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

                                                                                
Station ID: 8720007                         PUBLICATION DATE:  06/12/2009
Name:       ROSES BLUFF                                       
            FL
NOAA Chart: 11502                           Latitude:   30° 42.2' N (  30.70330)
USGS Quad:  ST. MARYS                       Longitude:  81° 34.6' W ( -81.57670)


To reach the tidal bench mark from the junction of State Road A1A (State Road
200), County Road 107 and Scott Road in O'Neil, go NW on A1A 3.4 km (2.1 mi) to
the junction of Chester Road, turn right and go north on Chester Road 5.4 km
(3.35 mi) to Roses Bluff Road, turn left and go WNW on Roses Bluff Road 2.8 km
(1.75 mi) to the end of the pavement, continue NW on the sand road 2.173 km
(1.35 mi) to the end of the road at the River Bluffs property, then turn left
into a private drive and follow the sand drive NW for 0.6 km (0.35 mi) to the
residences of Stuart Davis and John Davis.  The bench marks are located along a
trail road and grass drive, along the top and bottom of the bluff, east of the
Davis residences.  The tide gauge and staff were located on a private dock
behind the residence of Stuart Davis.


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


                 PRIMARY BENCH MARK STAMPING:  0007 A 1977
                         DESIGNATION:          872 0007 A TIDAL

MONUMENTATION:           Tidal Station disk                    VM#:         4977
AGENCY:                  National Ocean Survey (NOS)           IDB PID#:  BC2434
SETTING CLASSIFICATION:  Concrete monument                     OPUS PID:        
LATITUDE:   30° 42.2' N (  30.70330)          LONGITUDE:  81° 34.6' W ( -81.57667)


The primary bench mark is a disk set flush in a concrete monument flush with the
ground located west end of a grass drive, 67.7 m (222.0 ft) WNW of Bench Mark
0007 B 1977, 19 m (62.6 ft) SW of the SW corner of a 1.2 m (4.0 ft) wide wooden
walkway, to a boat dock, 15.5 m (51.0 ft) west of the center of the steps
leading to the top of the bluff, 4.0 m (13.0 ft) north of the base of the bluff,
and 3.5 m (11.5 ft) south of the river bank, and 0.2 m (0.5 ft) east of a metal
witness post.     NOTE: A magnet is 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: 8720007                         PUBLICATION DATE:  06/12/2009
Name:       ROSES BLUFF                                       
            FL
NOAA Chart: 11502                           Latitude:   30° 42.2' N (  30.70330)
USGS Quad:  ST. MARYS                       Longitude:  81° 34.6' W ( -81.57670)


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


                         BENCH MARK STAMPING:  0007 B 1977
                         DESIGNATION:          872 0007 B TIDAL

MONUMENTATION:           Tidal Station disk                    VM#:         4978
AGENCY:                  National Ocean Survey (NOS)           IDB PID#:  BC2433
SETTING CLASSIFICATION:  Copper-clad steel rod                 OPUS PID:        
LATITUDE:   30° 42.2' N (  30.70330)          LONGITUDE:  81° 33.7' W ( -81.56167)


The bench mark is a disk located 67.7 m (222 ft) ESE of Tidal Bench Mark 0007 A
1977, 54.9 m (180.0 ft) NW of Tidal Bench Mark 0007 C 1977, 7.3 m (24.0 ft)
south of the south bank of the Bells River, 3.05 m (10.0 ft) south of the
centerline of a grassy drive, and 0.3 m (1.0 ft) north of the base of the bluff.
 The bench mark is a disk crimped to a copper-clad steel rod driven into the
ground, encased in a 4-inch PVC pipe and concrete kickblock, 0.3 m (1.0 ft)
north of a carsonite witness post and projecting 0.06 m (0.2 ft) above the level
of the ground.     NOTE:  A magnet is 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: 8720007                         PUBLICATION DATE:  06/12/2009
Name:       ROSES BLUFF                                       
            FL
NOAA Chart: 11502                           Latitude:   30° 42.2' N (  30.70330)
USGS Quad:  ST. MARYS                       Longitude:  81° 34.6' W ( -81.57670)


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


                         BENCH MARK STAMPING:  0007 C 1977
                         DESIGNATION:          872 0007 C TIDAL

MONUMENTATION:           Tidal Station disk                    VM#:         4979
AGENCY:                  National Ocean Survey (NOS)           IDB PID#:  BC2432
SETTING CLASSIFICATION:  Copper-clad steel rod                 OPUS PID:        
LATITUDE:   30° 42.2' N (  30.70330)          LONGITUDE:  81° 33.7' W ( -81.56167)


