U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
Datums Page                                                        Page  1 of  5

                                                                                
Station ID: 8662670                         PUBLICATION DATE:  03/09/2004
Name:       PLEASANT HILL LANDING, SANTEE RIVER               
            SC
NOAA Chart:                                 Latitude:   33° 14.7' N (  33.24500)
USGS Quad:  HONEY HILL                      Longitude:  79° 31.3' W ( -79.52170)


To reach the tidal bench marks from U.S. Highway 17 at McClellanville, proceed
north on U.S. Highway 17 for 9.5 km (5.9 mi) to State Road S-10-857, then turn
left and proceed west on State Road S-10-857 for 5.1 km (3.2 mi) to the end of
the paved road, then continue west on the dirt road for 2.4 km (1.5 mi), then
turn left and go 0.2 km (0.1 mi) to the Elmwood Ranger Station entrance, turn
right to the station and continue past the station for 0.6 km (0.4 mi) to Echaw
Road (Forest Route 204), then turn right onto Echaw Road and go 9.3 km (5.8 mi)
to the North Hampton Hunt Unit gate, go through the gate, then turn right and
proceed west on a clay bed road for 1.4 km (0.9 mi) to a fork, bear right and
proceed north on Forest Route 204 F for 0.3 km (0.2 mi) to the South Carolina
Gas and Electric right-of-way with a pumping station to the left, and continue
past the clearing for 1.1 km (0.7 mi) to Pleasant Hill Landing.  NOTE:  Access
to this site after a moderate rain usually requires a 4-wheel drive vehicle. 
The tidal bench marks are along the road leading to the landing.  The tide gage
and staff were on a pier just west of the boat ramp.


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


                 PRIMARY BENCH MARK STAMPING:  2670 A 1976
                         DESIGNATION:          866 2670 A

MONUMENTATION:           Tidal Station disk                    VM#:         3938
AGENCY:                  National Ocean Survey (NOS)           IDB PID#:        
SETTING CLASSIFICATION:  Copper clad steel rod                 OPUS PID:        
LATITUDE:   33° 14.7' N (  33.24500)          LONGITUDE:  79° 31.1' W ( -79.51830)


The primary bench mark is a disk located near the pier just west of the boat
ramp, 18.59 m (61.0 ft) WNW of the centerline of a dirt path leading to the
pier, 10.85 m (35.6 ft) west of a 0.61 m (2.0 ft) diameter hickory tree, 9.51 m
(31.2 ft) NE of a 0.3 m (1 ft) diameter pine tree, 5 m (16 ft) SSW of the edge
of the south bank of the river, and 4.48 m (14.7 ft) SW of a 0.46 m (1.5 ft)
diameter gum tree.  The bench mark is crimped to the top of a copper-clad steel
rod driven 12.2 m (40 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  5

                                                                                
Station ID: 8662670                         PUBLICATION DATE:  03/09/2004
Name:       PLEASANT HILL LANDING, SANTEE RIVER               
            SC
NOAA Chart:                                 Latitude:   33° 14.7' N (  33.24500)
USGS Quad:  HONEY HILL                      Longitude:  79° 31.3' W ( -79.52170)


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


                         BENCH MARK STAMPING:  2670 G 1982
                         DESIGNATION:          866 2670 G

MONUMENTATION:           Tidal Station disk                    VM#:         3939
AGENCY:                  National Ocean Survey (NOS)           IDB PID#:        
SETTING CLASSIFICATION:  Concrete monument                     OPUS PID:        
LATITUDE:   33° 14.7' N (  33.24500)          LONGITUDE:  79° 31.1' W ( -79.51830)


The bench mark is a disk set in a concrete monument along the west side of the
road leading to Pleasant Hill Landing, 74 m (244 ft) north of 2670 H 1982, 11.0
m (36.0 ft) WNW of the center of the rock paved parking area, 8.99 m (29.5 ft)
east of a metal double trash receptacle, 5.49 m (18.0 ft) north of a 1.5-foot
(0.5 m) diameter pine tree, 0.76 m (2.5 ft) WNW of the center of a wooden guard
rail, and 6 cm (0.2 ft) above ground level.



