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Bench Mark Sheet for 8728486, NE END, ST. GEORGE ISLAND

Superseded Epoch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Small blue map location marker Unpublished bench mark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: 8728486                         PUBLICATION DATE:  11/13/2003
Name:       NE END, ST. GEORGE ISLAND                         
            FL
NOAA Chart: 11401                           Latitude:   29° 46.0' N (  29.76670)
USGS Quad:  CARRABELLE                      Longitude:  84° 42.0' W ( -84.70000)


To reach the tidal bench marks from the entrance to St. George Island State
Park, proceed east on County Route 300 for 11.83 km (7.35 mi) to the end of the
pavement, then continue with a four-wheel drive vehicle east on a sand road to
the beach, then proceed NE along the beach to the NE end of the island.  The
bench marks are located along the dune line at the NE end of the island.  The
tide gage and staff were located on a three-pile platform, 91 m (300 ft) NW of
the NE end of the island on the St. George Sound side.


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


                 PRIMARY BENCH MARK STAMPING:  8486 A 1983
                         DESIGNATION:          872 8486 A TIDAL

MONUMENTATION:           Tidal Station disk                    VM#:         9834
AGENCY:                  National Ocean Survey (NOS)           IDB PID#:        
SETTING CLASSIFICATION:  Stainless steel rod                   OPUS PID:        
LATITUDE:   29° 46.0' N (  29.76670)          LONGITUDE:  84° 42.0' W ( -84.70000)


The primary bench mark is a disk located at the NE end of St. George Island on
the St. George Sound side, 5 m (17 ft) ESE of the SE post of a sign reading No
Vehicles Beyond This Point, 0.76 m (2.5 ft) WNW of a 0.18 m (0.6 ft) diameter
piling, and 0.61 m (2.0 ft)  ESE of a witness post on a piling.  The bench mark
is set at ground level, crimped to the top of a stainless steel rod driven 17.1
m (56 ft) to substantial resistance, and encased in a 4-inch PVC pipe and
concrete kickblock.

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

                                                                                
Station ID: 8728486                         PUBLICATION DATE:  11/13/2003
Name:       NE END, ST. GEORGE ISLAND                         
            FL
NOAA Chart: 11401                           Latitude:   29° 46.0' N (  29.76670)
USGS Quad:  CARRABELLE                      Longitude:  84° 42.0' W ( -84.70000)


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


                         BENCH MARK STAMPING:  B 341 1977
                         DESIGNATION:          B 341

MONUMENTATION:           Bench Mark disk                       VM#:         9833
AGENCY:                  US Coast and Geodetic Survey
                         (USC&GS)                              IDB PID#:  AS0451
SETTING CLASSIFICATION:  Copper-clad steel rod                 OPUS PID:        
LATITUDE:   29° 45.4' N (  29.75670)          LONGITUDE:  84° 42.1' W ( -84.70170)


The bench mark is a disk located 430 m (1410 ft) south of bench mark 49 80 B34,
91 m (300 ft) west of the approximate high water line, and 1 m (2 ft) south of a
witness post at the edge of the vegetation line.  The bench mark is crimped to
the top of a copper-clad steel rod driven 17.1 m (56 ft), and encased in a pipe
projecting 0.09 m (0.3 ft) above the ground.  NOTE: The area has changed
considerably since Hurricane Kate (1984, FLDNR).  Mark not found in 1984 by
Florida Department of Natural Resources.



                         BENCH MARK STAMPING:   8486 B 1983
                         DESIGNATION:          872 8486 B TIDAL

MONUMENTATION:           Tidal Station disk                    VM#:         9835
AGENCY:                  National Ocean Survey (NOS)           IDB PID#:        
SETTING CLASSIFICATION:  Stainless steel rod                   OPUS PID:        
LATITUDE:   29° 46.0' N (  29.76670)          LONGITUDE:  84° 42.0' W ( -84.70000)


The bench mark is a disk located 107 m (350 ft) south of bench mark 8486 A 1983,
36 m (119 ft) ESE of the shoreward edge of the dune line on St. George Island,
and 0.55 m (1.8 ft) NW of a witness post.  The bench mark is set at ground
level, crimped to the top of a stainless steel rod driven 19.5 m (64 ft) to
substantial resistance, and encased in a 4-inch PVC pipe and concrete kickblock.

