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

                                                                                
Station ID: 8661139                         PUBLICATION DATE:  02/26/2004
Name:       BUCKSPORT, WACCAMAW RIVER                         
            SC
NOAA Chart: 11535                           Latitude:   33° 38.8' N (  33.64670)
USGS Quad:  BUCKSVILLE                      Longitude:  79°  5.7' W ( -79.09500)


To reach the tidal bench marks from the junction of U.S. Highway 501 and State
Highway 378 (SC 378) in Conway, proceed east on SC 378 for 0.3 km (0.2 mi) to
U.S. Highway 701, turn right and go south on U.S. Highway 701 for 18.3 km (11.4
mi)  to State Road S 26 48, turn left and go east on S 26 48 for 5.1 km (3.2 mi)
to the roads end at Bucksport Marina.  The bench marks are located on the marina
grounds.  The tide gage and staff were located 0.2 km (0.1 mi) SE of the roads
end at the large tin boat shed.


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


                 PRIMARY BENCH MARK STAMPING:  BUCKS NO 7 1975
                         DESIGNATION:          866 1139 TIDAL BUCKS 7

MONUMENTATION:           Tidal Station disk                    VM#:          580
AGENCY:                  National Ocean Survey (NOS)           IDB PID#:  DD2368
SETTING CLASSIFICATION:  Copper-clad steel rod                 OPUS PID#: DD2368
LATITUDE:   33° 39.0' N (  33.65000)          LONGITUDE:  79°  5.8' W ( -79.09670)


The primary bench mark is a disk located at Bucksport Marina, 62.27 m (204.3 ft)
NW of bench mark BUCKS NO 6 1975, 40.84 m (134.0 ft) ENE of the SE corner of an
abandoned wood shingle house with brick foundation, 14.81 m (48.6 ft) NW of a 1
m (3 ft) diameter oak tree, 9.85 m (32.3 ft) NE of the centerline of the dirt
road extension of S 26 48, and 1.13 m (3.7 ft) NE of utility pole #275. The
bench mark is set 12 cm (0.4 ft) below ground, crimped to a copper-clad steel
rod driven an unspecified depth 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: 8661139                         PUBLICATION DATE:  02/26/2004
Name:       BUCKSPORT, WACCAMAW RIVER                         
            SC
NOAA Chart: 11535                           Latitude:   33° 38.8' N (  33.64670)
USGS Quad:  BUCKSVILLE                      Longitude:  79°  5.7' W ( -79.09500)


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


                         BENCH MARK STAMPING:  BUCKS NO 6 1975
                         DESIGNATION:          866 1139 TIDAL BUCKS 6

MONUMENTATION:           Tidal Station disk                    VM#:          582
AGENCY:                  National Ocean Survey (NOS)           IDB PID#:  DD2369
SETTING CLASSIFICATION:  Copper-clad steel rod                 OPUS PID:        
LATITUDE:   33° 39.0' N (  33.65000)          LONGITUDE:  79°  5.7' W ( -79.09500)


The bench mark is a disk located at Bucksport Marina, 53.89 m (176.8 ft) west of
the southernost of two "Phillips 66" signs, 23.20 m (76.1 ft) east of the
centerline of the dirt road extension of S 26 48, 11.22 m (36.8 ft) north of the
centerline of a dirt road leading to a tin boat wharf, and 2.4 m (5.7 ft) north
of utility pole 2X3. The bench mark is crimped to a copper-clad steel rod driven
an unspecified depth to refusal, and encased in a 4-inch PVC pipe and concrete
kickblock.



