U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Datums Page Page 1 of 6
Station ID: 8667172 PUBLICATION DATE: 05/23/2003
Name: SHELDON, HUSPA CREEK
SC
NOAA Chart: 11519 Latitude: 32° 35.0' N ( 32.58330)
USGS Quad: YEMASSEE Longitude: 80° 47.0' W ( -80.78330)
To reach the bench marks from the Post Office in Sheldon, proceed south on
County Road S-7-292 for 0.24 km (0.15 mi), then SE along County Road S-7-59 for
1.8 km (1.1 mi), then proceed 0.3 km (0.2 mi) east on a dirt road (crossing
railroad tracks) to a fork, then take the right fork and proceed east for 0.5 km
(0.3 mi) to the end of the road and a one-story frame house. The bench marks
are along the road leading to the house. The tide gauge and staff were located
on an NOS constructed platform at the end of a floating dock.
T I D A L B E N C H M A R K S
PRIMARY BENCH MARK STAMPING: 7172 A 1979
DESIGNATION: 866 7172 A TIDAL
MONUMENTATION: Tidal Station disk VM#: 6731
AGENCY: National Ocean Survey (NOS) IDB PID#: CK2189
SETTING CLASSIFICATION: Stainless steel rod OPUS PID:
LATITUDE: 32° 35.0' N ( 32.58330) LONGITUDE: 80° 47.0' W ( -80.78330)
The primary bench mark is a disk located near the pier, 24.38 m (80.0 ft) ENE of
a twin- trunk live oak tree, 4.57 m (15.0 ft) south of a cedar tree, 4.27 m
(14.0 ft) NW of the creek bank, and 0.88 m (2.9 ft) NW of the NE corner of a
storage shed along the creek bank. The bench mark is crimped to the top of a
stainless steel rod driven 5.5 m (18 ft) to refusal, and encased in a PVC pipe
and concrete kickblock.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 2 of 6
Station ID: 8667172 PUBLICATION DATE: 05/23/2003
Name: SHELDON, HUSPA CREEK
SC
NOAA Chart: 11519 Latitude: 32° 35.0' N ( 32.58330)
USGS Quad: YEMASSEE Longitude: 80° 47.0' W ( -80.78330)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 7172 C 1979
DESIGNATION: 866 7172 C TIDAL
MONUMENTATION: Tidal Station disk VM#: 6733
AGENCY: National Ocean Survey (NOS) IDB PID#: CK2190
SETTING CLASSIFICATION: Stainless steel rod OPUS PID:
LATITUDE: 32° 35.0' N ( 32.58330) LONGITUDE: 80° 47.0' W ( -80.78330)
The primary bench mark is a disk located 15.39 m (50.5 ft) SE of the SE corner
of an old concrete foundation, 15.18 m (49.8 ft) SW of the SW corner of a small
workshop, 10.97 m (36.0 ft) north of the centerline of a dirt driveway, 0.61 m
(2.0 ft) NW of utility pole #258078, and 0.37 m (1.2 ft) SW of a round concrete
pipe flower planter. The bench mark is set level with the ground, crimped to
the top of a stainless steel rod driven 9.1 m (30 ft) to refusal, and encased in
a PVC pipe and concrete kickblock.
BENCH MARK STAMPING: 7172 E 1979
DESIGNATION: 866 7172 E TIDAL
MONUMENTATION: Tidal Station disk VM#: 6735
AGENCY: National Ocean Survey (NOS) IDB PID#: CK2188
SETTING CLASSIFICATION: Stainless steel rod OPUS PID:
LATITUDE: 32° 35.0' N ( 32.58330) LONGITUDE: 80° 47.1' W ( -80.78500)
The bench mark is a disk located along the dirt road leading to the house, 12.47
m (40.9 ft) SE of the SE corner of a concrete block house, 4.24 m (13.9 ft)
north of the centerline of the gravel drive, 1.16 m (3.8 ft) SW of an unmarked
utility pole, and 0.98 m (3.2 ft) south of a barbed wire fence. The bench mark
is set level with the ground, crimped to the top of a stainless steel rod driven
7.30 m (22.3 ft) to refusal, and encased in a PVC pipe and concrete kickblock.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 3 of 6
Station ID: 8667172 PUBLICATION DATE: 05/23/2003
Name: SHELDON, HUSPA CREEK
SC
NOAA Chart: 11519 Latitude: 32° 35.0' N ( 32.58330)
USGS Quad: YEMASSEE Longitude: 80° 47.0' W ( -80.78330)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 7172 F 1982
DESIGNATION: 866 7172 F TIDAL
MONUMENTATION: Tidal Station disk VM#: 12481
AGENCY: National Ocean Survey (NOS) IDB PID#:
SETTING CLASSIFICATION: Concrete monument OPUS PID:
LATITUDE: 32° 35.0' N ( 32.58330) LONGITUDE: 80° 47.0' W ( -80.78330)
The bench mark is a disk set in the top of a concrete monument, 42.06 m (138.0
ft) NE of bench mark 7172 C 1979, 28.35 m (93.0 ft) ESE of the south corner of a
white shed, 15.54 m (51.0 ft) NE of the east corner of a brown wooden house,
4.66 m (15.3 ft) SW of a guy wire anchor, and 0.61 m (2.0 ft) NE of utility pole
#RP-134-64-5.