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

                                                                                
Station ID: 8728486                         PUBLICATION DATE:  11/13/2003
Name:       NE END, ST. GEORGE ISLAND                         
            FL
NOAA Chart: 11401                           Latitude:   29° 46.0' N (  29.76670)
USGS Quad:  CARRABELLE                      Longitude:  84° 42.0' W ( -84.70000)


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


                         BENCH MARK STAMPING:  8486 C 1983
                         DESIGNATION:          872 8486 C TIDAL

MONUMENTATION:           Tidal Station disk                    VM#:         9836
AGENCY:                  National Ocean Survey (NOS)           IDB PID#:        
SETTING CLASSIFICATION:  Stainless steel rod                   OPUS PID:        
LATITUDE:   29° 46.0' N (  29.76670)          LONGITUDE:  84° 42.0' W ( -84.70000)


The bench mark is a disk located 61 m (200 ft) SSW of bench mark 8486 B 1983, 40
m (130 ft) ESE of the shoreward edge of the vegetation line on St. George
Island, and 0.52 m (1.7 ft) NNE of the witness post atop a prominent dune.  The
bench mark is set at ground level, crimped to the top of a stainless steel rod
driven 19.5 m (64 ft) to substantial resistance, and encased in a 4-inch PVC
pipe and concrete kickblock.



                         BENCH MARK STAMPING:  49 80 B34
                         DESIGNATION:          49 80 B34

MONUMENTATION:           Bench Mark disk                       VM#:         9837
AGENCY:                  Florida Department of Natural Resources
                         (FLDNR)                               IDB PID#:  AS0577
SETTING CLASSIFICATION:  Concrete monument                     OPUS PID:        
LATITUDE:   29° 46.2' N (  29.77000)          LONGITUDE:  84° 41.8' W ( -84.69670)


The bench mark is a disk set in the top of a round concrete monument, 91 m (300
ft) west of the east vegetation line, 55 m (180 ft) SE of bench mark 8486C 1983,
and 1.13 m (3.7 ft) east of a witness post.

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

                                                                                
Station ID: 8728486                         PUBLICATION DATE:  11/13/2003
Name:       NE END, ST. GEORGE ISLAND                         
            FL
NOAA Chart: 11401                           Latitude:   29° 46.0' N (  29.76670)
USGS Quad:  CARRABELLE                      Longitude:  84° 42.0' W ( -84.70000)


                            T I D A L   D A T U M S 


Tidal datums at NE END, ST. GEORGE ISLAND based on:

     LENGTH OF SERIES:      1 MONTH
     TIME PERIOD:           September 1983 - September 1983
     TIDAL EPOCH:           1983-2001
     CONTROL TIDE STATION:  8728690 APALACHICOLA, APALACHICOLA RIVER


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

     MEAN HIGHER HIGH WATER                     MHHW   =  0.670
     MEAN HIGH WATER                            MHW    =  0.627
     MEAN TIDE LEVEL                            MTL    =  0.389
     North American Vertical Datum              NAVD88 =  0.383
     MEAN SEA LEVEL                             MSL    =  0.366
     MEAN LOW WATER                             MLW    =  0.151
     MEAN LOWER LOW WATER                       MLLW   =  0.000

North American Vertical Datum (NAVD88)

Bench Mark Elevation Information                In METERS above:

     Stamping or Designation                    MLLW        MHW

     8486 A 1983                                 1.284    0.657
     B 341 1977                                  1.260    0.633
      8486 B 1983                                1.052    0.425
     8486 C 1983                                 2.612    1.985
     49 80 B34                                   2.717    2.090


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

                                                                                
Station ID: 8728486                         PUBLICATION DATE:  11/13/2003
Name:       NE END, ST. GEORGE ISLAND                         
            FL
NOAA Chart: 11401                           Latitude:   29° 46.0' N (  29.76670)
USGS Quad:  CARRABELLE                      Longitude:  84° 42.0' W ( -84.70000)


                             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 8728486 NE END, ST. GEORGE ISLAND,

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