                         BENCH MARK STAMPING:  2670 H 1982
                         DESIGNATION:          866 2670 H

MONUMENTATION:           Tidal Station disk                    VM#:         3940
AGENCY:                  National Ocean Survey (NOS)           IDB PID#:        
SETTING CLASSIFICATION:  Concrete monument                     OPUS PID:        
LATITUDE:   33° 14.7' N (  33.24500)          LONGITUDE:  79° 31.1' W ( -79.51830)


The bench mark is a disk set in a concrete monument along the west side of the
road leading to Pleasant Hill Landing, 18.47 m (60.6 ft) SSE of a 0.40 m (1.3
ft) diameter metal drain pipe, 8.38 m (27.5 ft) WSW of the centerline of the
dirt road, 1.80 m (5.9 ft) SSE of a 0.37 m (1.2 ft) diameter pine tree, 0.40 m
(1.3 ft) ENE of a metal witness post with sign, and 9 cm (0.3 ft) below ground
level.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  3 of  5

                                                                                
Station ID: 8662670                         PUBLICATION DATE:  03/09/2004
Name:       PLEASANT HILL LANDING, SANTEE RIVER               
            SC
NOAA Chart:                                 Latitude:   33° 14.7' N (  33.24500)
USGS Quad:  HONEY HILL                      Longitude:  79° 31.3' W ( -79.52170)


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


                         BENCH MARK STAMPING:  2670 J 1982
                         DESIGNATION:          866 2670 J

MONUMENTATION:           Tidal Station disk                    VM#:         3941
AGENCY:                  National Ocean Survey (NOS)           IDB PID#:        
SETTING CLASSIFICATION:  Concrete monument                     OPUS PID:        
LATITUDE:   33° 14.7' N (  33.24500)          LONGITUDE:  79° 31.1' W ( -79.51830)


The bench mark is a disk set in a concrete monument along the west side of the
road leading to Pleasant Hill Landing, 77.57 m (254.5 ft) north of 2670 K 1982,
6.92 m (22.7 ft) west of the centerline of the dirt road, 6.77 m (22.2 ft) south
of the 0.37 m (1.2 ft) diameter gum tree, 0.88 m (2.9 ft) NNW of a metal witness
post with sign, and 6 cm (0.2 ft) above ground level.



                         BENCH MARK STAMPING:  2670 K 1982
                         DESIGNATION:          866 2670 K

MONUMENTATION:           Tidal Station disk                    VM#:         3942
AGENCY:                  National Ocean Survey (NOS)           IDB PID#:        
SETTING CLASSIFICATION:  Concrete monument                     OPUS PID:        
LATITUDE:   33° 14.7' N (  33.24500)          LONGITUDE:  79° 31.1' W ( -79.51830)


The bench mark is a disk set in a concrete monument along the east side of the
road leading to Pleasant Hill Landing, 7.83 m (25.7 ft) ESE of the centerline of
the dirt road, 1.83 m (6.0 ft) SW of a 0.61 m (2.0 ft) diameter pine tree, 1.71
m (5.6 ft) NNE of a 0.37 m (1.2 ft) diameter pine tree, 0.40 m (1.3 ft)  west of
a metal witness post with sign, and level with the ground.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  4 of  5

                                                                                
Station ID: 8662670                         PUBLICATION DATE:  03/09/2004
Name:       PLEASANT HILL LANDING, SANTEE RIVER               
            SC
NOAA Chart:                                 Latitude:   33° 14.7' N (  33.24500)
USGS Quad:  HONEY HILL                      Longitude:  79° 31.3' W ( -79.52170)


                            T I D A L   D A T U M S 


Tidal datums at PLEASANT HILL LANDING, SANTEE RIVER based on:

     LENGTH OF SERIES:      3 MONTHS
     TIME PERIOD:           May 1977 - July 1977
     TIDAL EPOCH:           1983-2001
     CONTROL TIDE STATION:  8662799 US HIGHWAY 17, SOUTH SANTEE RIVER


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

     MEAN HIGHER HIGH WATER                     MHHW   =  0.805
     MEAN HIGH WATER                            MHW    =  0.745
     MEAN TIDE LEVEL                            MTL    =  0.394
     MEAN SEA LEVEL                             MSL    =  0.390
     MEAN LOW WATER                             MLW    =  0.043
     MEAN LOWER LOW WATER                       MLLW   =  0.000

North American Vertical Datum (NAVD88)

Bench Mark Elevation Information                In METERS above:

     Stamping or Designation                    MLLW        MHW

     2670 A 1976                                 6.697    5.952
     2670 G 1982                                 4.845    4.100
     2670 H 1982                                 3.791    3.046
     2670 J 1982                                 3.753    3.008
     2670 K 1982                                 5.257    4.512


                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  5 of  5

                                                                                
Station ID: 8662670                         PUBLICATION DATE:  03/09/2004
Name:       PLEASANT HILL LANDING, SANTEE RIVER               
            SC
NOAA Chart:                                 Latitude:   33° 14.7' N (  33.24500)
USGS Quad:  HONEY HILL                      Longitude:  79° 31.3' W ( -79.52170)


                             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.