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

                                                   PUBLICATION DATE:  03/28/1988
Station ID: 8725331                                SUPERCEDED DATE:   04/21/2003
Name:       ESTERO ISLAND, OSTEGO BAY                         
            FLORIDA
NOAA Chart: 11426                                  Latitude:         26° 24.8' N
USGS Quad:  FORT MYERS BEACH                       Longitude:        81° 53.9' W


To reach the tidal bench marks from the draw bridge over Big Carlos Pass,
proceed WNW on County Road 865 for about 1.5 miles (2.4 km) to the Fish Tale
Marina at 7105 Estero Boulevard.  The bench marks are located on the western and
the southern  sea walls of the marina.  The tide gage and staff were located at
the end of the walkway leading to a boat shed.


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


                 PRIMARY BENCH MARK STAMPING:  NO 1 1973

MONUMENTATION:           Survey Disk                               VM#:     8021
AGENCY:                                                            PID#:  AD7858
SETTING CLASSIFICATION:  Concrete Sea Wall


The bench mark is set flush in the concrete sea wall south of a boat lift, and
61.4 feet (18.7 m) north of the south edge of a floating dock.



                         BENCH MARK STAMPING:  NO 2 1973

MONUMENTATION:           Survey Disk                               VM#:     8022
AGENCY:                                                            PID:         
SETTING CLASSIFICATION:  Concrete Sea Wall


The bench mark is set flush in the concrete sea wall south of a boat lift, 69.8
feet (21.3 m) south of Bench Mark NO 1 1973, and 8.4 feet (2.6 m) south of the
south edge of a floating dock.

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

                                                   PUBLICATION DATE:  03/28/1988
Station ID: 8725331                                SUPERCEDED DATE:   04/21/2003
Name:       ESTERO ISLAND, OSTEGO BAY                         
            FLORIDA
NOAA Chart: 11426                                  Latitude:         26° 24.8' N
USGS Quad:  FORT MYERS BEACH                       Longitude:        81° 53.9' W


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


                         BENCH MARK STAMPING:  NO 3 1973

MONUMENTATION:           Survey Disk                               VM#:     8023
AGENCY:                                                            PID#:  AD7859
SETTING CLASSIFICATION:  Concrete Sea Wall


The bench mark is set flush in the concrete sea wall, 93.3 feet (28.4 m) south
of Bench Mark NO 2 1973, 24.5 feet (7.5 m) west of the NW corner of the boat
shed, and 4.1 feet (1.2 m) south of the south edge of the walkway leading to the
boat shed.



                         BENCH MARK STAMPING:  NO 4 1973

MONUMENTATION:           Survey Disk                               VM#:     8024
AGENCY:                                                            PID#:  AD7860
SETTING CLASSIFICATION:  Concrete Sea Wall


The bench mark is set flush in the concrete sea wall at the SW corner of the
marina, 122.2 feet (37.2 m) south of Bench Mark NO 3 1973, and 3.6 feet (1.1
m)north of the south end of the sea wall.



                         BENCH MARK STAMPING:  NO 5 1973

MONUMENTATION:           Survey Disk                               VM#:     8025
AGENCY:                                                            PID#:  AD7861
SETTING CLASSIFICATION:  Concrete Sea Wall


The bench mark is set flush in the concrete sea wall, 63.5 feet (19.4 m) east of
the SW corner of the sea wall, and 63.5 feet (19.4 m) east of Bench Mark NO 4
1973.

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

                                                   PUBLICATION DATE:  03/28/1988
Station ID: 8725331                                SUPERCEDED DATE:   04/21/2003
Name:       ESTERO ISLAND, OSTEGO BAY                         
            FLORIDA
NOAA Chart: 11426                                  Latitude:         26° 24.8' N
USGS Quad:  FORT MYERS BEACH                       Longitude:        81° 53.9' W


                            T I D A L   D A T U M S 


Tidal datums at ESTERO ISLAND, OSTEGO BAY based on:

     LENGTH OF SERIES:      1 MONTH
     TIME PERIOD:           JUNE 1973
     TIDAL EPOCH:           1960-1978
     CONTROL TIDE STATION:  8725110 NAPLES


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

     HIGHEST OBSERVED WATER LEVEL (05/28/1973)         =   3.30
     MEAN HIGHER HIGH WATER                     MHHW   =   2.54
     MEAN HIGH WATER                            MHW    =   2.28
     MEAN TIDE LEVEL                            MTL    =   1.37
     MEAN LOW WATER                             MLW    =   0.46
     MEAN LOWER LOW WATER                       MLLW   =   0.00
     LOWEST  OBSERVED WATER LEVEL (05/16/1973)         =  -0.78

North American Vertical Datum (NAVD88)

Bench Mark Elevation Information                In FEET above:

     Stamping or Designation                    MLLW        MHW

     NO 1 1973                                   4.88      2.60
     NO 2 1973                                   4.89      2.61
     NO 3 1973                                   4.82      2.54
     NO 4 1973                                   5.01      2.73
     NO 5 1973                                   4.20      1.92


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

                                                   PUBLICATION DATE:  03/28/1988
Station ID: 8725331                                SUPERCEDED DATE:   04/21/2003
Name:       ESTERO ISLAND, OSTEGO BAY                         
            FLORIDA
NOAA Chart: 11426                                  Latitude:         26° 24.8' N
USGS Quad:  FORT MYERS BEACH                       Longitude:        81° 53.9' 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.