U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Datums Page Page 1 of 7
Station ID: 8654875 PUBLICATION DATE: 01/15/2013
Name: RIVER DUNES
NC
NOAA Chart: 11541 Latitude: 35° 5.1' N ( 35.08528)
USGS Quad: BROAD CREEK, NC Longitude: 76° 36.0' W ( -76.60044)
To reach the tidal bench marks from the intersection of Highway 55 and 304 in
Bayboro, North Carolina, proceed SE on Highway 55 for 8.1 km (5.0 mi) to the
intersection with N Trent Road in Merritt, North Carolina, turn left on N Trent
Road and proceed SE for 5.3 km (3.3 mi) to its termination with Straight Road,
turn right on Straight Road and proceed south for 0.8 km (0.5 mi) to its
intersection with Pamlico Road, turn left on Pamlico Road and proceed NE for 2.7
km (1.7 mi) to its termination with Orchard Creek Road, turn right on Orchard
Creek Road and proceed SE for 2.4 km (1.5 mi) to Old Lighthouse Road , turn left
and proceed NE?ly for 2.8 km (1.7 mi) to its termination with Harborside Road,
turn right on Harborside Road and proceed NE for 0.7 km (0.4 mi) to a parking
lot on the left. The bench marks are located along Harborside Road and the
waterfront area. The tide gauge is located near the fuel dock by the River
Dunes Harbor Club.
T I D A L B E N C H M A R K S
PRIMARY BENCH MARK STAMPING: 4875 A 2012
DESIGNATION: 865 4875 A
MONUMENTATION: Metal Rod VM#: 20412
AGENCY: NOS IDB PID#:
SETTING CLASSIFICATION: OPUS PID#: BBCS58
LATITUDE: 35° 5.1' N ( 35.08569) LONGITUDE: 76° 36.1' W ( -76.60100)
The primary bench mark is a flange-encased rod set in a garden bed near the
intersection of ballast point road and East Harborside Road, 21.50 m (70.5 ft)
south of the corner of a white fence, 20.93 m (68.7 ft) southwest of a fire
hydrant, 14.76 m (48.4 ft) west of the west corner of a green utility box, 11.70
m (38.4 ft) southwest of the centerline of East Harborside Road, 10.30 m (33.8
ft) northeast of the seaward edge of the seawall, 8.25 m (27.1 ft) southwest of
the top back of curb of East Harborside Road and 1.90 m (6.2 ft) north-northeast
of a 7 cm (3 inch) diameter tree. The datum point is set 18 cm (0.6 ft) below
grade, being the top of a stainless steel rod driven 20.7 m (68 ft) to refusal,
in a sleeve extending to a depth of 0.9 m (3.0 ft) and encased in a 5-inch
National Geodetic Survey logo cap with concrete kickblock.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 2 of 7
Station ID: 8654875 PUBLICATION DATE: 01/15/2013
Name: RIVER DUNES
NC
NOAA Chart: 11541 Latitude: 35° 5.1' N ( 35.08528)
USGS Quad: BROAD CREEK, NC Longitude: 76° 36.0' W ( -76.60044)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 4875 B 2012
DESIGNATION: 865 4875 B
MONUMENTATION: Metal Rod VM#: 20413
AGENCY: NOS IDB PID#:
SETTING CLASSIFICATION: OPUS PID:
LATITUDE: 35° 5.2' N ( 35.08606) LONGITUDE: 76° 36.1' W ( -76.60161)
The bench mark is a flange-encased rod set in a garden bed, 17.60 m (57.7 ft)
west-southwest of a white fence corner, 12.85 m (42.2 ft) south-southeast of the
end of curb, 11.25 m (36.9 ft) north-northeast of the seaward edge of the
seawall, 9.80 m (32.2 ft) southwest of the centerline of the road, 6.62 m (21.7
ft) southwest of the top back of curb and 6.00 m (19.7 ft) northwest of a 8 cm
(3 inch) diameter pine tree. The datum point is set 5 cm (0.2 ft) below grade,
being the top of a stainless steel rod driven 19.2 m (63 ft) to refusal, in a
sleeve extending to a depth of 0.9 m (3.0 ft) and encased in a 5-inch NOS logo
cap with concrete kickblock.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 3 of 7
Station ID: 8654875 PUBLICATION DATE: 01/15/2013
Name: RIVER DUNES
NC
NOAA Chart: 11541 Latitude: 35° 5.1' N ( 35.08528)
USGS Quad: BROAD CREEK, NC Longitude: 76° 36.0' W ( -76.60044)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 4875 C 2012
DESIGNATION: 865 4875 C
MONUMENTATION: Metal Rod VM#: 20414
AGENCY: NOS IDB PID#:
SETTING CLASSIFICATION: OPUS PID#: BBCS59
LATITUDE: 35° 5.2' N ( 35.08592) LONGITUDE: 76° 36.1' W ( -76.60233)
The bench mark is a flange-encased rod set in the grassy area along the south
side of the channel leading to the marina, 68.25 m (223.9 ft) southeast of bench
mark 865 4875 D, 42.45 m (139.3 ft) north-northwest of the first step up in the
seawall, 29.50 m (96.8 ft) north of the end of the gravel road, 26.23 m (86.1
ft) south of a 30-degree bend in the seawall, 23.60 m (77.4 ft) northeast of an