BENCH MARK STAMPING: 7172 G 1982
DESIGNATION: 866 7172 G TIDAL
MONUMENTATION: Tidal Station disk VM#: 12482
AGENCY: National Ocean Survey (NOS) IDB PID#: CK2191
SETTING CLASSIFICATION: Concrete monument OPUS PID:
LATITUDE: 32° 35.0' N ( 32.58330) LONGITUDE: 80° 47.1' W ( -80.78500)
The bench mark is a disk set in the top of a concrete monument on the south side
of the dirt road leading to the creek, 103.3 m (339.0 ft) SE of bench mark 7172
E 1979, 25.30 m (83.0 ft) SW of the center of concrete steps leading to a
trailer, 1.98 m (6.5 ft) south of the centerline of a dirt road, and 1.37 m (4.5
ft) WNW of a 1.2 m (4 ft) tall corner creosote post with a sign.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 4 of 6
Station ID: 8667172 PUBLICATION DATE: 05/23/2003
Name: SHELDON, HUSPA CREEK
SC
NOAA Chart: 11519 Latitude: 32° 35.0' N ( 32.58330)
USGS Quad: YEMASSEE Longitude: 80° 47.0' W ( -80.78330)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 7172 H 1982
DESIGNATION: 866 7172 H TIDAL
MONUMENTATION: Tidal Station disk VM#: 12483
AGENCY: National Ocean Survey (NOS) IDB PID#:
SETTING CLASSIFICATION: Stainless steel rod OPUS PID:
LATITUDE: 32° 35.0' N ( 32.58330) LONGITUDE: 80° 47.0' W ( -80.78330)
The bench mark is a disk located 7.53 m (24.7 ft) NNE of the centerline of the
dirt road leading to the house, 7.76 m (25.2 ft) SSW of a 0.76 m (2.5 ft)
diameter pine tree, 5.67 m (18.6 ft) SW of a 1.5-foot diameter gum tree, and
0.61 m (2.0 ft) NE of power pole #239989. The bench mark is set level with the
ground, crimped to the top of a stainless steel rod driven 7.3 m (24 ft) to
refusal, and encased in a PVC pipe and concrete kickblock.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 5 of 6
Station ID: 8667172 PUBLICATION DATE: 05/23/2003
Name: SHELDON, HUSPA CREEK
SC
NOAA Chart: 11519 Latitude: 32° 35.0' N ( 32.58330)
USGS Quad: YEMASSEE Longitude: 80° 47.0' W ( -80.78330)
T I D A L D A T U M S
Tidal datums at SHELDON, HUSPA CREEK based on:
LENGTH OF SERIES: 1 Year
TIME PERIOD: July 1979 - June 1980
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:
MEAN HIGHER HIGH WATER MHHW = 2.637
MEAN HIGH WATER MHW = 2.512
MEAN SEA LEVEL MSL = 1.474
North American Vertical Datum NAVD88 = 1.423
MEAN TIDE LEVEL MTL = 1.282
MEAN LOW WATER MLW = 0.053
MEAN LOWER LOW WATER MLLW = 0.000
North American Vertical Datum (NAVD88)
Bench Mark Elevation Information In METERS above:
Stamping or Designation MLLW MHW
7172 A 1979 3.358 0.846
7172 C 1979 6.714 4.202
7172 E 1979 9.040 6.528
7172 F 1982 6.769 4.257
7172 G 1982 7.443 4.931
7172 H 1982 7.326 4.814
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 6 of 6
Station ID: 8667172 PUBLICATION DATE: 05/23/2003
Name: SHELDON, HUSPA CREEK
SC
NOAA Chart: 11519 Latitude: 32° 35.0' N ( 32.58330)
USGS Quad: YEMASSEE Longitude: 80° 47.0' W ( -80.78330)
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.