U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Datums Page Page 1 of 7
Station ID: 8655151 PUBLICATION DATE: 09/11/2023
Name: CEDAR ISLAND
NC
NOAA Chart: 11550 Latitude: 35° 1.1' N ( 35.01894)
USGS Quad: NORTH BAY Longitude: 76° 18.9' W ( -76.31431)
To reach the tidal bench marks from the intersection of US Highway 70 and NC
Highway 12, proceed northeasterly on NC Highway 12 for 19.16 km (11.9 mi) to the
Cedar Island Ferry Terminal. Four of the bench marks are located between the
Toll Booth and the ferry docks. The other two bench marks are located on the
northwest side of NC Highway 12 between the Toll Booth and the curve 0.40 km
(0.25 mi) southwest of the Toll Booth. The tide sensor is located on the
northwesternmost of four ferry docks at the Cedar Island Ferry Terminal.
T I D A L B E N C H M A R K S
PRIMARY BENCH MARK STAMPING: CAR 99 2009
DESIGNATION: CAR 99
MONUMENTATION: Flange-encased Rod VM#: 24664
AGENCY: North Carolina Geodetic Survey (NCGS) IDB PID#:
SETTING CLASSIFICATION: Stainless steel rod in sleeve OPUS PID#: DM4005
LATITUDE: 35° 1.0' N ( 35.01744) LONGITUDE: 76° 18.9' W ( -76.31483)
The mark is a deep rod located 23.4 m (76.8 ft) east of a light post in parking
lot, 23.3 m (75.9 ft) south of a light post in parking lot, 21.5 m (70.5 ft) NNE
of a power pole, both with reference tags, 11.2 m (36.6 ft) SE of the SE edge of
parking lot, and 10.4 m (34.2 ft) NW of a fence post at the intersection of two
fences. The mark is level with the asphalt parking lot and is flush with the
ground.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 2 of 7
Station ID: 8655151 PUBLICATION DATE: 09/11/2023
Name: CEDAR ISLAND
NC
NOAA Chart: 11550 Latitude: 35° 1.1' N ( 35.01894)
USGS Quad: NORTH BAY Longitude: 76° 18.9' W ( -76.31431)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 5151 A 1977
DESIGNATION: 865 5151 A TIDAL
MONUMENTATION: Tidal Station disk VM#: 3553
AGENCY: National Ocean Survey (NOS) IDB PID#:
SETTING CLASSIFICATION: Concrete footing OPUS PID#: DM4006
LATITUDE: 35° 1.1' N ( 35.01780) LONGITUDE: 76° 18.9' W ( -76.31519)
The bench mark is a disk set flush in a concrete footing for an antenna, located
23.0 m (75.3 ft) SW of an antenna pole with reference tag, 18.5 m (60.7 ft) NE
of the CORS antenna base, 15.4 m (50.6 ft) SE of a fiberglass light pole, 12.9 m
(42.4 ft) NNE of an antenna pole with reference tag, and 10.2 m (33.4 ft) NW of
a fiberglass light pole. The mark is now recessed 1 inch below the ground and is
about level with the parking lot.