orange carsonite NOS witness post and 6.65 m (21.8 ft) west-southwest of the
seawall. The datum point is set 11 cm (0.4 ft) below grade, being the top of a
stainless steel rod driven 18.5 m (61 ft) to refusal, in a sleeve extending to a
depth of 0.9 m (3.0 ft) and encased in a 5-inch NOS logo cap with concrete
kickblock.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 4 of 7
Station ID: 8654875 PUBLICATION DATE: 01/15/2013
Name: RIVER DUNES
NC
NOAA Chart: 11541 Latitude: 35° 5.1' N ( 35.08528)
USGS Quad: BROAD CREEK, NC Longitude: 76° 36.0' W ( -76.60044)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 4875 D 2012
DESIGNATION: 865 4875 D
MONUMENTATION: Metal Rod VM#: 20415
AGENCY: NOS IDB PID#:
SETTING CLASSIFICATION: OPUS PID:
LATITUDE: 35° 5.2' N ( 35.08631) LONGITUDE: 76° 36.2' W ( -76.60292)
The bench mark is a flange-encased rod set in the grassy area along the south
side of the channel leading to the marina, 79.41 m (260.5 ft) east-southeast of
bench mark 865 4875 e, 68.25 m (223.9 ft) northwest of bench mark 865 4875 c,
48.65 m (159.6 ft) west-northwest of a bend in the seawall, 10.30 m (33.8 ft)
north-northeast of an orange carsonite NOS witness post and 5.95 m (19.5 ft)
south-southwest of the seawall. The datum point is set 10 cm (0.3 ft) below
grade, being the top of a stainless steel rod driven 18.6 m (61 ft) to refusal,
in a sleeve extending to a depth of 0.9 m (3.0 ft) and encased in a 5-inch NOS
logo cap with concrete kickblock.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 5 of 7
Station ID: 8654875 PUBLICATION DATE: 01/15/2013
Name: RIVER DUNES
NC
NOAA Chart: 11541 Latitude: 35° 5.1' N ( 35.08528)
USGS Quad: BROAD CREEK, NC Longitude: 76° 36.0' W ( -76.60044)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 4875 E 2012
DESIGNATION: 865 4875 E
MONUMENTATION: Metal Rod VM#: 20416
AGENCY: NOS IDB PID#:
SETTING CLASSIFICATION: OPUS PID:
LATITUDE: 35° 5.2' N ( 35.08669) LONGITUDE: 76° 36.2' W ( -76.60361)
The bench mark is a flange-encased rod set in the grassy area along the south
side of the channel leading to the marina, 251.6 m (825.5 ft) east-southeast of
the northwest end of the seawall, 208.4 m (684 ft) east-southeast of the no
wake sign at the channel entrance, 79.41 m (260.5 ft) west-northwest of bench
mark 865 4875 d, 20.50 m (67.3 ft) northeast of an orange carsonite NOS witness
post and 5.22 m (17.1 ft) southwest of the seaward edge of the seawall. The
datum point is set 8 cm (0.3 ft) below grade, being the top of a stainless steel
rod driven 18.6 m (61 ft) to refusal, in a sleeve extending to a depth of 0.9 m
(3.0 ft) and encased in a 5-inch NGS logo cap with concrete kickblock.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 6 of 7
Station ID: 8654875 PUBLICATION DATE: 01/15/2013
Name: RIVER DUNES
NC
NOAA Chart: 11541 Latitude: 35° 5.1' N ( 35.08528)
USGS Quad: BROAD CREEK, NC Longitude: 76° 36.0' W ( -76.60044)
T I D A L D A T U M S
Tidal datums at RIVER DUNES based on:
LENGTH OF SERIES: 3 MONTHS
TIME PERIOD: May 2012 - July 2012
TIDAL EPOCH: 1983-2001
CONTROL TIDE STATION: 8654467 USCG STATION HATTERAS, PAMLICO SOUND
Elevations of tidal datums referred to Mean Sea Level (MSL), in METERS:
MEAN SEA LEVEL MSL = 0.000
North American Vertical Datum (NAVD88)
Bench Mark Elevation Information In METERS above:
Stamping or Designation MSL
4875 A 2012 1.438
4875 B 2012 1.535
4875 C 2012 1.071
4875 D 2012 1.026
4875 E 2012 1.046
Foot Notes:
This station has been determined to be Non-tidal for tidal datum purposes.
There is either no measureable periodic rise and fall of the tide at this
location, or it may be present but inconsistent, or the periodic tide is present
and consistent, however the Mean Range of Tide (MN) is negligible, that is below
the established tidal/non-tidal threshold of 0.03m (0.10ft). Only the datum of
local Mean Sea Level (MSL) is published at these stations. For Nautical
Charting Datum applications, a non-tidal Low Water Datum (LWD) is established as
0.50ft (0.15m) below MSL.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 7 of 7
Station ID: 8654875 PUBLICATION DATE: 01/15/2013
Name: RIVER DUNES
NC
NOAA Chart: 11541 Latitude: 35° 5.1' N ( 35.08528)
USGS Quad: BROAD CREEK, NC Longitude: 76° 36.0' W ( -76.60044)
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.