U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Datums Page Page 1 of 5
Station ID: 8665637 PUBLICATION DATE: 07/14/2003
Name: THE COVE, CHARLESTON HARBOR
SC
NOAA Chart: 11523 Latitude: 32° 45.8' N ( 32.76330)
USGS Quad: FORT MOULTRIE Longitude: 79° 51.4' W ( -79.85670)
To reach the tidal bench marks from the east end of Ben Sawyer Bridge in
Sullivans Island, proceed east on State Highway 703 for 1.1 km (0.7 mi) to
County Road S-10-599, turn right onto County Road S-10-599 and go 2.1 km (1.3
mi) to Fort Moultrie Visitors Center. The bench marks are near the parking area
and the shore. The tide gage and staff were located on the visitors pier.
T I D A L B E N C H M A R K S
PRIMARY BENCH MARK STAMPING: 5637 C 1977
DESIGNATION: 866 5637 C TIDAL
MONUMENTATION: Tidal Station disk VM#: 4212
AGENCY: National Ocean Survey (NOS) IDB PID#: CJ0598
SETTING CLASSIFICATION: Galvanized steel rod OPUS PID#: CJ0598
LATITUDE: 32° 45.7' N ( 32.76170) LONGITUDE: 79° 51.4' W ( -79.85670)
The primary bench mark is a disk located at the north end of an I-shaped median
in the visitors parking area, 49.53 m (162.4 ft) west of bench mark 5637 F 1982,
10.94 m (35.9 ft) east of the east corner of a metal storm grate set into the
asphalt, 5.00 m (16.4 ft) NNE of a 0.30 (1.0 ft) crepe myrtle tree, 0.64 m (2.1
ft) east of the NE corner of the concrete base of a metal security light post,
and 0.49 m (1.6 ft) west of the west edge of a concrete sidewalk on the east
side of the median. The bench mark is set level with the ground, crimped to the
top of a galvanized steel rod driven 4.9 m (16 ft) to refusal, and encased in a
4-inch PVC pipe and concrete kickblock.
BENCH MARK STAMPING: FMNM AP 1 TRACT 2 1971
DESIGNATION: AP 1
MONUMENTATION: Survey disk VM#: 4210
AGENCY: US Department of Interior (USDI) IDB PID#: CJ0600
SETTING CLASSIFICATION: Shallow-set pipe OPUS PID:
LATITUDE: 32° 45.7' N ( 32.76170) LONGITUDE: 79° 51.4' W ( -79.85670)
The bench mark is a disk brazed to a 1 m (3 ft) long, 2.5-inch pipe, located on
the NE boundary line of the visitors center, 50 m (164 ft) ESE of the centerline
of the concrete walkway leading to the visitors pier, 41.97 m (137.7 ft) north
of the NW corner of a small brick telephone substation building, 8.96 m (29.4
ft) WNW of the approximate center of a private wooden dock, and 1.83 m (6.0 ft)
NNE of a 0.3 m (1.0 ft) diameter pine tree. The bench mark is set level with
the ground, brazed to a 1 m (3 ft) long 2.5-inch pipe, and encased in another
pipe.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 2 of 5
Station ID: 8665637 PUBLICATION DATE: 07/14/2003
Name: THE COVE, CHARLESTON HARBOR
SC
NOAA Chart: 11523 Latitude: 32° 45.8' N ( 32.76330)
USGS Quad: FORT MOULTRIE Longitude: 79° 51.4' W ( -79.85670)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: FMNM AP 4 TRACT 2 1971
DESIGNATION: AP 4
MONUMENTATION: Survey disk VM#: 4211
AGENCY: US Department of Interior (USDI) IDB PID#: CJ0601
SETTING CLASSIFICATION: Shallow-set pipe OPUS PID:
LATITUDE: 32° 45.8' N ( 32.76330) LONGITUDE: 79° 51.4' W ( -79.85670)
The bench mark is a disk brazed to a 1 m (3 ft) long 2.5-inch pipe, located on
the NE boundary line of the visitors center, 25.79 m (84.6 ft) WNW of the
centerline of the concrete walkway leading to the visitors pier, 24.02 m (78.8
ft) west of the SW corner of the visitors pier, 14.84 m (48.7 ft) NNW of the NW
corner of the granite tombstone of Major General William Moultrie, 3.84 m (12.6
ft) south of the NW corner of a rock sea wall, and 1 m (2 ft) east of the west
edge of the marsh. The bench mark is set level with the ground, brazed to a 1 m
(3 ft) long 2.5-inch pipe, and encased in another pipe.