                         BENCH MARK STAMPING:  1139 A 1982
                         DESIGNATION:          866 1139 A TIDAL

MONUMENTATION:           Tidal Station disk                    VM#:          583
AGENCY:                  National Ocean Survey (NOS)           IDB PID#:  DD2370
SETTING CLASSIFICATION:  Concrete monument                     OPUS PID:        
LATITUDE:   33° 39.0' N (  33.65000)          LONGITUDE:  79°  5.7' W ( -79.09500)


The bench mark is set in the top of a concrete monument at Bucksport Marina,
54.86 m (180.0 ft) east of bench mark BUCKS NO 6 1975, 23.59 m (77.4 ft) north
of a double trunk oak tree, 20.42 m (67.0 ft) west of the river edge, 12.19 m
(40.0 ft) east of the centerline of the dirt road leading from the boat ramp to
the marina store, and 0.52 m (1.7 ft) SE of the SE face of the concrete base of
the southernmost of two Phillips 66 signs.

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

                                                                                
Station ID: 8661139                         PUBLICATION DATE:  02/26/2004
Name:       BUCKSPORT, WACCAMAW RIVER                         
            SC
NOAA Chart: 11535                           Latitude:   33° 38.8' N (  33.64670)
USGS Quad:  BUCKSVILLE                      Longitude:  79°  5.7' W ( -79.09500)


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


                         BENCH MARK STAMPING:  1139 C 1982
                         DESIGNATION:          866 1139 TIDAL C

MONUMENTATION:           Tidal Station disk                    VM#:          584
AGENCY:                  National Ocean Survey (NOS)           IDB PID#:  DD2366
SETTING CLASSIFICATION:  Stainless steel rod                   OPUS PID#: DD2366
LATITUDE:   33° 39.0' N (  33.65000)          LONGITUDE:  79°  5.8' W ( -79.09670)


The bench mark is a disk located at Bucksport Marina, 56.88 m (186.6 ft) SW of
the SW face of the two-story garage and marina store, 12.44 m (40.8 ft) SE of
the centerline of a road leading around the north side of the garage and marina
store, 7.86 m (25.8 ft) NE of the centerline of S 26 48, and 0.49 m (1.6 ft) NW
of a pole marked 9283.  The bench mark is crimped to a stainless steel rod
driven 7.6 m (25 ft)  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  4 of  5

                                                                                
Station ID: 8661139                         PUBLICATION DATE:  02/26/2004
Name:       BUCKSPORT, WACCAMAW RIVER                         
            SC
NOAA Chart: 11535                           Latitude:   33° 38.8' N (  33.64670)
USGS Quad:  BUCKSVILLE                      Longitude:  79°  5.7' W ( -79.09500)


                            T I D A L   D A T U M S 


Tidal datums at BUCKSPORT, WACCAMAW RIVER based on:

     LENGTH OF SERIES:      15 YEARS
     TIME PERIOD:           January 1977 - December 1991
     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 (03/27/1983)         =  1.821
     MEAN HIGHER HIGH WATER                     MHHW   =  0.746
     MEAN HIGH WATER                            MHW    =  0.710
     MEAN SEA LEVEL                             MSL    =  0.433
     MEAN TIDE LEVEL                            MTL    =  0.381
     North American Vertical Datum              NAVD88 =  0.151
     MEAN LOW WATER                             MLW    =  0.052
     MEAN LOWER LOW WATER                       MLLW   =  0.000
     LOWEST  OBSERVED WATER LEVEL (03/17/1983)         = -0.767

North American Vertical Datum (NAVD88)

Bench Mark Elevation Information                In METERS above:

     Stamping or Designation                    MLLW        MHW

     BUCKS NO 7 1975                             4.098    3.388
     BUCKS NO 6 1975                             3.796    3.086
     1139 A 1982                                 2.102    1.392
     1139 C 1982                                 4.413    3.703


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

                                                                                
Station ID: 8661139                         PUBLICATION DATE:  02/26/2004
Name:       BUCKSPORT, WACCAMAW RIVER                         
            SC
NOAA Chart: 11535                           Latitude:   33° 38.8' N (  33.64670)
USGS Quad:  BUCKSVILLE                      Longitude:  79°  5.7' W ( -79.09500)


                             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.