The bench mark is a disk located 54.9 m (180.0 ft) SE of Bench Mark 0007 B 1977,
39 m (128.0 ft) ENE of Bench Mark 0007 D 1977, 8.53 m (28.0 ft) SW of the south
edge of the marsh at the south side of the Bells River, 5.5 m (18.0 ft) ENE of
the center of the drive leading to the base of the bluff, 3.35 m (11.0 ft) west
of a 19-inch oak tree, 2.7 m (9.0 ft) east of an 18-inch oak tree, 1.95 m (6.4
ft) NW of an 18-inch oak tree and 0.15 m (0.5 ft) NW of a metal witness post. 
The bench mark is a disk crimped to a copper-clad steel rod driven into the
ground, encased in a 4-inch PVC pipe and concrete kickblock, projecting 0.06 m
(0.2 ft) above the level of the ground.    NOTE: A magnet is 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: 8720007                         PUBLICATION DATE:  06/12/2009
Name:       ROSES BLUFF                                       
            FL
NOAA Chart: 11502                           Latitude:   30° 42.2' N (  30.70330)
USGS Quad:  ST. MARYS                       Longitude:  81° 34.6' W ( -81.57670)


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


                         BENCH MARK STAMPING:  0007 D 1977
                         DESIGNATION:          872 0007 D TIDAL

MONUMENTATION:           Tidal Station disk                    VM#:         4980
AGENCY:                  National Ocean Survey (NOS)           IDB PID#:  BC2431
SETTING CLASSIFICATION:  Copper-clad steel rod                 OPUS PID:        
LATITUDE:   30° 42.2' N (  30.70330)          LONGITUDE:  81° 34.6' W ( -81.57667)


The bench mark is a disk located 61.6 m (202.0 ft) east of Tidal Bench Mark 0007
E 1977, 39 m (128.0 ft) WSW of Tidal Bench Mark 0007 C 1977, 4.72 m (15.5 ft)
SSW of the centerline of the drive leading to the base of the bluff, 3.26 m
(10.7 ft) WNW of a 13-inch oak tree, and 0.15 m (0.5 ft) north of a metal
witness post.  The bench mark is a disk crimped to a copper-clad steel rod
driven into the ground, encased in a 4-inch PVC pipe and concrete kickblock
projecting 0.03 m (0.1 ft) above the level of the ground.    NOTE: A magnet is
buried at the south side of the mark.  



                         BENCH MARK STAMPING:  0007 E 1977
                         DESIGNATION:          872 0007 E TIDAL

MONUMENTATION:           Tidal Station disk                    VM#:         4981
AGENCY:                  National Ocean Survey (NOS)           IDB PID#:  BC2430
SETTING CLASSIFICATION:  Copper-clad steel rod                 OPUS PID:        
LATITUDE:   30° 42.2' N (  30.70330)          LONGITUDE:  81° 34.6' W ( -81.57667)


The bench mark is a disk located 61.6 m (202.0 ft) west of Tidal Bench Mark 0007
D 1977, 20.5 m (67.4 ft) ENE of the NW corner post for a deck at the one-story
elevated residence of John Davis, 14.6 m (48.0 ft) NE of the NE corner deck
post, 1.37 m (4.5 ft) ENE of a twin-trunk oak tree, 1.09 m (3.6 ft) north of an
oak tree, and 0.21 m (0.7 ft) north of a witness post.  The bench mark is a disk
crimped to a copper-clad steel rod driven into the ground, encased in a 4-inch
PVC pipe and concrete kickblock, projecting 0.03 m (0.1 ft) above the level of
the ground.    NOTE: A magnet is 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: 8720007                         PUBLICATION DATE:  06/12/2009
Name:       ROSES BLUFF                                       
            FL
NOAA Chart: 11502                           Latitude:   30° 42.2' N (  30.70330)
USGS Quad:  ST. MARYS                       Longitude:  81° 34.6' W ( -81.57670)


                            T I D A L   D A T U M S 


Tidal datums at ROSES BLUFF 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   =  2.047
     MEAN HIGH WATER                            MHW    =  1.942
     North American Vertical Datum              NAVD88 =  1.185
     MEAN SEA LEVEL                             MSL    =  1.055
     MEAN TIDE LEVEL                            MTL    =  0.999
     MEAN LOW WATER                             MLW    =  0.056
     MEAN LOWER LOW WATER                       MLLW   =  0.000

North American Vertical Datum (NAVD88)

Bench Mark Elevation Information                In METERS above:

     Stamping or Designation                    MLLW        MHW

     0007 A 1977                                 2.779    0.837
     0007 B 1977                                 2.892    0.950
     0007 C 1977                                 3.003    1.061
     0007 D 1977                                 6.494    4.552
     0007 E 1977                                 9.053    7.111


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

                                                                                
Station ID: 8720007                         PUBLICATION DATE:  06/12/2009
Name:       ROSES BLUFF                                       
            FL
NOAA Chart: 11502                           Latitude:   30° 42.2' N (  30.70330)
USGS Quad:  ST. MARYS                       Longitude:  81° 34.6' W ( -81.57670)


                             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.