U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Datums Page Page 1 of 6
Station ID: 8667411 PUBLICATION DATE: 02/05/2004
Name: LOBECO, WHALE BRANCH, COOSAW RIVER
SC
NOAA Chart: 11519 Latitude: 32° 34.4' N ( 32.57330)
USGS Quad: BENNETTS POINT Longitude: 80° 44.7' W ( -80.74500)
To reach the tidal bench marks from the intersection of U.S. Highway 21 and
State Highway 116 at the Marine Corps Air Station entrance, proceed north on
U.S. Highway 21 for 9.7 km (6.0 mi) to the J. V. Dunbar Sr. Memorial Bridge over
Whale Branch. The bench marks are located in the median of U.S. Highway 21
leading south toward Beaufort. The tide gage and staff were located on the
fender pilings on the east side of the bridge.
T I D A L B E N C H M A R K S
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 2 of 6
Station ID: 8667411 PUBLICATION DATE: 02/05/2004
Name: LOBECO, WHALE BRANCH, COOSAW RIVER
SC
NOAA Chart: 11519 Latitude: 32° 34.4' N ( 32.57330)
USGS Quad: BENNETTS POINT Longitude: 80° 44.7' W ( -80.74500)
T I D A L B E N C H M A R K S
PRIMARY BENCH MARK STAMPING: J 107 1962
DESIGNATION: J 107
MONUMENTATION: Bench Mark disk VM#: 6761
AGENCY: US Coast and Geodetic Survey
(USC&GS) IDB PID#: CK1429
SETTING CLASSIFICATION: Bridge abutment OPUS PID:
LATITUDE: 32° 32.4' N ( 32.54000) LONGITUDE: 80° 44.7' W ( -80.74500)
The primary bench mark is a disk set flush in the SW abutment of the J. V.
Dunbar Sr. Memorial Bridge, 6.95 m (22.8 ft) west of the SE corner of the
bridge, 4.88 m (16.0 ft) NE of utility pole #144553, and 3.81 m (12.5 ft) west
of the centerline of the northbound lane.
BENCH MARK STAMPING: 7411 B 1977
DESIGNATION: 866 7411 B TIDAL
MONUMENTATION: Tidal Station disk VM#: 6762
AGENCY: National Ocean Survey (NOS) IDB PID#: CK2200
SETTING CLASSIFICATION: Galvanized steel rod OPUS PID:
LATITUDE: 32° 32.3' N ( 32.53830) LONGITUDE: 80° 44.7' W ( -80.74500)
The bench mark is a disk located south of the bridge, between the northbound and
southbound lanes of U.S. Route 21, 112.78 m (370.0 ft) SSW of bench mark J 107
1962, 108.81 m (357.0 ft) north of bench mark 7411 C 1977, 6.71 m (22.0 ft) WNW
of the centerline of the northbound lane, and 0.64 m (2.1 ft) east of a witness
post. The bench mark is set at ground level, crimped to the top of a steel rod
driven 11.6 m (38 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 3 of 6
Station ID: 8667411 PUBLICATION DATE: 02/05/2004
Name: LOBECO, WHALE BRANCH, COOSAW RIVER
SC
NOAA Chart: 11519 Latitude: 32° 34.4' N ( 32.57330)
USGS Quad: BENNETTS POINT Longitude: 80° 44.7' W ( -80.74500)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 7411 C 1977
DESIGNATION: 866 7411 C TIDAL
MONUMENTATION: Tidal Station disk VM#: 6763
AGENCY: National Ocean Survey (NOS) IDB PID#: CK2201
SETTING CLASSIFICATION: Galvanized steel rod OPUS PID:
LATITUDE: 32° 32.3' N ( 32.53830) LONGITUDE: 80° 44.7' W ( -80.74500)
The bench mark is a disk located south of the bridge along the west side of the
northbound lane of U.S. Route 21, 109 m (358 ft) north of bench mark 7411 F
1982, 108.81 m (357.0 ft) south of bench mark 7411 B 1977, 6.40 m (21.0 ft) west
of the centerline of the northbound lane, and 0.49 m (1.6 ft) east of a witness
post. The bench mark is set at ground level, crimped to a steel rod driven 9.1
m (30 ft) to refusal, and encased in a 4-inch PVC pipe and concrete kickblock.
