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

                                                                                
Station ID: 8720503                         PUBLICATION DATE:  11/04/2020
Name:       RED BAY POINT, ST JOHNS RIVER                     
            FL
NOAA Chart: 11492                           Latitude:   29° 58.9' N (  29.98167)
USGS Quad:  GREEN COVE SPRINGS              Longitude:  81° 38.1' W ( -81.63417)


To reach the tide gauge from the junction of U.S. Highway 17 (Orange Avenue) and
State Road 16 (Ferris Street) in Green Cove Springs, go south on U.S. Highway 17
and State Road 16 for 0.97 km (0.6 mi) to the junction of State Road 16 East on
the left, turn left on State Road 16 and go east for 3.78 km (2.4 mi) to the
junction of Shands Pier Road on the left, turn left on Shands Pier Road and go
north for 0.56 km (0.4 mi) to the south end of Shands Pier, go northeast on
Shands Pier for 118.87 m (390.0 ft) where the tide gauge is located on the right
(southeast side of Pier). This location is about 59.44 m (195.0 ft) southwest of
the break in the pier. Bench marks are located along Shands Pier Road and State
Road 16.


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


                 PRIMARY BENCH MARK STAMPING:  0503 B 1995
                         DESIGNATION:          872 0503 B TIDAL

MONUMENTATION:           Flange-encased Rod                    VM#:        13490
AGENCY:                  National Ocean Service (NOS)          IDB PID#:  DE6867
SETTING CLASSIFICATION:  Stainless steel rod                   OPUS PID:        
LATITUDE:   29° 58.8' N (  29.97972)          LONGITUDE:  81° 38.1' W ( -81.63533)


The primary bench mark is a flange-encased rod located 96.01 m (315.0 ft) SSW of
the S end of the Shands Pier, 36.88 m (121.00 ft) NE of the approximate
centerline of Susan Drive (a paved road leading E), 22.43 m (73.6 ft) SE of the
approximate centerline of Shands Pier Road, 0.46 m (1.5 ft) NW of a 2.44 m (8.0
ft) tall fence and 0.43 m (1.40 ft) NW of a carsonite witness post.  The datum
point is recessed 9.14 cm (0.3 ft) below the level of the NGS logo cap, being
the top of a stainless steel rod driven to refusal at a depth of 21.12 m (69.3
ft) encased in a 5-inch logo cap flush with the ground. Note: The top of the
logo cap is missing.

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

                                                                                
Station ID: 8720503                         PUBLICATION DATE:  11/04/2020
Name:       RED BAY POINT, ST JOHNS RIVER                     
            FL
NOAA Chart: 11492                           Latitude:   29° 58.9' N (  29.98167)
USGS Quad:  GREEN COVE SPRINGS              Longitude:  81° 38.1' W ( -81.63417)


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


                         BENCH MARK STAMPING:  0503 C 1995
                         DESIGNATION:          872 0503 C TIDAL

MONUMENTATION:           Flange-encased Rod                    VM#:        13491
AGENCY:                  National Ocean Service (NOS)          IDB PID#:  DE6869
SETTING CLASSIFICATION:  Stainless steel rod                   OPUS PID#: DE6869
LATITUDE:   29° 58.7' N (  29.97828)          LONGITUDE:  81° 38.2' W ( -81.63678)


The bench mark is a flange-encased rod located near the intersection of Shands
Pier Road and Susan Drive, 10.00 m (32.8 ft) NW of the approximate centerline of
Shands Pier Road, 5.47 m (18.6 ft) NE of the approximate centerline of a dirt
road, 3.66 m (12.0 ft) NE of a metal gate, 0.37 m (1.2 ft) SE of a barbwire
fence and 0.30 m (1.0 ft) SE of a carsonite witness post.  The datum point is
recessed 9.14 cm (0.3 ft) below the level of the NGS logo cap, being the top of
a stainless steel rod driven to refusal at a depth of 21.95 m (72 ft) encased in
a 5-inch logo cap flush with the ground.



                         BENCH MARK STAMPING:  0503 D 1995
                         DESIGNATION:          872 0503 D TIDAL

MONUMENTATION:           Tidal Station disk                    VM#:        13492
AGENCY:                  National Ocean Service (NOS)          IDB PID#:  DE6870
SETTING CLASSIFICATION:  Concrete monument                     OPUS PID:        
LATITUDE:   29° 58.6' N (  29.97703)          LONGITUDE:  81° 38.3' W ( -81.63794)


The bench mark is a disk set in the top of a concrete monument flush with the
ground located at the intersection of State Road 16 and Shands Pier Road, 19.20
m (63.0 ft) N of the centerline of State Road 16, 11.16 m (36.6 ft) E of the
approximate centerline of Shands Pier Road and 0.76 m (2.5 ft) E of a wooden
power pole and carsonite witness post.

