U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Datums Page Page 1 of 5
PUBLICATION DATE: 07/06/1987
Station ID: 8667999 SUPERCEDED DATE: 04/21/2003
Name: BEAUFORT, BEAUFORT RIVER
SOUTH CAROLINA
NOAA Chart: 11519 Latitude: 32° 25.8' N
USGS Quad: BEAUFORT Longitude: 80° 40.2' W
To reach the tidal bench marks from the junction of U.S. Highway 17S and 21S,
proceed south on U.S. Highway 21S for 16.0 miles (25.7 km) to Carteret Street in
downtown Beaufort, turn right and continue on Carteret Street for 0.6 mile (1.0
km) to Bay Street, turn right on Bay Street for 0.3 mile (0.5 km) to City Park
and Marina. The bench marks are located in downtown Beaufort and along the
waterfront. The gage and staff were located on the seawall near the ramp to the
floating docks.
T I D A L B E N C H M A R K S
PRIMARY BENCH MARK STAMPING: 7999 G 1980
MONUMENTATION: Survey Disk VM#: 4433
AGENCY: PID#: CK2243
SETTING CLASSIFICATION: Copper Clad Steel Rod
The bench mark is located in City Park between the Pavilion and the covered
walkway, 85.0 feet (25.9 m) NE of the angle in the seawall, 83.3 feet (25.4 m)
NW of the most NW corner of the Pavilion, 26.3 feet (8.0 m) SE of the covered
walkway, and 7.4 feet (2.3 m) SW of the Thomas Heyward, Jr. memorial plaque.
The bench mark is 0.3 foot (0.1 m) below ground level, crimped to a copper-clad
steel rod driven 30 feet (9 m) to refusal, and encased in 4 inch PVC pipe and
concrete kickblock.
BENCH MARK STAMPING: NO 4 1933
MONUMENTATION: Survey Disk VM#: 4430
AGENCY: PID#: CK0882
SETTING CLASSIFICATION: Concrete & Shell Composite Seawall
The bench mark is set flush in the top of the concrete and shell composite
seawall on the east side of Wood Memorial Bridge, 117.0 feet (35.7 m) north of
the NE end of the bridge, 86.0 feet (26.2 m) south of the centerline of Bay
Street, 52.9 feet (16.1 m) SSW of a brick monument (WWII), and 42.3 feet (12.9
m) east of the centerline of Carteret Street.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 2 of 5
PUBLICATION DATE: 07/06/1987
Station ID: 8667999 SUPERCEDED DATE: 04/21/2003
Name: BEAUFORT, BEAUFORT RIVER
SOUTH CAROLINA
NOAA Chart: 11519 Latitude: 32° 25.8' N
USGS Quad: BEAUFORT Longitude: 80° 40.2' W
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: NO 7 1973
MONUMENTATION: Survey Disk VM#: 4431
AGENCY: PID#: CK2244
SETTING CLASSIFICATION: Concrete & Shell Seawall
The bench mark is set flush in the top of the concrete and shell composite
seawall on the east side of Wood Memorial Bridge, 158.0 feet (48.2 m) east of
the centerline of Carteret Street, 114.3 feet (34.8 m) ENE of Bench Mark NO 4
1933, 58.0 feet (17.7 m) south of the centerline of Bay Street, and 31.4 feet
(9.6 m) SW of the most easterly of two cannons.
BENCH MARK STAMPING: NO 8 1973
MONUMENTATION: Survey Disk VM#: 4432
AGENCY: PID#: CK2245
SETTING CLASSIFICATION: Concrete & Shell Seawall
The bench mark is set flush in the top of the concrete and shell composite
seawall on the east side of the Wood Memorial Bridge, 276.6 feet (84.3 m) east
of the centerline of Carteret Street, 131 feet (40 m) east of Bench Mark NO 4
1933, 118.6 feet (36.1 m) ENE of Bench Mark NO 7 1973, 34.9 feet (10.6 m) south
of the centerline of the intersection of Bay and New Streets, and 17.9 feet (5.5
m) west of the white picket fence.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 3 of 5
PUBLICATION DATE: 07/06/1987
Station ID: 8667999 SUPERCEDED DATE: 04/21/2003
Name: BEAUFORT, BEAUFORT RIVER
SOUTH CAROLINA
NOAA Chart: 11519 Latitude: 32° 25.8' N
USGS Quad: BEAUFORT Longitude: 80° 40.2' W
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 2
MONUMENTATION: Survey Disk VM#: 4434
AGENCY: PID#: CK0887
SETTING CLASSIFICATION: Brick Sill
The bench mark is set in the top of a brick sill on the east face of the City
Hall Administration Offices building (Old Post Office) on the west side of
Carteret Street, 40.6 feet (12.4 m) WSW of the centerline of Carteret Street,
10.0 feet (3.0 m) NNW of the bottom step at the east entrance of the building,
and 3.0 (0.9 m) SW of the most southerly wooden sign post for City Hall
Administration Offices, and 1.8 feet (0.5 m) above the concrete landing.
BENCH MARK STAMPING: NO 6
MONUMENTATION: Survey Disk VM#: 4435
AGENCY: PID#: CK0886
SETTING CLASSIFICATION: Concrete Footing
The bench mark is set flush in the concrete footing at the NE corner of Beaufort
County Library on the corner of Carteret and Craven Streets, 62.7 feet (19.1 m)
west of the centerline of Carteret Street, 29.1 feet (8.9 m) south of the
centerline of Craven Street 24.0 feet (7.3 m) SSW of a fire hydrant, 3.8 feet
(1.2 m) west of the NE corner of the Library, and level with the sidewalk.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 4 of 5
PUBLICATION DATE: 07/06/1987
Station ID: 8667999 SUPERCEDED DATE: 04/21/2003
Name: BEAUFORT, BEAUFORT RIVER
SOUTH CAROLINA
NOAA Chart: 11519 Latitude: 32° 25.8' N
USGS Quad: BEAUFORT Longitude: 80° 40.2' W
T I D A L D A T U M S
Tidal datums at BEAUFORT, BEAUFORT RIVER based on:
LENGTH OF SERIES: 7 YEARS
TIME PERIOD: 1978-1984
TIDAL EPOCH: 1960-1978
CONTROL TIDE STATION: 8665530 CHARLESTON
Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in FEET:
HIGHEST OBSERVED WATER LEVEL (09/04/1979) = 11.72
MEAN HIGHER HIGH WATER MHHW = 8.03
MEAN HIGH WATER MHW = 7.67
MEAN TIDE LEVEL MTL = 3.94
* NATIONAL GEODETIC VERTICAL DATUM NGVD29 = 3.93
MEAN LOW WATER MLW = 0.22
MEAN LOWER LOW WATER MLLW = 0.00
LOWEST OBSERVED WATER LEVEL (12/24/1983) = -2.09
* NGVD reference based on elevations published in Quad 320803, 1964, and NOS
leveling of 1985.
North American Vertical Datum (NAVD88)
Bench Mark Elevation Information In FEET above:
Stamping or Designation MLLW MHW
7999 G 1980 11.19 3.52
NO 4 1933 14.32 6.65
NO 7 1973 13.96 6.29
NO 8 1973 13.77 6.10
2 14.76 7.09
NO 6 13.54 5.87
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 5 of 5
PUBLICATION DATE: 07/06/1987
Station ID: 8667999 SUPERCEDED DATE: 04/21/2003
Name: BEAUFORT, BEAUFORT RIVER
SOUTH CAROLINA
NOAA Chart: 11519 Latitude: 32° 25.8' N
USGS Quad: BEAUFORT Longitude: 80° 40.2' W
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 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.