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

                                                   PUBLICATION DATE:  05/01/1987
Station ID: 8722334                                SUPERCEDED DATE:   04/21/2003
Name:       NORTH FORK, ST. LUCIE RIVER                       
            FLORIDA
NOAA Chart: 11474                                  Latitude:         27° 14.6' N
USGS Quad:  PALM CITY                              Longitude:        80° 18.8' W


To reach the tidal bench marks from the NW end of the U.S. Highway 1 bridge over
the St. Lucie River in Stuart, proceed 4.3 miles (6.9 km) north on U.S. Highway
1 to Westmoreland Boulevard (entrance for the Sandpiper Bay Resort), proceed 1.3
miles (2.1 km) west on Westmoreland Boulevard to Pine Valley Road, then proceed
1.4 miles (2.3 km) south on Pine Valley Road to the St. Lucie Hilton Country
Club Marina.  The bench marks are on the Hilton Marina property, along the
concrete walk and seawall.  The tide gage and staff were on the Hilton Marina
pier.


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


                 PRIMARY BENCH MARK STAMPING:  NO 2 1972

MONUMENTATION:           Survey Disk                               VM#:     5437
AGENCY:                                                            PID#:  AF6948
SETTING CLASSIFICATION:  Concrete Seawall


The bench mark is set flush in the top of the concrete seawall, 60 feet (18 m)
SW of the SW corner of the dock master's office, 2.6 feet (0.8 m) NE of the SW
corner of the seawall and boat ramp, 2.0 feet (0.6 m) SW of a 4-inch pipe base
supporting a Standard Oil sign, and 1.8 feet (0.5 m) east of the east wall of
the boat ramp.



                         BENCH MARK STAMPING:  NO 3 1972

MONUMENTATION:           Survey Disk                               VM#:     5438
AGENCY:                                                            PID#:  AF6949
SETTING CLASSIFICATION:  Concrete Seawall


The bench mark is set flush in the top of the concrete seawall, 162 feet (49 m)
west of the SW corner of the dock master's office, and 0.8 foot (0.2 m) NE of
the SW corner of the seawall and boat ramp.

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

                                                   PUBLICATION DATE:  05/01/1987
Station ID: 8722334                                SUPERCEDED DATE:   04/21/2003
Name:       NORTH FORK, ST. LUCIE RIVER                       
            FLORIDA
NOAA Chart: 11474                                  Latitude:         27° 14.6' N
USGS Quad:  PALM CITY                              Longitude:        80° 18.8' W


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


                         BENCH MARK STAMPING:  NO 4 1972

MONUMENTATION:           Survey Disk                               VM#:     5439
AGENCY:                                                            PID#:  AF6946
SETTING CLASSIFICATION:  Concrete Dock


The bench mark is set flush in the concrete dock of the St. Lucie Hilton Country
Club, just south of the tennis courts, 231.5 feet (70.6 m) west of the NE corner
of the dock, 109.5 feet (33.4 m) east of the NW corner of the dock, 9.5 feet
(2.9 m) north of the south edge of the dock, and 0.5 foot (0.2 m) south of the
north edge of the dock.



                         BENCH MARK STAMPING:  NO 5 1972

MONUMENTATION:           Survey Disk                               VM#:     5440
AGENCY:                                                            PID#:  AF6945
SETTING CLASSIFICATION:  Concrete Dock


The bench mark is set flush in the concrete dock of the St. Lucie Hilton Country
Club Marina, just south of the tennis courts, 180.3 feet (60.0 m) east of Bench
Mark N0 4 1972, 51.2 feet (15.6 m) east of the NE corner of the dock, 9.5 feet
(2.9 m) north of the south edge of the dock, and 0.4 foot (0.1 m) south of the
north edge of the dock.

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

                                                   PUBLICATION DATE:  05/01/1987
Station ID: 8722334                                SUPERCEDED DATE:   04/21/2003
Name:       NORTH FORK, ST. LUCIE RIVER                       
            FLORIDA
NOAA Chart: 11474                                  Latitude:         27° 14.6' N
USGS Quad:  PALM CITY                              Longitude:        80° 18.8' W


                            T I D A L   D A T U M S 


Tidal datums at NORTH FORK, ST. LUCIE RIVER based on:

     LENGTH OF SERIES:      5 MONTHS
     TIME PERIOD:           AUGUST-DECEMBER 1972
     TIDAL EPOCH:           1960-1978
     CONTROL TIDE STATION:  8722371 SEWALL POINT


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

     HIGHEST OBSERVED WATER LEVEL (10/22/1972)         =   2.64
     MEAN HIGHER HIGH WATER                     MHHW   =   1.23
     MEAN HIGH WATER                            MHW    =   1.12
     MEAN TIDE LEVEL                            MTL    =   0.63
     MEAN LOW WATER                             MLW    =   0.13
     MEAN LOWER LOW WATER                       MLLW   =   0.00
     LOWEST  OBSERVED WATER LEVEL (08/02/1972)         =  -0.44

North American Vertical Datum (NAVD88)

Bench Mark Elevation Information                In FEET above:

     Stamping or Designation                    MLLW        MHW

     NO 2 1972                                   5.03      3.91
     NO 3 1972                                   5.01      3.89
     NO 4 1972                                   4.34      3.22
     NO 5 1972                                   4.31      3.19


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

                                                   PUBLICATION DATE:  05/01/1987
Station ID: 8722334                                SUPERCEDED DATE:   04/21/2003
Name:       NORTH FORK, ST. LUCIE RIVER                       
            FLORIDA
NOAA Chart: 11474                                  Latitude:         27° 14.6' N
USGS Quad:  PALM CITY                              Longitude:        80° 18.8' 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.