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

                                                   PUBLICATION DATE:  04/26/2000
Station ID: 8729015                                SUPERCEDED DATE:   04/21/2003
Name:       ALLANTON, EAST BAY                                
            FLORIDA
NOAA Chart: 11389                                  Latitude:         30°  1.8' N
USGS Quad:  ALLANTON                               Longitude:        85° 27.9' W


To reach the tidal bench marks from the intersection of U.S. Highway 98 and
State Road 22 at Callaway, proceed east on State Road 22 for 9.2 km (5.7 mi) to
County Road 2297, turn right and go south on County Road 2297 for 15.0 km (9.3
mi) to the end of the paved road and Allanton Road on the left, turn left and go
east for 0.6 km (0.4 mi) to the end of pavement, continue on the dirt road for
1.2 km (0.8 mi) to the E.R. Allan driveway, turn right and go south for 0.3 km
0.2 mi).  The bench marks are on C.D. King's and E.R. Allan's properties.  The
tide gage and staff were at the end of a wooden dock on the Allan property.


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


                 PRIMARY BENCH MARK STAMPING:  NO 1 1975
                         DESIGNATION:          872 9015 TIDAL 1

MONUMENTATION:           Tidal Station disk                        VM#:     9942
AGENCY:                  National Ocean Survey (NOS)               PID#:  BE1733
SETTING CLASSIFICATION:  Copper-clad steel rod


The primary bench mark is a disk set 0.3 km (0.2 mile) south of C.D. King's
mailbox along the driveway to his residence, 32 m (105 ft) north of the
approximate shoreline, 23 m (75 ft) ESE of the SE corner of C.D. King's
residence, and 1.49 m (4.9 ft) east of a 0.67 m (2.2 ft) diameter pecan tree. 
The bench mark is crimped to a copper-clad steel rod driven to an unspecified
depth.



                         BENCH MARK STAMPING:  C D KING 1975
                         DESIGNATION:          872 9015 TIDAL C D KING

MONUMENTATION:           Tidal Station disk                        VM#:     9943
AGENCY:                  National Ocean Survey (NOS)               PID#:  BE1731
SETTING CLASSIFICATION:  Copper-clad steel rod


The bench mark is a disk set 0.24 km (0.15 mile) south of C.D. King's mailbox
along the driveway to his residence, 53.9 m (177 ft)  south of Bench Mark NO 4
1975, 4.54 m (14.9 ft) west of the centerline of C.D. King's driveway, 3 m (10
ft) east of a fence line, 2 m (7 ft) NE of a barn, and 0.49 m (1.6 ft) north of
a power pole.  The bench mark is level with the dirt driveway, crimped to a
copper-clad steel rod driven to an unspecified depth.

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

                                                   PUBLICATION DATE:  04/26/2000
Station ID: 8729015                                SUPERCEDED DATE:   04/21/2003
Name:       ALLANTON, EAST BAY                                
            FLORIDA
NOAA Chart: 11389                                  Latitude:         30°  1.8' N
USGS Quad:  ALLANTON                               Longitude:        85° 27.9' W


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


                         BENCH MARK STAMPING:  NO 3 1975
                         DESIGNATION:          872 9015 TIDAL 3

MONUMENTATION:           Tidal Station disk                        VM#:     9944
AGENCY:                  National Ocean Survey (NOS)               PID#:  BE1732
SETTING CLASSIFICATION:  Concrete monument


The bench mark is a disk set in the top of a concrete monument, 0.3 km (0.2
mile) south of C.D. King's mailbox along the driveway to his residence, 33 m
(108 ft) north of a sea wall, 16.31 m (53.5 ft) WNW of the NW corner of the C.D.
King residence, 16 m (52 ft) ESE of power pole #4, and 0.3 m (1 ft) below the
level of the driveway.



                         BENCH MARK STAMPING:  9015 A 1988
                         DESIGNATION:          872 9015 A

MONUMENTATION:           Tidal Station disk                        VM#:     9946
AGENCY:                  National Ocean Service (NOS)              PID:         
SETTING CLASSIFICATION:  Concrete monument


The bench mark is a disk set in a concrete monument on E.R. Allan's property
(residence just west of C.D. King's), 137 m (450 ft) south of a graded dirt
road, 91 m (300 ft) east of the E.R. Allan Residence, and 69 m (225 ft) north of
the approximate shoreline.

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

                                                   PUBLICATION DATE:  04/26/2000
Station ID: 8729015                                SUPERCEDED DATE:   04/21/2003
Name:       ALLANTON, EAST BAY                                
            FLORIDA
NOAA Chart: 11389                                  Latitude:         30°  1.8' N
USGS Quad:  ALLANTON                               Longitude:        85° 27.9' W


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


                         BENCH MARK STAMPING:  NO 4 1975
                         DESIGNATION:          872 9015 TIDAL 4

MONUMENTATION:           Tidal Station disk                        VM#:    12509
AGENCY:                  National Ocean Survey (NOS)               PID#:  BE1730
SETTING CLASSIFICATION:  Concrete monument


The bench mark is a disk set 0.16 km (0.10 mile) south of C.D. King's mailbox
along the driveway to his residence, 61 m (200 ft) south of Bench Mark NO 5
1975, 2.41 m (7.9 ft) east of a fence line, and 0.3 m (1 ft) west of a power
pole.

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

                                                   PUBLICATION DATE:  04/26/2000
Station ID: 8729015                                SUPERCEDED DATE:   04/21/2003
Name:       ALLANTON, EAST BAY                                
            FLORIDA
NOAA Chart: 11389                                  Latitude:         30°  1.8' N
USGS Quad:  ALLANTON                               Longitude:        85° 27.9' W


                            T I D A L   D A T U M S 


Tidal datums at ALLANTON, EAST BAY based on:

     LENGTH OF SERIES:      1 YEAR
     TIME PERIOD:           February 1976 - January 1977
     TIDAL EPOCH:           1960-1978
     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   =  0.471
     MEAN HIGH WATER                            MHW    =  0.434
     North American Vertical Datum              NAVD88 =  0.236
     MEAN TIDE LEVEL                            MTL    =  0.235
     MEAN SEA LEVEL                             MSL    =  0.231
     MEAN LOW WATER                             MLW    =  0.036
     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 1 1975                                   1.012    0.579
     C D KING 1975                               1.423    0.989
     NO 3 1975                                   1.162    0.728
     9015 A 1988                                 1.448    1.014
     NO 4 1975                                   0.926    0.492


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

                                                   PUBLICATION DATE:  04/26/2000
Station ID: 8729015                                SUPERCEDED DATE:   04/21/2003
Name:       ALLANTON, EAST BAY                                
            FLORIDA
NOAA Chart: 11389                                  Latitude:         30°  1.8' N
USGS Quad:  ALLANTON                               Longitude:        85° 27.9' 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.