BENCH MARK STAMPING: 5637 E 1977
DESIGNATION: 866 5637 E TIDAL
MONUMENTATION: Tidal Station disk VM#: 4213
AGENCY: National Ocean Survey (NOS) IDB PID#:
SETTING CLASSIFICATION: Galvanized steel rod OPUS PID:
LATITUDE: 32° 45.8' N ( 32.76330) LONGITUDE: 79° 51.4' W ( -79.85670)
The bench mark is a disk located 29 m (95 ft) west of the exit lane of the
visitors parking area, 6.83 m (22.4 ft) WNW of the edge of the sidewalk, 3.72 m
(12.2 ft) south of a 1 m (3 ft) high concrete post, 3.66 m (12.0 ft) east of a
0.61 m (2.0 ft) diameter palmetto tree, and 2.38 m (7.8 ft) east of a chain link
fence on the west side of the park. The bench mark is set 6 cm (0.2 ft) above
the ground, crimped to the top of a galvanized steel rod driven 4.9 m (16 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 5
Station ID: 8665637 PUBLICATION DATE: 07/14/2003
Name: THE COVE, CHARLESTON HARBOR
SC
NOAA Chart: 11523 Latitude: 32° 45.8' N ( 32.76330)
USGS Quad: FORT MOULTRIE Longitude: 79° 51.4' W ( -79.85670)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 5637 F 1982
DESIGNATION: 866 5637 F TIDAL
MONUMENTATION: Tidal Station disk VM#: 4214
AGENCY: National Ocean Survey (NOS) IDB PID#: CJ0599
SETTING CLASSIFICATION: Stainless steel rod OPUS PID:
LATITUDE: 32° 45.7' N ( 32.76170) LONGITUDE: 79° 51.4' W ( -79.85670)
The bench mark is a disk located at a chain link fence corner near an extension
road leading east from the parking area, 24.38 m (80.0 ft) NE of the NE corner
of the parking area, 8.72 m (28.6 ft) WNW of the NW corner of the two-story
brick house at 1219 Cove Avenue, 5.94 m (19.5 ft) SSW of the centerline of the
extension road, and 2.29 m (7.5 ft) WSW of the NW corner of a chain link fence
around the two-story brick house. The bench mark is set level with the ground,
crimped to the top of a stainless steel rod driven 11.0 m (36 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: 8665637 PUBLICATION DATE: 07/14/2003
Name: THE COVE, CHARLESTON HARBOR
SC
NOAA Chart: 11523 Latitude: 32° 45.8' N ( 32.76330)
USGS Quad: FORT MOULTRIE Longitude: 79° 51.4' W ( -79.85670)
T I D A L D A T U M S
Tidal datums at THE COVE, CHARLESTON HARBOR based on:
LENGTH OF SERIES: 4 MONTHS
TIME PERIOD: April 1977 - July 1977
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 = 1.714
MEAN HIGH WATER MHW = 1.603
North American Vertical Datum NAVD88 = 0.950
MEAN SEA LEVEL MSL = 0.856
MEAN TIDE LEVEL MTL = 0.829
MEAN LOW WATER MLW = 0.056
MEAN LOWER LOW WATER MLLW = 0.000
North American Vertical Datum (NAVD88)
Bench Mark Elevation Information In METERS above:
Stamping or Designation MLLW MHW
5637 C 1977 2.805 1.202
FMNM AP 1 TRACT 2 1971 3.247 1.644
FMNM AP 4 TRACT 2 1971 2.439 0.836
5637 E 1977 2.784 1.181
5637 F 1982 2.439 0.836
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 5 of 5
Station ID: 8665637 PUBLICATION DATE: 07/14/2003
Name: THE COVE, CHARLESTON HARBOR
SC
NOAA Chart: 11523 Latitude: 32° 45.8' N ( 32.76330)
USGS Quad: FORT MOULTRIE Longitude: 79° 51.4' W ( -79.85670)
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.