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National Ocean Service
Datums Page Page 1 of 5
Station ID: 8666749 PUBLICATION DATE: 02/05/2004
Name: AIRY HALL, ASHEPOO RIVER
SC
NOAA Chart: 11517 Latitude: 32° 37.9' N ( 32.63170)
USGS Quad: FENWICK Longitude: 80° 28.3' W ( -80.47170)
To reach the tidal bench marks from the intersection of U.S. Highway 17 and
County Road S-15-26, proceed south on County Road S-15-26 for 14.6 km (9.1 mi)
to the entrance to Airy Hall Plantation, turn left (NE) onto the sand road and
go 6.3 km (3.9 mi) to the main plantation house. The bench marks are south of
the house between the stables and the dock. The tide gauge and staff were on a
dock 91 m (300 ft) SE of the house at the end of a row of Azaleas lining the
lawn.
T I D A L B E N C H M A R K S
PRIMARY BENCH MARK STAMPING: 6749 A 1981
DESIGNATION: 866 6749 A TIDAL
MONUMENTATION: Tidal Station disk VM#: 4342
AGENCY: National Ocean Survey (NOS) IDB PID#: CK3027
SETTING CLASSIFICATION: Stainless steel rod OPUS PID:
LATITUDE: 32° 37.9' N ( 32.63170) LONGITUDE: 80° 28.4' W ( -80.47330)
The primary bench mark is a disk located near the entrance to the boat dock on
the east side of the house, 8.23 m (27.0 ft) south of the centerline of the walk
ramp to the dock, 3.66 m (12.0 ft) WSW of the edge of the river bank, 2.10 m
(6.9 ft) west of a 0.52 m (1.7 ft) diameter oak tree, 1.83 m (6.0 ft) SSW of a
0.46 m (1.5 ft) diameter pine tree, and 3.66 m (12.0 ft) WSW of the edge of the
river bank. The bench mark is set level with the ground, crimped to the top of
a stainless steel rod driven 13.4 m (44 ft) to refusal, and encased in a 5-inch
PVC pipe and 0.40 m (1.3 ft) diameter concrete kickblock.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 2 of 5
Station ID: 8666749 PUBLICATION DATE: 02/05/2004
Name: AIRY HALL, ASHEPOO RIVER
SC
NOAA Chart: 11517 Latitude: 32° 37.9' N ( 32.63170)
USGS Quad: FENWICK Longitude: 80° 28.3' W ( -80.47170)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 6749 C 1981
DESIGNATION: 866 6749 C TIDAL
MONUMENTATION: Tidal Station disk VM#: 4343
AGENCY: National Ocean Survey (NOS) IDB PID#: CK3025
SETTING CLASSIFICATION: Stainless steel rod OPUS PID:
LATITUDE: 32° 37.9' N ( 32.63170) LONGITUDE: 80° 28.4' W ( -80.47330)
The bench mark is a disk located in the SE angle of the road leading to the dock
and the road into the woods, 10.82 m (35.5 ft) ENE of the centerline of the road
leading into the woods, 8.53 m (28.0 ft) WNW of an 2 m (8 ft) diameter Y-shaped
oak tree, and 5.18 m (17.0 ft) SSE of the centerline of the road leading to the
dock. The bench mark is set at ground level, crimped to the top of a stainless
steel rod driven 13.7 m (45 ft) to refusal, and encased in a 5-inch PVC pipe and
0.30 m (1.0 ft) diameter concrete kickblock.
