U.S. DEPARTMENT OF COMMERCE
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National Ocean Service
Datums Page Page 1 of 7
Station ID: 8651817 PUBLICATION DATE: 12/04/2012
Name: EDENHOUSE POINT
NC
NOAA Chart: 12205 Latitude: 36° 3.3' N ( 36.05503)
USGS Quad: EDENOUSE Longitude: 76° 41.1' W ( -76.68425)
To reach the tidal bench marks from the north end of the US Highway 17 bridge
crossing the Chowan River, proceed NE on Highway 17 for 1.0 km (0.6 mi) to exit
224, exit right and proceed east 0.6 km (0.4 mi) to an intersection with Queen
Street, turn left and proceed NW on Queen Street for 0.5 km (0.3 mi) to Wildlife
Access Road, turn left and proceed SW on Wildlife Access Road for 0.6 km (1.0
mi) to its termination and a parking lot for a public boat launch. The bench
marks are in the vicinity of the parking lot and along Wildlife Access Road.
The tide gauge is located on the dock at the public boat launch at the NW corner
of the parking lot.
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 7
Station ID: 8651817 PUBLICATION DATE: 12/04/2012
Name: EDENHOUSE POINT
NC
NOAA Chart: 12205 Latitude: 36° 3.3' N ( 36.05503)
USGS Quad: EDENOUSE Longitude: 76° 41.1' W ( -76.68425)
T I D A L B E N C H M A R K S
PRIMARY BENCH MARK STAMPING: P 211 1979
DESIGNATION: P 211
MONUMENTATION: Flange-encased Rod VM#: 20456
AGENCY: NGS IDB PID#: FX2425
SETTING CLASSIFICATION: OPUS PID:
LATITUDE: 36° 3.3' N ( 36.05431) LONGITUDE: 76° 41.0' W ( -76.68281)
The primary bench mark is a flange-encased rod set 4-inches below a standard
National Geodetic Survey logo access cover, 21.7 m (71.3 ft) east of centerline
of drive to boating access area, 13 m (42.9 ft) southwest of a power pole with
reference tag, 12.6 m (41.4 ft) north of centerline of highway and .45 m (1.5
ft) north of the North Post For Wildlife sign. The datum point is a steel knob
on top of a rod flange.
BENCH MARK STAMPING: 1817 A 2012
DESIGNATION: 865 1817 A
MONUMENTATION: Survey disk VM#: 20453
AGENCY: NOS IDB PID#:
SETTING CLASSIFICATION: Concrete walk OPUS PID:
LATITUDE: 36° 3.3' N ( 36.05494) LONGITUDE: 76° 41.0' W ( -76.68411)
The bench mark is set in a concrete walk in the center of the boat ramp, 12.38 m
(40.6 ft) north-northwest of a light post, 8.65 m (28.4 ft) west-northwest of
the east end of the concrete walkway and the edge of the asphalt parking lot,
8.45 m (27.7 ft) south of the eastern end of the sheet piling along the north
edge of the boat ramp, 1.63 m (5.3 ft) west-northwest of southern metal post on
the concrete walkway and 0.40 m (1.3 ft) east-southeast of the west end of the
concrete walk and the beginning of the floating dock.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 3 of 7
Station ID: 8651817 PUBLICATION DATE: 12/04/2012
Name: EDENHOUSE POINT
NC
NOAA Chart: 12205 Latitude: 36° 3.3' N ( 36.05503)
USGS Quad: EDENOUSE Longitude: 76° 41.1' W ( -76.68425)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 1817 B 2012
DESIGNATION: 865 1817 B
MONUMENTATION: Survey disk VM#: 20454
AGENCY: NOS IDB PID#:
SETTING CLASSIFICATION: Road embankment OPUS PID:
LATITUDE: 36° 3.2' N ( 36.05386) LONGITUDE: 76° 41.0' W ( -76.68258)
The bench mark is set in a concrete road embankment, 36.92 m (121.1 ft)
southeast of of the centerline of wildlife access road, 19.18 m (62.9 ft)
