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Bench Mark Sheet for 8661703, SANDY ISLAND, THOROUGHFARE CREEK SC

Superseded Epoch

Large map location marker Station Location
Small red map location marker Published bench mark
Small blue map location marker Unpublished bench mark

Bench mark positions only appear on the map if their coordinates in the CO-OPS database are at the precision of degrees/minutes/seconds/and tenths of seconds. If the coordinates are less precise, the mark will not appear.

Printable version

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

                                                                                
Station ID: 8661703                         PUBLICATION DATE:  06/28/2004
Name:       SANDY ISLAND, THOROUGHFARE CREEK                  
            SC
NOAA Chart: 11535                           Latitude:   33° 30.4' N (  33.50670)
USGS Quad:  PLANTERSVILLE                   Longitude:  79°  8.7' W ( -79.14500)


To reach the tidal bench marks from Bucksport, proceed by boat south on the
Waccamaw River for approximately 19 km (12 statute mi) to the entrance of
Thoroughfare Creek, then west on Thoroughfare Creek for 0.5 km (0.3 mi) to the
low, wooded dike running along the east side of the southernmost point of Sandy
Island.  The bench marks are along the wooded dike, between the southernmost
point and a small stream meandering into the island to the west of the point. 
The tide gage and staff were on a small dock connected to a cypress tree.


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


                 PRIMARY BENCH MARK STAMPING:  SANDY NO 1 1974
                         DESIGNATION:          866 1703 SANDY NO 1

MONUMENTATION:           Bench Mark disk                       VM#:         3856
AGENCY:                  US Coast & Geodetic Survey
                         (USC&GS)                                 IDB PID#:        
SETTING CLASSIFICATION:  Unspecified steel rod                 OPUS PID:        
LATITUDE:   33° 30.4' N (  33.50670)          LONGITUDE:  79°  8.8' W ( -79.14670)


The primary bench mark is a disk located 9 m (30 ft) east of the east creek
bank, 3.0 m (9.7 ft) NNE of a 1 m (2 ft) diameter cypress tree, 3.0 m (9.7 ft)
east of another 1 m (2 ft) diameter cypress tree, and 1 m (2 ft) west of a steel
witness post.  The bench mark is set 0.15 m (0.5 ft) above grade, crimped to the
top of an unspecified steel rod driven an unknown depth.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  2 of  5

                                                                                
Station ID: 8661703                         PUBLICATION DATE:  06/28/2004
Name:       SANDY ISLAND, THOROUGHFARE CREEK                  
            SC
NOAA Chart: 11535                           Latitude:   33° 30.4' N (  33.50670)
USGS Quad:  PLANTERSVILLE                   Longitude:  79°  8.7' W ( -79.14500)


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


                         BENCH MARK STAMPING:  SANDY NO 2 1974
                         DESIGNATION:          866 1703 SANDY NO 2

MONUMENTATION:           Bench Mark disk                       VM#:         3857
AGENCY:                  US Coast & Geodetic Survey
                         (USC&GS)                                 IDB PID#:        
SETTING CLASSIFICATION:  Unspecified steel rod                 OPUS PID:        
LATITUDE:   33° 30.4' N (  33.50670)          LONGITUDE:  79°  8.8' W ( -79.14670)


The bench mark is a disk located 14.08 m (46.2 ft) north of bench mark SANDY NO
1 1974, 7.19 m (23.6 ft) west of bench mark SANDY NO 4 1974, 5 m (15 ft) east of
the east creek bank, and 0.52 m (1.7 ft) west of a steel witness post.  The
bench mark is crimped to the top of an unspecified steel rod driven an unknown
depth.



                         BENCH MARK STAMPING:  SANDY NO 3 1974
                         DESIGNATION:          866 1703 SANDY NO 3

MONUMENTATION:           Bench Mark disk                       VM#:         3858
AGENCY:                  US Coast & Geodetic Survey
                         (USC&GS)                                 IDB PID#:        
SETTING CLASSIFICATION:  Unspecified steel rod                 OPUS PID:        
LATITUDE:   33° 30.4' N (  33.50670)          LONGITUDE:  79°  8.8' W ( -79.14670)


The bench mark is a disk located 9 m (30 ft) east of the east creek bank, 4.57 m
(15.0 ft) SE of bench mark SANDY NO 2 1974, and 0.82 m (2.7 ft) NNW of a steel
witness post.  The bench mark is set 0.15 m (0.5 ft) above grade, crimped to the
top of an unspecified steel rod  driven an unknown depth.

