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

                                                   PUBLICATION DATE:  06/12/1985
Station ID: 8728464                                SUPERCEDED DATE:   04/21/2003
Name:       CARRABELLE, CARRABELLE RIVER                      
            FLORIDA
NOAA Chart: 11405                                  Latitude:         29° 51.0' N
USGS Quad:  CARRABELLE                             Longitude:        84° 39.9' W


To reach the tidal bench marks from the Post Office at Carrabelle, proceed south
along Highway S67 (Marine Street) 0.1 mile (0.2 km) to Rileys Bait and Tackle
shop.  The bench marks are along Highway S67 from Avenue B South to Avenue C
North, and the gage and staff were located on the dock behind Rileys Bait and
Tackle shop.


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


                 PRIMARY BENCH MARK STAMPING:  8464 A 1977

MONUMENTATION:           Survey Disk                               VM#:     9828
AGENCY:                                                            PID#:  AI3229
SETTING CLASSIFICATION:  Concrete Pad


The bench mark is set flush into the concrete apron between the doors of the
Carrabelle Fire Department, 49 feet (15 m) west of the centerline of Highway
S67, 48 feet (14.6 m) NW of utility pole NO 5-11349 and 31.4 feet (9.6 m) south
of the NE corner of the station.



                         BENCH MARK STAMPING:  8464 B 1977

MONUMENTATION:           Survey Disk                               VM#:     9829
AGENCY:                                                            PID#:  AI3230
SETTING CLASSIFICATION:  Concrete Post


The bench mark is 0.1 mile, (0.2 km) north along Highway S67 from the Post
Office at Carrabelle, 32.7 feet (10.0 m) east of the centerline of the Highway,
12.0 feet (3.7 m) SSW of the SW corner of a house porch and 3.0 feet (0.9 m)
east of a brick and block wall surrounding the residence yard, and is crimped to
a 5/8 inch diameter rebar set into a poured concrete post.

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

                                                   PUBLICATION DATE:  06/12/1985
Station ID: 8728464                                SUPERCEDED DATE:   04/21/2003
Name:       CARRABELLE, CARRABELLE RIVER                      
            FLORIDA
NOAA Chart: 11405                                  Latitude:         29° 51.0' N
USGS Quad:  CARRABELLE                             Longitude:        84° 39.9' W


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


                         BENCH MARK STAMPING:  8464 C 1977

MONUMENTATION:           Survey Disk                               VM#:     9830
AGENCY:                                                            PID#:  AI3231
SETTING CLASSIFICATION:  Copper-clad Steel Rod


The bench mark is 0.2 miles (0.3 km) north along Highway S67 from the Post
Office at Carrabelle, 35 feet (10.7 m) south of the centerline of Avenue C
North, 30.2 feet (9.2 m) east of the NE corner of Rileys Funeral Home, 25 feet
(8 m) west of the centerline of Highway S67 and 4.5 feet (1.4 m) south of
utility pole NO 58X-805.  The bench mark is crimped to a 5/8 inch diameter 
copper-clad steel rod driven 40 feet (12 m) encased in a protector pipe and
concrete kickblock, 0.5 foot (0.2 m) below ground level.



                         BENCH MARK STAMPING:  P 293 1967

MONUMENTATION:           Survey Disk                               VM#:     9831
AGENCY:                                                            PID#:  AS0228
SETTING CLASSIFICATION:  Brick Foundation


The bench mark is at Carabelle, set vertically in the south brick face and near
the SW corner of the Post Office building 104 feet (32 m) west of the centerline
of Highway S67, 65 feet (20 m) north of U.S. Highways 319 and 98 and 1.6 feet
(0.5 m) east of the SW corner and level with the highway.

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

                                                   PUBLICATION DATE:  06/12/1985
Station ID: 8728464                                SUPERCEDED DATE:   04/21/2003
Name:       CARRABELLE, CARRABELLE RIVER                      
            FLORIDA
NOAA Chart: 11405                                  Latitude:         29° 51.0' N
USGS Quad:  CARRABELLE                             Longitude:        84° 39.9' W


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


                         BENCH MARK STAMPING:  NO 2 01934

MONUMENTATION:           Survey Disk                               VM#:     9832
AGENCY:                                                            PID#:  AS0230
SETTING CLASSIFICATION:  Concrete Sidewalk


The bench mark is about 200 feet (61 m) south of the intersection of U.S.
Highway 319 and 98 and State Highway S67, set into the sidewalk at the SE corner
of a one story brick building used by the High Hat Tavern, 6.2 feet (1.9 m) west
of the west curb of State Highway S67 and 0.7 foot (0.2 m) NE of the SE corner
of the building and level with the highway.

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

                                                   PUBLICATION DATE:  06/12/1985
Station ID: 8728464                                SUPERCEDED DATE:   04/21/2003
Name:       CARRABELLE, CARRABELLE RIVER                      
            FLORIDA
NOAA Chart: 11405                                  Latitude:         29° 51.0' N
USGS Quad:  CARRABELLE                             Longitude:        84° 39.9' W


                            T I D A L   D A T U M S 


Tidal datums at CARRABELLE, CARRABELLE RIVER based on:

     LENGTH OF SERIES:      4 MONTHS
     TIME PERIOD:           November 1977 - February 1978
     TIDAL EPOCH:           1960-1978
     CONTROL TIDE STATION:  8728360 TURKEY POINT


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

     HIGHEST OBSERVED WATER LEVEL (01/25/1978)         =   3.33
     MEAN HIGHER HIGH WATER                     MHHW   =   2.38
     MEAN HIGH WATER                            MHW    =   2.16
     MEAN TIDE LEVEL                            MTL    =   1.37
   * NATIONAL GEODETIC VERTICAL DATUM           NGVD29 =   0.82
     MEAN LOW WATER                             MLW    =   0.59
     MEAN LOWER LOW WATER                       MLLW   =   0.00
     LOWEST  OBSERVED WATER LEVEL (11/11/1977)         =  -1.86

   * NGVD reference based on elevations published in Quad 290844, 1983, and NOS
     leveling of 1978. 
North American Vertical Datum (NAVD88)

Bench Mark Elevation Information                In FEET above:

     Stamping or Designation                    MLLW        MHW

     8464 A 1977                                14.30     12.14
     8464 B 1977                                18.19     16.03
     8464 C 1977                                21.44     19.28
     P 293 1967                                 12.51     10.35
     NO 2 01934                                 13.37     11.21


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

                                                   PUBLICATION DATE:  06/12/1985
Station ID: 8728464                                SUPERCEDED DATE:   04/21/2003
Name:       CARRABELLE, CARRABELLE RIVER                      
            FLORIDA
NOAA Chart: 11405                                  Latitude:         29° 51.0' N
USGS Quad:  CARRABELLE                             Longitude:        84° 39.9' 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.