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

                                                   PUBLICATION DATE:  05/01/1984
Station ID: 8663731                                SUPERCEDED DATE:   04/21/2003
Name:       BONNEAU FERRY, EAST BRANCH COOPER RIVER           
            SOUTH CAROLINA
NOAA Chart: 11527                                  Latitude:         33°  4.3' N
USGS Quad:  KITTREDGE                              Longitude:        79° 53.0' W


To reach the tidal bench marks from the intersection of Route 17A and Highway 6
in Moncks Corner, proceed NE on 17A for 1.2 miles (1.9 km), NE on US Route 52
for 1.9 miles (3.1 km) on Route 402 for 9.1 miles (14.6 km), right on dirt road
leading to main gates of Bonneau Ferry Conference Center, continue 4.2 miles
(6.8 km) past center, then left on dirt road at main office for 0.15 miles (0.24
km) along right bend to loading dock.  The bench marks are near dirt road
leading from main office to dock and the tide gage and staff were on the loading
dock.


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


                 PRIMARY BENCH MARK STAMPING:  3731 A 1982

MONUMENTATION:           Survey Disk                               VM#:     4013
AGENCY:                                                            PID#:  DD1229
SETTING CLASSIFICATION:  Stainless Steel Rod


The bench mark is 91.0 feet (27.7 m) east of centerline of dirt road leading
towards dock, 29.8 feet (9.1 m) north of center of concrete boat ramp, 9.6 feet
(2.9 m) south of south face of 3.0 feet (0.9 m) diameter oak tree, and 1.2 feet
(0.4 m) WSW of witness post with sign.  The bench mark is 0.5 foot (0.2 m) below
ground level, crimped to a stainless steel rod driven 28 feet (9 m) to refusal,
and encased in a 5-inch PVC pipe and concrete kickblock.



                         BENCH MARK STAMPING:  3731 B 1982

MONUMENTATION:           Survey Disk                               VM#:     4014
AGENCY:                                                            PID#:  DD1230
SETTING CLASSIFICATION:  Concrete Mounument


The bench mark is set flush in a concrete monument 3 feet (0.9 m) deep, 206.4
feet (62.9 m) south of Bench Mark 3731 C 1982, 195.5 feet (59.6 m) SE of SE
corner of brick house, 29.9 feet (9.1 m) SE of east face of large oak tree, 21.6
feet (6.6 m) NNE of north face of single magnolia tree and 0.1 foot (0.03 m)
below ground.

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

                                                   PUBLICATION DATE:  05/01/1984
Station ID: 8663731                                SUPERCEDED DATE:   04/21/2003
Name:       BONNEAU FERRY, EAST BRANCH COOPER RIVER           
            SOUTH CAROLINA
NOAA Chart: 11527                                  Latitude:         33°  4.3' N
USGS Quad:  KITTREDGE                              Longitude:        79° 53.0' W


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


                         BENCH MARK STAMPING:  3731 C 1982

MONUMENTATION:           Survey Disk                               VM#:     4015
AGENCY:                                                            PID#:  DD1231
SETTING CLASSIFICATION:  Concrete Monument


The bench mark is set flush in a concrete monument 3 feet (0.9 m) deep, 141.9
feet (43.3 m) NNE of NE corner of brick house, 22.0 feet (6.7 m) SW of edge of
drainage creek, 14.9 feet (4.5 m) SE of south face of 2.0 feet (0.6 m) diameter
pine tree, and 0.1 foot (0.03 m) above ground level.



                         BENCH MARK STAMPING:  3731 D 1982

MONUMENTATION:           Survey Disk                               VM#:     4016
AGENCY:                                                            PID#:  DD1227
SETTING CLASSIFICATION:  Concrete Monument


The bench mark is set flush in a concrete monument 3 feet (0.9 m) deep, 218.9
feet (66.7 m) NNE of Bench Mark 3731 E 1982, 32.2 feet (9.8 m) north of north
face of cedar tree at intersection of dirt roads, 5.98 feet (1.8 m) NW of guy
wire anchor, and 5.6 feet (1.7 m) NE of power pole with meter Box #46-539-311
and witness sign.



                         BENCH MARK STAMPING:  3731 E 1982

MONUMENTATION:           Survey Disk                               VM#:     4017
AGENCY:                                                            PID#:  DD1228
SETTING CLASSIFICATION:  Stainless Steel Rod


The bench mark is 106.1 feet (32.3 m) WSW of SW corner of brick house, 18.3 feet
(5.6 m) SSW of south face of 3.0 feet (0.9 m) diameter oak tree, 17.9 feet (5.5
m) west of centerline of dirt road leading towards dock, and 14.2 feet (4.3 m)
NNW of north face of 3.0 feet (0.9 m) diameter oak tree.  The bench mark is 0.2
foot (0.06 m) below ground level, 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:  05/01/1984
Station ID: 8663731                                SUPERCEDED DATE:   04/21/2003
Name:       BONNEAU FERRY, EAST BRANCH COOPER RIVER           
            SOUTH CAROLINA
NOAA Chart: 11527                                  Latitude:         33°  4.3' N
USGS Quad:  KITTREDGE                              Longitude:        79° 53.0' W


                            T I D A L   D A T U M S 


Tidal datums at BONNEAU FERRY, EAST BRANCH COOPER RIVER based on:

     LENGTH OF SERIES:      3 MONTHS
     TIME PERIOD:           JULY-SEPTEMBER 1982
     TIDAL EPOCH:           1960-1978
     CONTROL TIDE STATION:  8665530 CHARLESTON, SC


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

     HIGHEST OBSERVED WATER LEVEL (06/18/1982)         =   5.39
     MEAN HIGHER HIGH WATER                     MHHW   =   3.70
     MEAN HIGH WATER                            MHW    =   3.45
     MEAN TIDE LEVEL                            MTL    =   1.90
     MEAN LOW WATER                             MLW    =   0.34
     MEAN LOWER LOW WATER                       MLLW   =   0.00
     LOWEST  OBSERVED WATER LEVEL (08/01/1982)         =  -1.19

North American Vertical Datum (NAVD88)

Bench Mark Elevation Information                In FEET above:

     Stamping or Designation                    MLLW        MHW

     3731 A 1982                                 8.88      5.43
     3731 B 1982                                 7.78      4.33
     3731 C 1982                                 7.72      4.27
     3731 D 1982                                 7.99      4.54
     3731 E 1982                                 5.36      1.91


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

                                                   PUBLICATION DATE:  05/01/1984
Station ID: 8663731                                SUPERCEDED DATE:   04/21/2003
Name:       BONNEAU FERRY, EAST BRANCH COOPER RIVER           
            SOUTH CAROLINA
NOAA Chart: 11527                                  Latitude:         33°  4.3' N
USGS Quad:  KITTREDGE                              Longitude:        79° 53.0' 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.