BENCH MARK STAMPING: 7411 F 1982
DESIGNATION: 866 7411 F TIDAL
MONUMENTATION: Tidal Station disk VM#: 6765
AGENCY: National Ocean Survey (NOS) IDB PID#: CK2202
SETTING CLASSIFICATION: Concrete monument OPUS PID:
LATITUDE: 32° 32.3' N ( 32.53830) LONGITUDE: 80° 44.7' W ( -80.74500)
The bench mark is a disk set in a concrete monument which is 1 m (3 ft) deep and
0.3 m (1 ft) in diameter, 109 m (358 ft) south of bench mark 7411 C 1977, 22.10
m (72.5 ft) east of the centerline of the southbound lane, 8 m (26 ft) west of
the centerline of the northbound lane, 0.73 m (2.4 ft) west of a witness post,
and at ground level.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 4 of 6
Station ID: 8667411 PUBLICATION DATE: 02/05/2004
Name: LOBECO, WHALE BRANCH, COOSAW RIVER
SC
NOAA Chart: 11519 Latitude: 32° 34.4' N ( 32.57330)
USGS Quad: BENNETTS POINT Longitude: 80° 44.7' W ( -80.74500)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 7411 G 1982
DESIGNATION: 866 7411 G TIDAL
MONUMENTATION: Survey disk VM#: 6771
AGENCY: National Ocean Survey (NOS) IDB PID#: CK4352
SETTING CLASSIFICATION: Stainless steel rod OPUS PID#: CK4352
LATITUDE: 32° 32.1' N ( 32.53500) LONGITUDE: 80° 44.8' W ( -80.74670)
The bench mark is a disk located south of the bridge, along a service road
conecting the northbound and southbound lanes of U.S. Route 21, 90.25 m (296.1
ft) SSW of bench mark 7411 F 1982, 16.15 m (53.0 ft) north of the turnaround
lane between the northbound and southbound lanes, 14.78 m (48.5 ft) ESE of the
centerline of the southbound lane, 7.71 m (25.3 ft) WNW of the centerline of the
northbound lane, and 0.46 m (1.5 ft) SSW of a witness post. The bench mark is
set 3 cm (0.1 ft) below ground level, crimped to the top of a stainless steel
rod driven 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: 8667411 PUBLICATION DATE: 02/05/2004
Name: LOBECO, WHALE BRANCH, COOSAW RIVER
SC
NOAA Chart: 11519 Latitude: 32° 34.4' N ( 32.57330)
USGS Quad: BENNETTS POINT Longitude: 80° 44.7' W ( -80.74500)
T I D A L D A T U M S
Tidal datums at LOBECO, WHALE BRANCH, COOSAW RIVER based on:
LENGTH OF SERIES: 1 YEAR
TIME PERIOD: March 1978 - February 1979
TIDAL EPOCH: 1983-2001
CONTROL TIDE STATION: 8667999 BEAUFORT
Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in METERS:
HIGHEST OBSERVED WATER LEVEL (07/19/1978) = 3.083
MEAN HIGHER HIGH WATER MHHW = 2.542
MEAN HIGH WATER MHW = 2.424
MEAN SEA LEVEL MSL = 1.415
North American Vertical Datum NAVD88 = 1.414
MEAN TIDE LEVEL MTL = 1.244
MEAN LOW WATER MLW = 0.063
MEAN LOWER LOW WATER MLLW = 0.000
LOWEST OBSERVED WATER LEVEL (01/25/1979) = -0.980
North American Vertical Datum (NAVD88)
Bench Mark Elevation Information In METERS above:
Stamping or Designation MLLW MHW
J 107 1962 4.827 2.403
7411 B 1977 3.188 0.764
7411 C 1977 3.398 0.974
7411 F 1982 3.342 0.918
7411 G 1982 3.580 1.156
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 6 of 6
Station ID: 8667411 PUBLICATION DATE: 02/05/2004
Name: LOBECO, WHALE BRANCH, COOSAW RIVER
SC
NOAA Chart: 11519 Latitude: 32° 34.4' N ( 32.57330)
USGS Quad: BENNETTS POINT Longitude: 80° 44.7' W ( -80.74500)
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.