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

                                                                                
Station ID: 8720006                         PUBLICATION DATE:  09/27/2013
Name:       LITTLE ST. MARYS RIVER                            
            FL
NOAA Chart: 11502                           Latitude:   30° 43.9' N (  30.73170)
USGS Quad:  GROSS                           Longitude:  81° 43.6' W ( -81.72670)


To reach the bench marks from the intersection of U.S. Highway 17 and State Road
A1A in Yulee, proceed NW on U.S. Highway 17 for 14.3 km (8.9 mi) to Owens Road;
then turn left and proceed SW on Owens Road for 1.3 km (0.8 mi) to the junction
of White Oak Plantation (a dirt road); then turn left and proceed NW on White
Oak Road for 2.7 km (1.7 mi) to a guard house and a gate.  From the guard house
go 0.8 m (0.5 mi) north to a wooden bridge over Little St. Mary's River.  The
bench marks are along the road between the gate and the bridge.  The tide gage
and staff were on the wooden bridge.  


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


                 PRIMARY BENCH MARK STAMPING:  0006 C 1977
                         DESIGNATION:          872 0006 C TIDAL

MONUMENTATION:           Tidal Station disk                    VM#:         4974
AGENCY:                  National Ocean Survey (NOS)           IDB PID#:  BC2443
SETTING CLASSIFICATION:  Copper-clad steel rod                 OPUS PID:        
LATITUDE:   30° 43.9' N (  30.73170)          LONGITUDE:  81° 43.4' W ( -81.72333)


The primary bench mark is a disk located 10.2 m (335.0 ft) SSE of rod mark 872
0006 G TIDAL, 6.7 m (22.0 ft) SW of the approximate centerline of White Oak
Road, 0.3 m (1.0 ft) west of a carsonite witness post and 0.3 m (1.0 ft) north
of a metal witness post.  The bench mark is set flush with the ground surface,
crimped to a steel rod, driven into the ground, encased in a 4-inch PVC pipe,
and concrete kickblock and set 0.9 m (0.3 ft) below the level of the ground.   
NOTE:  A magnet was buried at the south side of the mark.  

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

                                                                                
Station ID: 8720006                         PUBLICATION DATE:  09/27/2013
Name:       LITTLE ST. MARYS RIVER                            
            FL
NOAA Chart: 11502                           Latitude:   30° 43.9' N (  30.73170)
USGS Quad:  GROSS                           Longitude:  81° 43.6' W ( -81.72670)


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


                         BENCH MARK STAMPING:  0006 A 1977
                         DESIGNATION:          872 0006 A TIDAL

MONUMENTATION:           Tidal Station disk                    VM#:         4972
AGENCY:                  National Ocean Survey (NOS)           IDB PID#:  BC2445
SETTING CLASSIFICATION:  Copper-clad steel rod                 OPUS PID:        
LATITUDE:   30° 44.0' N (  30.73330)          LONGITUDE:  81° 43.5' W ( -81.72500)


The bench mark is a disk located SE of the bridge, 61 m (201 ft) SSW of a power
pole near the SE end of the bridge, 61 m (200 ft) SE of the SE end of the wooden
bridge, 6 m (19 ft) SW of the centerline of the road, and 0.15 m (0.5 ft) NE of
a witness post.  The bench mark is crimped to the top of a copper-clad steel rod
driven 14.6 m (48 ft) to refusal, and encased in a 4-inch PVC pipe.



                         BENCH MARK STAMPING:  0006 E 1977
                         DESIGNATION:          872 0006 E TIDAL

MONUMENTATION:           Tidal Station disk                    VM#:         4976
AGENCY:                  National Ocean Survey (NOS)           IDB PID#:  BC2441
SETTING CLASSIFICATION:  Copper-clad steel rod                 OPUS PID:        
LATITUDE:   30° 43.8' N (  30.73000)          LONGITUDE:  81° 43.2' W ( -81.72000)


The bench mark is a disk located SW of the gate and the guard house, on the
left.  The mark is 34.8 m (114 ft) WNW of the approximate center of a sand road
leading SW, 21 m (69.5 ft) WSW of the SE corner of the building, 14.3 m (46.8
ft) SW of the SW corner of the wood guard house building, and 10.7 m (35 ft) SSW
of the center of the median island where the building is located. The mark is
0.15 m (0.5 ft) NNE of a metal witness post, 0.3 m (1.0 ft) SSW of a carsonite
witness post.  The bench mark is set flush with the ground surface, crimped to a
steel rod driven into the ground 7 inches below ground level, and encased in a
4-inch PVC pipe.    Note:  The mark is stamped 000E 1977 and a magnet was buried
at the south side of the mark.  

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

                                                                                
Station ID: 8720006                         PUBLICATION DATE:  09/27/2013
Name:       LITTLE ST. MARYS RIVER                            
            FL
NOAA Chart: 11502                           Latitude:   30° 43.9' N (  30.73170)
USGS Quad:  GROSS                           Longitude:  81° 43.6' W ( -81.72670)


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


                         BENCH MARK STAMPING:  0006 F 2004

MONUMENTATION:           Flange-encased Rod                    VM#:        19176
AGENCY:                  National Geodetic Survey (NGS)        IDB PID#:        
SETTING CLASSIFICATION:  Stainless steel rod                   OPUS PID:        
LATITUDE:   30° 44.0' N (  30.73333)          LONGITUDE:  81° 43.5' W ( -81.72500)


The bench mark is a flange encased rod located 14.1 m (46.2 ft) ESE of the south
end of the SW steel guardrail at the south side of the bridge over the little
St. Marys River, 9.7 m (31.7 ft) NE of the approximate centerline of White Oak
Road, 7.9 m (26.0 ft) east of the SE steel guardrail of the bridge, 3.4 m (11.0
ft) east of a Bell South fiber optic marker post and 0.2 m (0.5 ft) NE of a
carsonite witness post.  The bench mark is a stainless steel rod driven to
refusal at a depth of 10.9 m (35.8 ft) with an NGS logo cap flush with the
ground and the datum point is recessed 0.12 m (0.4 ft) below the level of the
NGS logo cap.  Access to the datum point is had through the 5-inch NGS logo cap.
   NOTE:  A magnet was buried at the south side of the mark.  



