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

                                                   PUBLICATION DATE:  11/21/1990
Station ID: 8664545                                SUPERCEDED DATE:   04/21/2003
Name:       COX'S PIER, WANDO RIVER                           
            SOUTH CAROLINA
NOAA Chart: 11524                                  Latitude:         32° 55.6' N
USGS Quad:  CAINHOY                                Longitude:        79° 49.8' W


To reach the tidal bench marks fron the intersection of U.S. Highway 17 and
State Road 41, proceed NW on State Road 41 for 5.5 miles (8.9 km) to the
junction of State Roads S-8-98 and S-8-33 in Cainhoy, go east on State Road
S-8-33 for 0.05 mile (0.08 km) to State Road S-8-26, then 0.3 mile (0.5 km)
south on State Road S-8-26 to the Post Office in Wando.  The bench marks are at
the Post Office and along the shore.  The tide gage and staff were on the pier
behind the Cox residence, about 0.05 mile (0.08 km) SE of the Post Office.


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


                 PRIMARY BENCH MARK STAMPING:  4545 A 1976

MONUMENTATION:           Survey Disk                               VM#:     4061
AGENCY:                                                            PID#:  CJ0501
SETTING CLASSIFICATION:  Copper-clad Steel Rod


The bench mark is at the inshore end of the pier behind the Cox residence,  
33.3 feet (10.1 m) NNE of a power pole on the pier with spot lights on it,  
32.1 feet (9.8 m) NNE of the end of the pier, 28.5 feet (8.7 m) east of a
2.0-foot (0.6 m) diameter pecan tree, 20.8 feet (6.3 m) SE of a 1.5-foot    (0.5
m) diameter magnolia tree, 14.3 feet (4.4 m) west of the edge of the marsh, and
3.2 feet (1.0 m) west of a witness post with sign.  The bench mark is 1.8 feet
(0.5 m) below the ground, crimped to a copper-clad steel rod driven 22 feet (7
m) to refusal, and encased in a 4-inch PVC pipe and concrete kickblock.



                         BENCH MARK STAMPING:  4545 C 1976

MONUMENTATION:           Survey Disk                               VM#:     4062
AGENCY:                                                            PID#:  CJ0504
SETTING CLASSIFICATION:  Copper-clad Steel Rod


The bench mark is about 300 feet (91 m) south of the Post Office, 49.0 feet
(14.9 m) ESE of the SE corner of the porch of a one-story wood frome house with
brick foundation, 32.6 feet (9.9 m) SE of a 1.5-foot (0.5 m) diameter pecan tree
in the yard of a private residence, 11.7 feet (3.6 m) west of the center- line
of State Road S-8-26, 5.0 feet (1.5 m) north of the corner post of a wire link
fence, and 3.4 feet (1.0 m) north of power pole #177455. The bench mark is level
with the ground, crimped to a copper-clad steel rod driven 32 feet (10 m) to
refusal, and encased in a 4-inch PVC pipe and concrete kickblock.

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

                                                   PUBLICATION DATE:  11/21/1990
Station ID: 8664545                                SUPERCEDED DATE:   04/21/2003
Name:       COX'S PIER, WANDO RIVER                           
            SOUTH CAROLINA
NOAA Chart: 11524                                  Latitude:         32° 55.6' N
USGS Quad:  CAINHOY                                Longitude:        79° 49.8' W


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


                         BENCH MARK STAMPING:  4545 D 1976

MONUMENTATION:           Survey Disk                               VM#:     4063
AGENCY:                                                            PID#:  CJ0502
SETTING CLASSIFICATION:  Copper-clad Steel Rod


The bench mark is at the south end of State Road S-8-26 about 750 feet (229 m)
south of the Post Office, 150 feet (46 m) west of the end of State Road S-8-26,
14.1 feet (4.3 m) NW of a 2.5-foot (0.8 m) diameter oak tree, 7.9 feet (2.4 m)
south of the centerline of a dirt road, and 2.9 feet (0.9 m) SW of power pole
#188980.  The bench mark is level with the ground, crimped to a copper-clad
steel rod driven 27 feet (8 m) to refusal, and encased in a 4-inch PVC pipe and
concrete kickblock.



                         BENCH MARK STAMPING:  4545 E 1982

MONUMENTATION:           Survey Disk                               VM#:     4064
AGENCY:                                                            PID#:  CJ0500
SETTING CLASSIFICATION:  Stainless Steel Rod


The bench mark is at a power pole across the road from the Post Office, 125.4
feet (38.2 m) ENE of the NE corner of the Post Office, 108.1 feet (32.9 m) NNE
of power pole #34344, 88.7 feet (27.0 m) SE of State Road S-8-26, 2.5 feet   
(0.8 m) south of power pole #34306, and 1.0 foot (0.3 m) west of a witness post
with sign. The bench mark is level with the ground, crimped to a stainless steel
rod driven 32 feet (10 m) to refusal, and encased in a 5-inch PVC pipe and
concrete kickblock.

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

                                                   PUBLICATION DATE:  11/21/1990
Station ID: 8664545                                SUPERCEDED DATE:   04/21/2003
Name:       COX'S PIER, WANDO RIVER                           
            SOUTH CAROLINA
NOAA Chart: 11524                                  Latitude:         32° 55.6' N
USGS Quad:  CAINHOY                                Longitude:        79° 49.8' W


                            T I D A L   D A T U M S 


Tidal datums at COX'S PIER, WANDO RIVER based on:

     LENGTH OF SERIES:      12 MONTHS
     TIME PERIOD:           MAY 1988-APRIL 1989
     TIDAL EPOCH:           1960-1978
     CONTROL TIDE STATION:  8665530 CHARLESTON


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

     HIGHEST OBSERVED WATER LEVEL (06/01/1977)         =   8.46
     MEAN HIGHER HIGH WATER                     MHHW   =   6.65
     MEAN HIGH WATER                            MHW    =   6.34
     MEAN TIDE LEVEL                            MTL    =   3.27
     MEAN LOW WATER                             MLW    =   0.19
     MEAN LOWER LOW WATER                       MLLW   =   0.00
     LOWEST  OBSERVED WATER LEVEL (04/07/1989)         =  -2.50

North American Vertical Datum (NAVD88)

Bench Mark Elevation Information                In FEET above:

     Stamping or Designation                    MLLW        MHW

     4545 A 1976                                 8.56      2.22
     4545 C 1976                                17.94     11.60
     4545 D 1976                                16.05      9.71
     4545 E 1982                                18.66     12.32


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

                                                   PUBLICATION DATE:  11/21/1990
Station ID: 8664545                                SUPERCEDED DATE:   04/21/2003
Name:       COX'S PIER, WANDO RIVER                           
            SOUTH CAROLINA
NOAA Chart: 11524                                  Latitude:         32° 55.6' N
USGS Quad:  CAINHOY                                Longitude:        79° 49.8' 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.