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

                                                                                
Station ID: 8720503                         PUBLICATION DATE:  11/04/2020
Name:       RED BAY POINT, ST JOHNS RIVER                     
            FL
NOAA Chart: 11492                           Latitude:   29° 58.9' N (  29.98167)
USGS Quad:  GREEN COVE SPRINGS              Longitude:  81° 38.1' W ( -81.63417)


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


                         BENCH MARK STAMPING:  0503 E 1995
                         DESIGNATION:          872 0503 E TIDAL

MONUMENTATION:           Tidal Station disk                    VM#:        13493
AGENCY:                  National Ocean Service (NOS)          IDB PID#:  DE6871
SETTING CLASSIFICATION:  Concrete monument                     OPUS PID:        
LATITUDE:   29° 58.6' N (  29.97694)          LONGITUDE:  81° 38.4' W ( -81.63919)


The bench mark is a disk set in the top of a concrete monument flush with the
ground located along State Road 16, 18.35 m (60.2 ft) S of the centerline of
State Road 16, 14.33 m (47.0 ft) E of the centerline of the entrance drive to
the John P. Hall, Sr. Nature Preserve (gate no. BC05), and 21.34 cm (0.7 ft) N
of a wooden fence line with a carsonite witness post.



                         BENCH MARK STAMPING:  0503 F 2004
                         DESIGNATION:          872 0503 F

MONUMENTATION:           Tidal Station disk                    VM#:        17775
AGENCY:                  FL Department of Environmental
                         Protection (FLDEP)                    IDB PID#:  DL5344
SETTING CLASSIFICATION:  Concrete sidewalk                     OPUS PID#: DL5344
LATITUDE:   29° 58.8' N (  29.98069)          LONGITUDE:  81° 38.1' W ( -81.63492)


The bench mark is a disk set in the top of a concrete sidewalk entrance of the
pier, 18.29 m (60.0 ft) NE of the security chain at the entrance to the pier,
3.05 m (10.0 ft) NW of the approximate centerline of the 6.10 m (20.0 ft) wooden
deck of the pier, 0.27 m (0.9 ft) NW of the wooden deck of the pier and 0.06 m
(0.3 ft) S of the 7-inch concrete curb.

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

                                                                                
Station ID: 8720503                         PUBLICATION DATE:  11/04/2020
Name:       RED BAY POINT, ST JOHNS RIVER                     
            FL
NOAA Chart: 11492                           Latitude:   29° 58.9' N (  29.98167)
USGS Quad:  GREEN COVE SPRINGS              Longitude:  81° 38.1' W ( -81.63417)


                            T I D A L   D A T U M S 


Tidal datums at RED BAY POINT, ST JOHNS RIVER based on:

     LENGTH OF SERIES:      3 YEARS
     TIME PERIOD:           11/03-10/05, 05/14-04/15
     TIDAL EPOCH:           1983-2001
     CONTROL TIDE STATION:  8720357 I-295 BRIDGE, WEST END, ST JOHNS RIVER


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

     HIGHEST OBSERVED WATER LEVEL (09/27/2004)         =  1.233
     MEAN HIGHER HIGH WATER                     MHHW   =  0.306
     MEAN HIGH WATER                            MHW    =  0.292
     North American Vertical Datum              NAVD88 =  0.219
     MEAN SEA LEVEL                             MSL    =  0.166
     MEAN TIDE LEVEL                            MTL    =  0.161
     MEAN LOW WATER                             MLW    =  0.029
     MEAN LOWER LOW WATER                       MLLW   =  0.000
     LOWEST  OBSERVED WATER LEVEL (04/14/2004)         = -0.367

North American Vertical Datum (NAVD88)

Bench Mark Elevation Information                In METERS above:

     Stamping or Designation                    MLLW        MHW

     0503 B 1995                                 1.490    1.198
     0503 C 1995                                 2.017    1.725
     0503 D 1995                                 2.578    2.286
     0503 E 1995                                 3.382    3.090
     0503 F 2004                                 1.499    1.207


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

                                                                                
Station ID: 8720503                         PUBLICATION DATE:  11/04/2020
Name:       RED BAY POINT, ST JOHNS RIVER                     
            FL
NOAA Chart: 11492                           Latitude:   29° 58.9' N (  29.98167)
USGS Quad:  GREEN COVE SPRINGS              Longitude:  81° 38.1' W ( -81.63417)


                             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.