                         BENCH MARK STAMPING:  0006 G 2004

MONUMENTATION:           Flange-encased Rod                    VM#:        19177
AGENCY:                  National Geodetic Survey (NGS)        IDB PID#:        
SETTING CLASSIFICATION:  Stainless steel rod                   OPUS PID:        
LATITUDE:   30° 44.0' N (  30.73333)          LONGITUDE:  81° 43.4' W ( -81.72333)


The bench mark is a flange-encased rod located 102.1 m (335.0 ft) NNW of Bench
Mark 0006 C  1977, 4.9 m (16.0 ft) ENE of the approximate centerline of White
Oak Road, 2 m (6.5 ft) SW of an 8-inch sweet gum tree, 0.6 m (2.0 ft) SW of the
SW side of a ditch, 0.6 m (2.0 ft) N and 0.5 m (1.7 ft) SE of carsonite witness
post.  The bench mark is a disk crimped to a stainless steel rod driven to
refusal at a depth of 7.8 m (25.6 ft), with an NGS logo cap, flush with the
ground and about level with White Oak Road, the datum point is recessed 0.12 m
(0.4 ft) below the level of the NGS logo cap.  Access to the datum point is had
through the 5-inch NGS logo cap.    NOTE:  A magnet was buried at the south side
of the mark.  

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

                                                                                
Station ID: 8720006                         PUBLICATION DATE:  09/27/2013
Name:       LITTLE ST. MARYS RIVER                            
            FL
NOAA Chart: 11502                           Latitude:   30° 43.9' N (  30.73170)
USGS Quad:  GROSS                           Longitude:  81° 43.6' W ( -81.72670)


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


                         BENCH MARK STAMPING:  0006 H 2004

MONUMENTATION:           Flange-encased Rod                    VM#:        19178
AGENCY:                  National Geodetic Survey (NGS)        IDB PID#:        
SETTING CLASSIFICATION:  Stainless steel rod                   OPUS PID:        
LATITUDE:   30° 43.8' N (  30.73000)          LONGITUDE:  81° 43.3' W ( -81.72167)


The bench mark is a disk located 10.8 m (35.5 ft) NE of the approximate
centerline of White Oak Road, 5 m (16.5 ft) NE of a Bell South cable junction
box number 11, 2.2 m (7.3 ft) SW of a 16-inch pine tree and 0.3 m (1.0 ft) NE of
a carsonite witness post.  The bench mark is a stainless steel rod driven to
refusal at a depth of 6.09 m (20.0 ft) with an NGS logo cap flush with the
ground and level with white oak road.  The datum point is recessed 0.12 m (0.4
ft below the level of the NGS logo cap.  Access to the datum point is had
through the 5-inch NGS logo cap    NOTE:  A magnet was buried at the south side
of the mark.  

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

                                                                                
Station ID: 8720006                         PUBLICATION DATE:  09/27/2013
Name:       LITTLE ST. MARYS RIVER                            
            FL
NOAA Chart: 11502                           Latitude:   30° 43.9' N (  30.73170)
USGS Quad:  GROSS                           Longitude:  81° 43.6' W ( -81.72670)


                            T I D A L   D A T U M S 


Tidal datums at LITTLE ST. MARYS RIVER based on:

     LENGTH OF SERIES:      1 MONTH
     TIME PERIOD:           February 1985 - February 1985
     TIDAL EPOCH:           1983-2001
     CONTROL TIDE STATION:  8720030 FERNANDINA BEACH, AMELIA RIVER


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

     MEAN HIGHER HIGH WATER                     MHHW   =  1.406
     MEAN HIGH WATER                            MHW    =  1.348
     MEAN SEA LEVEL                             MSL    =  0.793
     North American Vertical Datum              NAVD88 =  0.765
     MEAN TIDE LEVEL                            MTL    =  0.697
     MEAN LOW WATER                             MLW    =  0.046
     MEAN LOWER LOW WATER                       MLLW   =  0.000

North American Vertical Datum (NAVD88)

Bench Mark Elevation Information                In METERS above:

     Stamping or Designation                    MLLW        MHW

     0006 C 1977                                 1.724    0.376
     0006 A 1977                                 1.144   -0.204
     0006 E 1977                                 3.614    2.266
     0006 F 2004                                 1.525    0.177
     0006 G 2004                                 1.719    0.371
     0006 H 2004                                 1.560    0.212


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

                                                                                
Station ID: 8720006                         PUBLICATION DATE:  09/27/2013
Name:       LITTLE ST. MARYS RIVER                            
            FL
NOAA Chart: 11502                           Latitude:   30° 43.9' N (  30.73170)
USGS Quad:  GROSS                           Longitude:  81° 43.6' W ( -81.72670)


                             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.