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

                                                                                
Station ID: 8664022                         PUBLICATION DATE:  04/21/2003
Name:       GEN. DYNAMICS PIER, COOPER R.                     
            SC
NOAA Chart: 11527                           Latitude:   33°  0.5' N (  33.00830)
USGS Quad:  KITTREDGE                       Longitude:  79° 55.4' W ( -79.92330)


To reach the tidal bench marks from the junction of U.S. Highway 52 and U.S.
Highway 176 at Goose Creek, proceed SE on Red Bank Road (County Road S-8-29) for
10.9 km (6.8 mi) to Bushy Park Road (Country Road S-8-503), (also 6.0 km (3.7
mi) east along Red Bank Road from its intersection with N. Rhett Avenue
extencded), thence 5.6 km (3.5 mi) northerly along Bushy Park Road to the
entrance of the former General Dynamics Corporation now operated by the Marine
Energy Systems Corporation (MESC) at 2040 Bushy Park Road.  Thence 0.72 km (0.45
mi) east through the security gate along the road to the north side of the barge
slip.  The primary bench mark is located in the vicinity of the barge slip and
the tide gage pier.  The tide gage and staff were located on a pier just north
of the barge slip.


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


                 PRIMARY BENCH MARK STAMPING:  4022 A 1976
                         DESIGNATION:          866 4022 A TIDAL

MONUMENTATION:           Tidal Station disk                    VM#:          606
AGENCY:                  National Ocean Survey (NOS)           IDB PID#:  DD1303
SETTING CLASSIFICATION:  Copper-clad steel rod                 OPUS PID:        
LATITUDE:   33°  0.5' N (  33.00830)          LONGITUDE:  79° 55.3' W ( -79.92170)


The primary bench mark is a disk located in the vicinity of the barge slip and
the tide gage pier, 15.06 m (49.4 ft) SW of the SW corner of the wooden pier,
7.32 m (24.0 ft) north of the top of the rock bank at the barge slip, and 0.3 m
(1.0 ft) east of utility pole SPSJ 1-70 KD.  The bench mark is set at ground
level, crimped to a copper-clad steel rod driven 4.91 m (16.1 ft) 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

                                                                                
Station ID: 8664022                         PUBLICATION DATE:  04/21/2003
Name:       GEN. DYNAMICS PIER, COOPER R.                     
            SC
NOAA Chart: 11527                           Latitude:   33°  0.5' N (  33.00830)
USGS Quad:  KITTREDGE                       Longitude:  79° 55.4' W ( -79.92330)


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


                         BENCH MARK STAMPING:  4022 C 1976
                         DESIGNATION:          866 4022 C TIDAL

MONUMENTATION:           Tidal Station disk                    VM#:          608
AGENCY:                  National Ocean Survey (NOS)           IDB PID#:  DD1301
SETTING CLASSIFICATION:  Copper-clad steel rod                 OPUS PID:        
LATITUDE:   33°  0.6' N (  33.01000)          LONGITUDE:  79° 55.5' W ( -79.92500)


The bench mark is a disk located near the NE corner of the large green aluminum
sided sub-assembly building, 11.70 m (38.4 ft) south of the gravel road around
the building, 5.64 m (18.5 ft) NW of the NE corner of the building, and 2.35 m
(7.7 ft) north of the north face of the building at the most easterly entrance
on the north side of the building.  The bench mark is set at ground level,
crimped to a copper-clad steel rod driven 3.69 m (12.1 ft) to refusal, and
encased in a 4-inch PVC pipe and concrete kickblock.



                         BENCH MARK STAMPING:  4022 F 1982
                         DESIGNATION:          866 4022 F

MONUMENTATION:           Bench Mark disk                       VM#:          609
AGENCY:                  National Ocean Service (NOS)          IDB PID#:        
SETTING CLASSIFICATION:  Concrete slab                         OPUS PID:        
LATITUDE:   33°  0.6' N (  33.01000)          LONGITUDE:  79° 55.6' W ( -79.92670)


The bench mark is a disk set flush in the NE corner of a 4 m x 7 m (13.1 ft x 23
ft) concrete slab near the NE corner of the north wing of a large green aluminum
sided sub-assembly building, 31.85 m (104.5 ft) NW of the NW corner of the most
northwesterly concrete slab with a 5-inch PVC pipe filled with concrete, 11.52 m
(37.8 ft) north of the NE corner of the north wing of the building, 7.83 m (25.7
ft) SE of the centerline of a dirt road, and 0.70 m (2.3 ft) south of the north
corner of a concrete base supporting liquid oxygen tank.

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

                                                                                
Station ID: 8664022                         PUBLICATION DATE:  04/21/2003
Name:       GEN. DYNAMICS PIER, COOPER R.                     
            SC
NOAA Chart: 11527                           Latitude:   33°  0.5' N (  33.00830)
USGS Quad:  KITTREDGE                       Longitude:  79° 55.4' W ( -79.92330)


                            T I D A L   D A T U M S 


Tidal datums at GEN. DYNAMICS PIER, COOPER R. based on:

     LENGTH OF SERIES:      16 Years
     TIME PERIOD:           January 1977 - December 1992
     TIDAL EPOCH:           1983-2001
     CONTROL TIDE STATION:  8665530 CHARLESTON, COOPER RIVER ENTRANCE


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

     HIGHEST OBSERVED WATER LEVEL (09/04/1979)         =  2.447
     MEAN HIGHER HIGH WATER                     MHHW   =  1.477
     MEAN HIGH WATER                            MHW    =  1.390
     MEAN SEA LEVEL                             MSL    =  0.792
     MEAN TIDE LEVEL                            MTL    =  0.727
     North American Vertical Datum              NAVD88 =  0.665
     MEAN LOW WATER                             MLW    =  0.063
     MEAN LOWER LOW WATER                       MLLW   =  0.000
     LOWEST  OBSERVED WATER LEVEL (01/28/1986)         = -0.756

North American Vertical Datum (NAVD88)

Bench Mark Elevation Information                In METERS above:

     Stamping or Designation                    MLLW        MHW

     4022 A 1976                                 2.380    0.990
     4022 C 1976                                 2.835    1.445
     4022 F 1982                                 3.121    1.731


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

                                                                                
Station ID: 8664022                         PUBLICATION DATE:  04/21/2003
Name:       GEN. DYNAMICS PIER, COOPER R.                     
            SC
NOAA Chart: 11527                           Latitude:   33°  0.5' N (  33.00830)
USGS Quad:  KITTREDGE                       Longitude:  79° 55.4' W ( -79.92330)


                             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 NGS's Integrated Data Base (IDB PID)
provides geodetic datum based on traditionally leveled and bluebooked ties to
the National Spatial Reference System(NSRS) https://www.ngs.noaa.gov/datasheets/.
The NGS Online Positioning User Service (OPUS PID) provides geodetic datum based
on GPS position & tie it to the NSRS https://www.ngs.noaa.gov/OPUS/.

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.