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

                                                                                
Station ID: 8661703                         PUBLICATION DATE:  06/28/2004
Name:       SANDY ISLAND, THOROUGHFARE CREEK                  
            SC
NOAA Chart: 11535                           Latitude:   33° 30.4' N (  33.50670)
USGS Quad:  PLANTERSVILLE                   Longitude:  79°  8.7' W ( -79.14500)


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


                         BENCH MARK STAMPING:  SANDY NO 4 1974
                         DESIGNATION:          866 1703 SANDY NO 4

MONUMENTATION:           Bench Mark disk                       VM#:         3859
AGENCY:                  US Coast & Geodetic Survey
                         (USC&GS)                                 IDB PID#:        
SETTING CLASSIFICATION:  Unspecified steel rod                 OPUS PID:        
LATITUDE:   33° 30.4' N (  33.50670)          LONGITUDE:  79°  8.8' W ( -79.14670)


The bench mark is a disk located 12 m (40 ft) east of the east creek bank, 8 m
(26 ft) ENE of bench mark SANDY NO 3 1974, 2.44 m (8.0 ft) north of a twin oak
and cypress tree, 1.74 m (5.7 ft) west of a 0.3 m (1 ft) diameter cypress tree,
and 0.46 m (1.5 ft) north of a steel witness post.  The bench mark is set 0.1 m
(0.3 ft) above grade, crimped to the top of an unspecified steel rod driven an
unknown depth.



                         BENCH MARK STAMPING:  SANDY NO 5 1974
                         DESIGNATION:          866 1703 SANDY NO 5

MONUMENTATION:           Bench Mark disk                       VM#:         3860
AGENCY:                  US Coast & Geodetic Survey
                         (USC&GS)                                 IDB PID#:        
SETTING CLASSIFICATION:  Unspecified steel rod                 OPUS PID:        
LATITUDE:   33° 30.4' N (  33.50670)          LONGITUDE:  79°  8.8' W ( -79.14670)


The bench mark is a disk located 9 m (30 ft) east of the east bank of the creek,
6.71 m (22.0 ft) NNE of bench mark SANDY NO 4 1974, 6.16 m (20.2 ft) south of a
small meander that penetrates Sandy Island from the creek, 1.74 m (5.7 ft) SE of
a 1 m (2 ft) diameter oak tree, and 1.01 m (3.3 ft) NNE of a steel witness post.
 The bench mark is set 0.15 m (0.5 ft) above grade, crimped to the top of an
unspecified steel rod driven an unknown depth.

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

                                                                                
Station ID: 8661703                         PUBLICATION DATE:  06/28/2004
Name:       SANDY ISLAND, THOROUGHFARE CREEK                  
            SC
NOAA Chart: 11535                           Latitude:   33° 30.4' N (  33.50670)
USGS Quad:  PLANTERSVILLE                   Longitude:  79°  8.7' W ( -79.14500)


                            T I D A L   D A T U M S 


Tidal datums at SANDY ISLAND, THOROUGHFARE CREEK based on:

     LENGTH OF SERIES:      7 MONTHS
     TIME PERIOD:           June 1975 - December 1975
     TIDAL EPOCH:           1983-2001
     CONTROL TIDE STATION:  8662746 WINYAH BAY, SOUTH ISLAND PLANTATION


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

     MEAN HIGHER HIGH WATER                     MHHW   =  1.122
     MEAN HIGH WATER                            MHW    =  1.070
     MEAN SEA LEVEL                             MSL    =  0.614
     MEAN TIDE LEVEL                            MTL    =  0.561
     MEAN LOW WATER                             MLW    =  0.052
     MEAN LOWER LOW WATER                       MLLW   =  0.000

North American Vertical Datum (NAVD88)

Bench Mark Elevation Information                In METERS above:

     Stamping or Designation                    MLLW        MHW

     SANDY NO 1 1974                             1.003   -0.067
     SANDY NO 2 1974                             0.945   -0.125
     SANDY NO 3 1974                             1.152    0.082
     SANDY NO 4 1974                             1.120    0.050
     SANDY NO 5 1974                             1.310    0.240


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

                                                                                
Station ID: 8661703                         PUBLICATION DATE:  06/28/2004
Name:       SANDY ISLAND, THOROUGHFARE CREEK                  
            SC
NOAA Chart: 11535                           Latitude:   33° 30.4' N (  33.50670)
USGS Quad:  PLANTERSVILLE                   Longitude:  79°  8.7' W ( -79.14500)


                             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.

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Products available at 8661703 SANDY ISLAND, THOROUGHFARE CREEK, SC

Revised: 08/08/2018
NOAA / National Ocean Service
Web site owner: Center for Operational Oceanographic Products and Services