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

                                                   PUBLICATION DATE:  10/01/1987
Station ID: 8720007                                SUPERCEDED DATE:   04/21/2003
Name:       ROSE BLUFF, BELLS RIVER                           
            FLORIDA
NOAA Chart: 11502                                  Latitude:         30° 42.2' N
USGS Quad:  ST. MARYS                              Longitude:        81° 34.6' W


To reach the tidal bench marks from the intersection of U.S. Highway 17 and
State Highway A1A in Yulee, proceed NW on U.S. Highway 17 for 3.7 miles (6.0 km)
to Crandall Road, then NE on Crandall Road for 2.8 miles (4.5 km) to Rayonier
Timber Road #8, go 0.1 mile (0.2 km) SE on Road #8 to the fork in the road, bear
left (east) onto Road #6 for 3.3 miles (5.3 km) to the residence of Stuart
Davis.  The bench marks are located in the area around the property.  The tide
gage 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

MONUMENTATION:           Survey Disk                               VM#:     4977
AGENCY:                                                            PID#:  BC2434
SETTING CLASSIFICATION:  Concrete Monument


The bench mark is set flush in a concrete monument at the base of a high bluff,
222 feet (68 m) west of Bench Mark 0007 B 1977, 63 feet (19 m) SW of the south
end of the easternmost dock, and 13 feet (4 m) north of the base of the bluff.



                         BENCH MARK STAMPING:  0007 B 1977

MONUMENTATION:           Survey Disk                               VM#:     4978
AGENCY:                                                            PID#:  BC2433
SETTING CLASSIFICATION:  Stainless Steel Rod


The bench mark is at the base of a high bluff, 222 feet (68 m) east of the west
end of the grassy drive, 180 feet (55 m) west of Bench Mark 0007 C 1977, and 10
feet (3 m) south of the centerline of a grassy drive.  The bench mark is crimped
to a stainless steel rod driven 48 feet (15 m) to refusal, 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

                                                   PUBLICATION DATE:  10/01/1987
Station ID: 8720007                                SUPERCEDED DATE:   04/21/2003
Name:       ROSE BLUFF, BELLS RIVER                           
            FLORIDA
NOAA Chart: 11502                                  Latitude:         30° 42.2' N
USGS Quad:  ST. MARYS                              Longitude:        81° 34.6' W


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


                         BENCH MARK STAMPING:  0007 C 1977

MONUMENTATION:           Survey Disk                               VM#:     4979
AGENCY:                                                            PID#:  BC2432
SETTING CLASSIFICATION:  Stainless Steel Rod


The bench mark is 128 feet (39 m) ENE of Bench Mark 0007 D 1977, 18 feet (5 m)
east of the centerline of the drive leading to the base of the bluff, 10 feet (3
m) NE of a large oak tree, 6.4 feet (2.0 m) NW of another large oak tree and 0.5
foot (0.2 m) NW of a Witness post.  The bench mark is crimped to a stainless
steel rod driven 48 feet (15 m) to refusal, and encased in a 4-inch PVC pipe and
concrete kickblock.



                         BENCH MARK STAMPING:  0007 D 1977

MONUMENTATION:           Survey Disk                               VM#:     4980
AGENCY:                                                            PID#:  BC2431
SETTING CLASSIFICATION:  Stainless Steel Rod


The bench mark is 202 feet (62 m) east of Bench Mark 0007 E 1977, 15 feet (5 m)
SSW of the centerline of the drive leading to the base of the bluff, 14.4 feet
(4.4 m) ENE of a cedar tree, and 0.5 foot (0.2 m) north of a witness post.  The
bench mark is crimped to a stainless steel rod driven 48 feet (15 m) to refusal,
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

                                                   PUBLICATION DATE:  10/01/1987
Station ID: 8720007                                SUPERCEDED DATE:   04/21/2003
Name:       ROSE BLUFF, BELLS RIVER                           
            FLORIDA
NOAA Chart: 11502                                  Latitude:         30° 42.2' N
USGS Quad:  ST. MARYS                              Longitude:        81° 34.6' W


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


                         BENCH MARK STAMPING:  0007 E 1977

MONUMENTATION:           Survey Disk                               VM#:     4981
AGENCY:                                                            PID#:  BC2430
SETTING CLASSIFICATION:  Stainless Steel Rod


The bench mark is 77 feet (23 m) south of the top edge of the bluff, 31 feet (9
m) ESE of the junction of an eroded drive leading north down the bluff and a
drive leading east to the base of the bluff, 12 feet (4 m) south of the
centerline of the road, 5 feet (2 m) ENE of a twin trunk oak tree, and 0.5 foot
(0.2 m) north of a witness post.  The bench mark is crimped to a stainless steel
rod driven 48 feet (15 m) to refusal, 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  4 of  5

                                                   PUBLICATION DATE:  10/01/1987
Station ID: 8720007                                SUPERCEDED DATE:   04/21/2003
Name:       ROSE BLUFF, BELLS RIVER                           
            FLORIDA
NOAA Chart: 11502                                  Latitude:         30° 42.2' N
USGS Quad:  ST. MARYS                              Longitude:        81° 34.6' W


                            T I D A L   D A T U M S 


Tidal datums at ROSE BLUFF, BELLS RIVER based on:

     LENGTH OF SERIES:      1 MONTH
     TIME PERIOD:           FEBRUARY 1985
     TIDAL EPOCH:           1960-1978
     CONTROL TIDE STATION:  8720030 FERNANDINA BEACH


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

     HIGHEST OBSERVED WATER LEVEL (02/19/1978)         =   8.37
     MEAN HIGHER HIGH WATER                     MHHW   =   6.76
     MEAN HIGH WATER                            MHW    =   6.43
     MEAN TIDE LEVEL                            MTL    =   3.31
     MEAN LOW WATER                             MLW    =   0.19
     MEAN LOWER LOW WATER                       MLLW   =   0.00
     LOWEST  OBSERVED WATER LEVEL (02/12/1985)         =  -1.55

North American Vertical Datum (NAVD88)

Bench Mark Elevation Information                In FEET above:

     Stamping or Designation                    MLLW        MHW

     0007 A 1977                                 9.39      2.96
     0007 B 1977                                 9.76      3.33
     0007 C 1977                                10.12      3.69
     0007 D 1977                                21.58     15.15
     0007 E 1977                                29.97     23.54


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

                                                   PUBLICATION DATE:  10/01/1987
Station ID: 8720007                                SUPERCEDED DATE:   04/21/2003
Name:       ROSE BLUFF, BELLS RIVER                           
            FLORIDA
NOAA Chart: 11502                                  Latitude:         30° 42.2' N
USGS Quad:  ST. MARYS                              Longitude:        81° 34.6' W


                             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 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.