BENCH MARK STAMPING: 6749 F 1981
DESIGNATION: 866 6749 F TIDAL
MONUMENTATION: Tidal Station disk VM#: 4344
AGENCY: National Ocean Survey (NOS) IDB PID#: CK3026
SETTING CLASSIFICATION: Concrete monument OPUS PID:
LATITUDE: 32° 37.9' N ( 32.63170) LONGITUDE: 80° 28.4' W ( -80.47330)
The bench mark is a disk set in the top of a concrete monument located between
the old road leading to the dock and the house, 59.74 m (196.0 ft) SE of the SE
corner of the house, 4.57 m (15.0 ft) NNW of the centerline of the road leading
to the dock, 2.44 m (8.0 ft) south of a double trunk China-berry tree, and 0.12
m (0.4 ft) above ground level.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 3 of 5
Station ID: 8666749 PUBLICATION DATE: 02/05/2004
Name: AIRY HALL, ASHEPOO RIVER
SC
NOAA Chart: 11517 Latitude: 32° 37.9' N ( 32.63170)
USGS Quad: FENWICK Longitude: 80° 28.3' W ( -80.47170)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 6749 G 1981
DESIGNATION: 866 6749 G TIDAL
MONUMENTATION: Tidal Station disk VM#: 4345
AGENCY: National Ocean Survey (NOS) IDB PID#: CK3024
SETTING CLASSIFICATION: Concrete monument OPUS PID:
LATITUDE: 32° 37.9' N ( 32.63170) LONGITUDE: 80° 28.4' W ( -80.47330)
The bench mark is a disk set in the top of a concrete monument between a dirt
road leading west and a hedge row, 7.62 m (25.0 ft) NNW of the centerline of the
dirt road, 2.01 m (6.6 ft) SSE of the hedgeline, and 0.12 m (0.4 ft) above
ground level.
BENCH MARK STAMPING: 6749 H 1981
DESIGNATION: 866 6749 H TIDAL
MONUMENTATION: Tidal Station disk VM#: 4346
AGENCY: National Ocean Survey (NOS) IDB PID#: CK3023
SETTING CLASSIFICATION: Concrete monument OPUS PID:
LATITUDE: 32° 37.9' N ( 32.63170) LONGITUDE: 80° 28.4' W ( -80.47330)
The bench mark is a disk set in the top of a concrete monument located near a
triple trunk oak tree, 12.68 m (41.6 ft) SE of the triple trunk oak tree, 9 m
(30 ft) NNW of the centerline of the dirt road leading to the dock, 3.66 m (12.0
ft) west of 0.46 m (1.5 ft) diameter water oak tree, and 0.15 m (0.5 ft) above
ground level.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 4 of 5
Station ID: 8666749 PUBLICATION DATE: 02/05/2004
Name: AIRY HALL, ASHEPOO RIVER
SC
NOAA Chart: 11517 Latitude: 32° 37.9' N ( 32.63170)
USGS Quad: FENWICK Longitude: 80° 28.3' W ( -80.47170)
T I D A L D A T U M S
Tidal datums at AIRY HALL, ASHEPOO RIVER based on:
LENGTH OF SERIES: 6 MONTHS
TIME PERIOD: May 1981 - October 1981
TIDAL EPOCH: 1983-2001
CONTROL TIDE STATION: 8664022 GEN. DYNAMICS PIER, COOPER R.
Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in METERS:
MEAN HIGHER HIGH WATER MHHW = 1.350
MEAN HIGH WATER MHW = 1.300
MEAN SEA LEVEL MSL = 0.769
MEAN TIDE LEVEL MTL = 0.683
North American Vertical Datum NAVD88 = 0.671
MEAN LOW WATER MLW = 0.067
MEAN LOWER LOW WATER MLLW = 0.000
North American Vertical Datum (NAVD88)
Bench Mark Elevation Information In METERS above:
Stamping or Designation MLLW MHW
6749 A 1981 3.800 2.500
6749 C 1981 4.075 2.775
6749 F 1981 3.797 2.497
6749 G 1981 4.637 3.337
6749 H 1981 5.256 3.956
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 5 of 5
Station ID: 8666749 PUBLICATION DATE: 02/05/2004
Name: AIRY HALL, ASHEPOO RIVER
SC
NOAA Chart: 11517 Latitude: 32° 37.9' N ( 32.63170)
USGS Quad: FENWICK Longitude: 80° 28.3' W ( -80.47170)
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.