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Bench Mark Sheet for 8729119, SHELL ISLAND, ST. ANDREWS BAY 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Superseded Epoch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Small blue map location marker Unpublished bench mark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  5

                                                                                
Station ID: 8729119                         PUBLICATION DATE:  11/13/2003
Name:       SHELL ISLAND, ST. ANDREW B.                       
            FL
NOAA Chart: 11391                           Latitude:   30°  5.7' N (  30.09500)
USGS Quad:  BEACON BEACH                    Longitude:  85° 41.1' W ( -85.68500)


To reach the tidal bench marks from the boat launch at St. Andrew State Park,
proceed SSE 6.3 km (3.9 mi) to about midpoint, on the NE shoreline and Captain
Andersons Shell Island Tours Pier on Shell Island.  The bench marks are located
along and the grassy sand dunes along the middle of Shell Island between St.
Andrew Bay and the Gulf of Mexico on a NW-SE line from the pier, and the gage
site and staff were located on the pier.


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


                 PRIMARY BENCH MARK STAMPING:  NO 3 1976
                         DESIGNATION:          872 9119 TIDAL 3

MONUMENTATION:           Tidal Station disk                    VM#:        10013
AGENCY:                  National Ocean Survey (NOS)           IDB PID#:  BE1354
SETTING CLASSIFICATION:  Copper-clad steel rod                 OPUS PID:        
LATITUDE:   30°  5.7' N (  30.09500)          LONGITUDE:  85° 41.1' W ( -85.68500)


The primary bench mark is a disk located on the SE edge of the low ground
between two ridges of grassy covered sand dunes, 1.58 m (5.2 ft) NW of a line of
three 3 m (10 ft) high piles, and 12 cm (0.4 ft) NNW of a witness post.  The
bench mark is set 6 cm (0.2 ft) below ground level, crimped to the top of a
copper-clad steel rod driven 12 m (40 ft) to refusal, and encased in a PVC pipe
and concrete kickblock.

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

                                                                                
Station ID: 8729119                         PUBLICATION DATE:  11/13/2003
Name:       SHELL ISLAND, ST. ANDREW B.                       
            FL
NOAA Chart: 11391                           Latitude:   30°  5.7' N (  30.09500)
USGS Quad:  BEACON BEACH                    Longitude:  85° 41.1' W ( -85.68500)


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


                         BENCH MARK STAMPING:  R114 BAY CO 1972
                         DESIGNATION:          R 114 FLDNR

MONUMENTATION:           Survey disk                           VM#:        10014
AGENCY:                  Florida Department of Natural Resources
                         (FLDNR)                               IDB PID#:  BE1353
SETTING CLASSIFICATION:  Concrete monument                     OPUS PID:        
LATITUDE:   30°  5.6' N (  30.09330)          LONGITUDE:  85° 41.1' W ( -85.68500)


The bench mark is a disk set into the top of a concrete monument on the grassy
ridge of sand dunes paralleling the bay, 183 m (600 ft) SSW of the bay, 177 m
(580 ft) NW of bench mark NO 3 1976, 107 m (350 ft) NNE of the Gulf of Mexico,
19.48 m (63.9 ft) NE of the NE corner of the beige cottage on the beach, and
6.37 m (20.9 ft) south of a water pump.

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

                                                                                
Station ID: 8729119                         PUBLICATION DATE:  11/13/2003
Name:       SHELL ISLAND, ST. ANDREW B.                       
            FL
NOAA Chart: 11391                           Latitude:   30°  5.7' N (  30.09500)
USGS Quad:  BEACON BEACH                    Longitude:  85° 41.1' W ( -85.68500)


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


                         BENCH MARK STAMPING:  R115 BAY CO 1972
                         DESIGNATION:          R 115 FLDNR

MONUMENTATION:           Survey disk                           VM#:        10015
AGENCY:                  Florida Department of Natural Resources
                         (FLDNR)                               IDB PID#:        
SETTING CLASSIFICATION:  Concrete monument                     OPUS PID:        
LATITUDE:   30°  5.6' N (  30.09330)          LONGITUDE:  85° 41.1' W ( -85.68500)


The bench mark is a disk set into the top of a concrete monument on a grassy
ridge of sand dunes paralleling the bay, 0.9 km (0.6 mi) ESE of bench mark R114
BAY CO 1972, 155 m (510 ft) SE of the SE inner corner of the pier on the bay,
149 m (490 ft) south of bench mark NO 1 1976, and 76.20 m (250.0 ft) north of
the Gulf of Mexico.

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

                                                                                
Station ID: 8729119                         PUBLICATION DATE:  11/13/2003
Name:       SHELL ISLAND, ST. ANDREW B.                       
            FL
NOAA Chart: 11391                           Latitude:   30°  5.7' N (  30.09500)
USGS Quad:  BEACON BEACH                    Longitude:  85° 41.1' W ( -85.68500)


                            T I D A L   D A T U M S 


Tidal datums at SHELL ISLAND, ST. ANDREW B. based on:

     LENGTH OF SERIES:      4 MONTHS
     TIME PERIOD:           November 1976 - February 1977
     TIDAL EPOCH:           1983-2001
     CONTROL TIDE STATION:  8729840 PENSACOLA, PENSACOLA BAY


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

     MEAN HIGHER HIGH WATER                     MHHW   =  0.400
     MEAN HIGH WATER                            MHW    =  0.389
     MEAN TIDE LEVEL                            MTL    =  0.203
     MEAN SEA LEVEL                             MSL    =  0.193
     MEAN LOW WATER                             MLW    =  0.017
     MEAN LOWER LOW WATER                       MLLW   =  0.000

North American Vertical Datum (NAVD88)

Bench Mark Elevation Information                In METERS above:

     Stamping or Designation                    MLLW        MHW

     NO 3 1976                                   1.131    0.742
     R114 BAY CO 1972                            3.415    3.026
     R115 BAY CO 1972                            4.579    4.190


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

                                                                                
Station ID: 8729119                         PUBLICATION DATE:  11/13/2003
Name:       SHELL ISLAND, ST. ANDREW B.                       
            FL
NOAA Chart: 11391                           Latitude:   30°  5.7' N (  30.09500)
USGS Quad:  BEACON BEACH                    Longitude:  85° 41.1' W ( -85.68500)


                             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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Products available at 8729119 SHELL ISLAND, ST. ANDREWS BAY, FL

Revised: 08/08/2018
NOAA / National Ocean Service
Web site owner: Center for Operational Oceanographic Products and Services