U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
Datums Page                                                        Page  1 of  4

                                                   PUBLICATION DATE:  08/23/1984
Station ID: 8729154                                SUPERCEDED DATE:   04/21/2003
Name:       BURNT MILL CREEK, WEST BAY                        
            FLORIDA
NOAA Chart: 11390                                  Latitude:         30° 19.7' N
USGS Quad:  WEST BAY                               Longitude:        85° 45.8' W


To reach the tidal bench marks from the intersection of State Highway 79 and
State Highway S-388 in West Bay proceed 5.8 miles (9.3 km) along State Highway
S-388 to the intersection of State Highway S-388 and South Burnt Mill Road. 
Continue south on South Burnt Mill Road to the residence of C.L. Boyd.  The
bench marks are located on the vicintiy of the Boyd residence and extend along
State Highway S-388 to the road bridge over Burnt Mill Creek.  The tide gage and
staff were located on the dock behind the Boyd residence.


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


                 PRIMARY BENCH MARK STAMPING:  9154 A 1976

MONUMENTATION:           Survey Disk                               VM#:    10027
AGENCY:                                                            PID#:  BE2977
SETTING CLASSIFICATION:  Copper-Coated Steel Rod


The bench mark is 180.0 feet (54.9 m) east of Bench Mark 9154 C 1976, 45.2 feet
(13.8 m) south of the centerline of State Highway S-388, 17.3 feet (5.3 m) east
of the centerline of Burnt Mill Road and 1.3 feet (0.4 m) south of a power pole.
 The bench mark is crimped to the copper-coated steel rod driven to refusal,
encased in a PVC pipe and concrete kickblock, 0.5 feet (0.1 m) below ground
level.



                         BENCH MARK STAMPING:  9154 B 1976

MONUMENTATION:           Survey Disk                               VM#:    10028
AGENCY:                                                            PID#:  BE2978
SETTING CLASSIFICATION:  Copper-Coated Steel Rod


The bench mark is on the Property of C.L. Boyd, 726.0 feet (221.3 m) south of
Bench Mark 9154 A 1976, 126.5 feet (38.6 m) ESE of the SE corner of the Boyd
residence, 25.0 feet (7.6 m) west of the centerline of south Burnt Mill Road and
2.8 feet (0.8 m) north of a power pole.  The bench mark is crimped to the
copper-coated steel rod driven to refusal, encased in a PVC pipe and concrete
kickblock, 0.6 feet (0.2 m) below ground level.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  2 of  4

                                                   PUBLICATION DATE:  08/23/1984
Station ID: 8729154                                SUPERCEDED DATE:   04/21/2003
Name:       BURNT MILL CREEK, WEST BAY                        
            FLORIDA
NOAA Chart: 11390                                  Latitude:         30° 19.7' N
USGS Quad:  WEST BAY                               Longitude:        85° 45.8' W


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


                         BENCH MARK STAMPING:  9154 C 1976

MONUMENTATION:           Survey Disk                               VM#:    10029
AGENCY:                                                            PID#:  BE2979
SETTING CLASSIFICATION:  Concrete Culvert


The bench mark is set flush in top of a concrete culvert on State Highway S-388,
223.0 feet (68.0 m) east of Bench Mark J 291, 220 feet (67.1 m) east of the east
end of the State Highway S-388 bridge over Burnt Mill Creek and 26.8 feet (8.2
m) south of the centerline of the highway, set flush into the center of the
concrete culvert.



                         BENCH MARK STAMPING:  H 291 1967

MONUMENTATION:           Survey Disk                               VM#:    10030
AGENCY:                                                            PID#:  BE0619
SETTING CLASSIFICATION:  Concrete Footing


The bench mark is set flush on the top of the west end ofthe north concrete
footing for the north bannister of the U.S. Highway S-388 bridge over Burnt Mill
Creek 295.3 feet (90.0 west of Bench Mark J 291 13.0 feet (4.0 m) nroth of
centerline of the highway, 0.4foot (0.12 m) south of the north bannister, 0.5
foot (0.15 m) above road level.



                         BENCH MARK STAMPING:  J 291

MONUMENTATION:           Survey Disk                               VM#:    10031
AGENCY:                                                            PID#:  BE0620
SETTING CLASSIFICATION:  Concrete Footing


The bench mark is set flush in the top of the east end of the south concrete
footing for the south concrete bannister of the U.S. Highway S-388 bridge over
Burnt Mill Creek,12.0 feet (3.7 m) south of the centerline of highway 0.8 foot
(0.24 m) north of the south concrete bannister 0.5 foot (0.15 m) above road
level.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  3 of  4

                                                   PUBLICATION DATE:  08/23/1984
Station ID: 8729154                                SUPERCEDED DATE:   04/21/2003
Name:       BURNT MILL CREEK, WEST BAY                        
            FLORIDA
NOAA Chart: 11390                                  Latitude:         30° 19.7' N
USGS Quad:  WEST BAY                               Longitude:        85° 45.8' W


                            T I D A L   D A T U M S 


Tidal datums at BURNT MILL CREEK, WEST BAY based on:

     LENGTH OF SERIES:      3 MONTHS
     TIME PERIOD:           OCTOBER-DECEMBER 1976
     TIDAL EPOCH:           1960-1978
     CONTROL TIDE STATION:  8729840 PENSACOLA


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

     HIGHEST OBSERVED WATER LEVEL (12/25/1975)         =   2.58
     MEAN HIGHER HIGH WATER                     MHHW   =   1.43
     MEAN HIGH WATER                            MHW    =   1.33
     MEAN TIDE LEVEL                            MTL    =   0.73
   * NATIONAL GEODETIC VERTICAL DATUM           NGVD29 =   0.24
     MEAN LOW WATER                             MLW    =   0.12
     MEAN LOWER LOW WATER                       MLLW   =   0.00
     LOWEST  OBSERVED WATER LEVEL (11/17/1976)         =  -1.26

   * NGVD is based on elevations published in Quad 300853, June 1973 and NOS
     leveling of October 1976. 
North American Vertical Datum (NAVD88)

Bench Mark Elevation Information                In FEET above:

     Stamping or Designation                    MLLW        MHW

     9154 A 1976                                16.65     15.22
     9154 B 1976                                12.38     10.98
     9154 C 1976                                14.99     13.56
     H 291 1967                                 12.73     11.30
     J 291                                      14.72     13.29


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

                                                   PUBLICATION DATE:  08/23/1984
Station ID: 8729154                                SUPERCEDED DATE:   04/21/2003
Name:       BURNT MILL CREEK, WEST BAY                        
            FLORIDA
NOAA Chart: 11390                                  Latitude:         30° 19.7' N
USGS Quad:  WEST BAY                               Longitude:        85° 45.8' 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.