGITUDE:  81° 32.8' W ( -81.54703)


The bench mark is a disk set in top of a concrete monument near the shoreline at
Racy Point, 11.43 m (37.5 ft) south of the centerline of County Road C-13, 6.10
m (20.0 ft) north of the river bank, 0.61 m (2.0 ft) south of a 0.12 m (0.4 ft)
square concrete witness post standing 0.46 m (1.5 ft) high, and 0.15 m (0.5 ft)
above ground level.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  7 of  9

                                                                                
Station ID: 8720625                         PUBLICATION DATE:  11/01/2011
Name:       RACY POINT, ST JOHNS RIVER                        
            FL
NOAA Chart: 11492                           Latitude:   29° 48.1' N (  29.80170)
USGS Quad:  RIVERDALE                       Longitude:  81° 32.9' W ( -81.54830)


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


                         BENCH MARK STAMPING:  RIVERDALE RM 2 1933
                         DESIGNATION:          RIVERDALE RM 2

MONUMENTATION:           Reference Mark disk                   VM#:        13500
AGENCY:                  US Coast and Geodetic Survey
                         (USC&GS)                              IDB PID#:  AE6507
SETTING CLASSIFICATION:  Concrete monument                     OPUS PID:        
LATITUDE:   29° 48.1' N (  29.80161)          LONGITUDE:  81° 33.0' W ( -81.55003)


The bench mark is a disk set in top of a 8-inch square concrete monument located
on the line between the Floyds and Ellithorp properties at Racy Point, 79.55 m
(261.0 ft) SW of the centerline of County Road C-13, 46.63 m (153.0 ft) SSW of
bench mark RIVERDALE 2 1950, 0.46 m (1.5 ft) north of the NW corner of the
Floyds garage, and 0.15 m (0.5 ft) above ground level.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  8 of  9

                                                                                
Station ID: 8720625                         PUBLICATION DATE:  11/01/2011
Name:       RACY POINT, ST JOHNS RIVER                        
            FL
NOAA Chart: 11492                           Latitude:   29° 48.1' N (  29.80170)
USGS Quad:  RIVERDALE                       Longitude:  81° 32.9' W ( -81.54830)


                            T I D A L   D A T U M S 


Tidal datums at RACY POINT, ST JOHNS RIVER based on:

     LENGTH OF SERIES:      3 MONTHS
     TIME PERIOD:           May 2003 - July 2003
     TIDAL EPOCH:           1983-2001
     CONTROL TIDE STATION:  8720503 RED BAY POINT, ST JOHNS RIVER


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

     MEAN HIGHER HIGH WATER                     MHHW   =  0.384
     MEAN HIGH WATER                            MHW    =  0.369
     MEAN SEA LEVEL                             MSL    =  0.200
     MEAN TIDE LEVEL                            MTL    =  0.196
     North American Vertical Datum              NAVD88 =  0.189
     MEAN LOW WATER                             MLW    =  0.024
     MEAN LOWER LOW WATER                       MLLW   =  0.000

North American Vertical Datum (NAVD88)

Bench Mark Elevation Information                In METERS above:

     Stamping or Designation                    MLLW        MHW

     0625 A 1995                                 1.988    1.619
     0625 B 1995                                 1.314    0.945
     STJ 8                                       2.627    2.258
     STJ 9                                       3.260    2.891
     RIVERDALE 2 1950                            2.763    2.394
     RIVERDALE 1933 AZIMUTH                      3.453    3.084
     RIVERDALE RM 2 1933                         2.635    2.266


                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  9 of  9

                                                                                
Station ID: 8720625                         PUBLICATION DATE:  11/01/2011
Name:       RACY POINT, ST JOHNS RIVER                        
            FL
NOAA Chart: 11492                           Latitude:   29° 48.1' N (  29.80170)
USGS Quad:  RIVERDALE                       Longitude:  81° 32.9' W ( -81.54830)


                             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.

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