southeast of the north end of the concrete embankment, 16.20 m (53.1 ft)
southwest of the southeast most piling along the northeast side of the road
under the Highway 17 overpass, 7.30 m (24.0 ft) southwest of the centerline of
the road under the Highway 17 overpass and 1.93 m (6.3 ft) northwest of the
south end of the concrete embankment.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 4 of 7
Station ID: 8651817 PUBLICATION DATE: 12/04/2012
Name: EDENHOUSE POINT
NC
NOAA Chart: 12205 Latitude: 36° 3.3' N ( 36.05503)
USGS Quad: EDENOUSE Longitude: 76° 41.1' W ( -76.68425)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: TOUR 1980
DESIGNATION: TOUR
MONUMENTATION: Survey disk VM#: 20455
AGENCY: North Carolina Geodetic Survey IDB PID#: FX2907
SETTING CLASSIFICATION: OPUS PID:
LATITUDE: 36° 3.5' N ( 36.05781) LONGITUDE: 76° 40.5' W ( -76.67547)
The bench mark is a standard disk set in the top of a .25 m (10 inch) concrete
cylinder, which is .05 m (2 inches) below ground surface, 29.7 m (97.4 feet)
north-northeast of 15-inch pine all with reference tags, 10.2 m (33.5 ft)
north-northwest of the centerline of US 17, 5.9 m (19.5 ft) south-southwest of
fence post,and 4.7 m (15.4 ft) south-southeast of fence post and 4.6 m (15.1 ft)
west of sign post.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 5 of 7
Station ID: 8651817 PUBLICATION DATE: 12/04/2012
Name: EDENHOUSE POINT
NC
NOAA Chart: 12205 Latitude: 36° 3.3' N ( 36.05503)
USGS Quad: EDENOUSE Longitude: 76° 41.1' W ( -76.68425)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: CHO-1 1974
DESIGNATION: CHO 1
MONUMENTATION: Survey disk VM#: 20457
AGENCY: NGS IDB PID#: FX2044
SETTING CLASSIFICATION: Concrete wheelguard OPUS PID:
LATITUDE: 36° 3.2' N ( 36.05372) LONGITUDE: 76° 41.0' W ( -76.68358)
The bench mark is a disk set flush in drill hole, 4.3 m (14.1 ft) southeast of
the centerline of US 17 and .3 m (1.0 ft) west of end of wheel guard and .2 m
(0.7 ft) NNW of SE end of bridge guard rail. The mark is 1.0 ft above centerline
of highway.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 6 of 7
Station ID: 8651817 PUBLICATION DATE: 12/04/2012
Name: EDENHOUSE POINT
NC
NOAA Chart: 12205 Latitude: 36° 3.3' N ( 36.05503)
USGS Quad: EDENOUSE Longitude: 76° 41.1' W ( -76.68425)
T I D A L D A T U M S
Tidal datums at EDENHOUSE POINT based on:
LENGTH OF SERIES: 3 MONTHS
TIME PERIOD: May 2012 - July 2012
TIDAL EPOCH: 1983-2001
CONTROL TIDE STATION: 8652587 OREGON INLET MARINA, PAMLICO SOUND
Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in METERS:
MEAN HIGHER HIGH WATER MHHW = 0.133
MEAN HIGH WATER MHW = 0.122
North American Vertical Datum NAVD88 = 0.113
MEAN TIDE LEVEL MTL = 0.072
MEAN SEA LEVEL MSL = 0.071
MEAN LOW WATER MLW = 0.021
MEAN LOWER LOW WATER MLLW = 0.000
North American Vertical Datum (NAVD88)
Bench Mark Elevation Information In METERS above:
Stamping or Designation MLLW MHW
P 211 1979 1.266 1.144
1817 A 2012 1.112 0.990
1817 B 2012 1.188 1.066
TOUR 1980 1.379 1.257
CHO-1 1974 3.338 3.216
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 7 of 7
Station ID: 8651817 PUBLICATION DATE: 12/04/2012
Name: EDENHOUSE POINT
NC
NOAA Chart: 12205 Latitude: 36° 3.3' N ( 36.05503)
USGS Quad: EDENOUSE Longitude: 76° 41.1' W ( -76.68425)
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.