BENCH MARK STAMPING: 5151 B 1977
DESIGNATION: 865 5151 B TIDAL
MONUMENTATION: Tidal Station disk VM#: 3554
AGENCY: National Ocean Survey (NOS) IDB PID#:
SETTING CLASSIFICATION: Concrete slab OPUS PID#: AC7508
LATITUDE: 35° 1.1' N ( 35.01750) LONGITUDE: 76° 18.9' W ( -76.31548)
The bench mark is a disk set flush in a concrete slab in front of the ferry
operations building, located 24.0 m (78.6 ft) NW of the SW corner of the ticket
booth, 20.1 m (65.9 ft) SE of a power pole with reference tag, 9.6 m (31.4 ft)
SW of a telephone pedestal (351EER 1), 5.2 m (17.2 ft) NE of a 38 cm (15 inch)
oak with reference tag, and 4.8 m (15.7 ft) east of the NE corner of a white
picket fence. The mark is now recessed 1 inch below the ground and is about
level with the access road.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 3 of 7
Station ID: 8655151 PUBLICATION DATE: 09/11/2023
Name: CEDAR ISLAND
NC
NOAA Chart: 11550 Latitude: 35° 1.1' N ( 35.01894)
USGS Quad: NORTH BAY Longitude: 76° 18.9' W ( -76.31431)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 5151 E 1977
DESIGNATION: 865 5151 E TIDAL
MONUMENTATION: Tidal Station disk VM#: 3557
AGENCY: National Ocean Survey (NOS) IDB PID#:
SETTING CLASSIFICATION: Concrete porch OPUS PID:
LATITUDE: 35° 1.0' N ( 35.01671) LONGITUDE: 76° 19.0' W ( -76.31660)
The bench mark is a disk set flush in a concrete porch at the NE corner of the
shopping complex building, located 26.2 m (86.1 ft) NW of the centerline of NC
Highway 12, 6.4 m (20.9 ft) WSW of the NE building corner, 2.6 m (8.40 ft) NW of
the NE corner of the slab, and 0.20 m (0.65 ft) SW of the NE edge of the porch
slab.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 4 of 7
Station ID: 8655151 PUBLICATION DATE: 09/11/2023
Name: CEDAR ISLAND
NC
NOAA Chart: 11550 Latitude: 35° 1.1' N ( 35.01894)
USGS Quad: NORTH BAY Longitude: 76° 18.9' W ( -76.31431)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: D 239 1947
DESIGNATION: D 239
MONUMENTATION: Bench Mark disk VM#: 24663
AGENCY: US Coast and Geodetic Survey (CGS) IDB PID#:
SETTING CLASSIFICATION: Concrete monument OPUS PID:
LATITUDE: 35° 0.9' N ( 35.01467) LONGITUDE: 76° 19.1' W ( -76.31822)
The mark is a disk set in a concrete monument located 39.8 m (130.6 ft) west of
the centerline of NC Highway 12, 8.8 m (28.8 ft) WNW of a billboard sign post,
6.4 m (21.1 ft) south of a 33 cm (13-inch) forked oak, all with reference tags,
5.9 m (19.5 ft) WSW of a power pole, and 2.0 m (6.5 ft) ENE of a property iron.
The mark is flush with the ground and is about level with NC Highway 12.
BENCH MARK STAMPING: 5151 F 2022
DESIGNATION: 865 5151 F
MONUMENTATION: Bench Mark disk VM#: 24665
AGENCY: North Carolina Geodetic Survey (NCGS) IDB PID#:
SETTING CLASSIFICATION: Concrete Seawall OPUS PID:
LATITUDE: 35° 1.1' N ( 35.01888) LONGITUDE: 76° 18.9' W ( -76.31433)
The mark is located on the top of the concrete seawall just NW of the loading
dock, located 30.2 m (99.0 ft) NW of a chain link fence at the ferry dock, 14.4
m (47.4 ft) SSE of a 15" wood bollard with reference tag, 8.2 m (26.8 ft) north
of the southernmost gate post, 3.6 m (11.8 ft) ENE of the northernmost gate
post, and 0.26 m (0.85 ft) NNW of the south end of the concrete seawall.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 5 of 7
Station ID: 8655151 PUBLICATION DATE: 09/11/2023
Name: CEDAR ISLAND
NC
NOAA Chart: 11550 Latitude: 35° 1.1' N ( 35.01894)
USGS Quad: NORTH BAY Longitude: 76° 18.9' W ( -76.31431)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 5151 G 2023
DESIGNATION: 865 5151 G
MONUMENTATION: Bench Mark disk VM#: 24666
AGENCY: North Carolina Geodetic Survey (NCGS) IDB PID#:
SETTING CLASSIFICATION: Concrete Seawall OPUS PID:
LATITUDE: 35° 1.1' N ( 35.01833) LONGITUDE: 76° 18.8' W ( -76.31350)
The mark is a disk on the top of the concrete seawall approximately 9.1 m (30
ft) NW of the end of the seawall, 7.5 m (24.5 ft) NNE of a 6x6 inch (15 cm)
wooden post, 7.0 m (23.1 ft) SE of the center of a gate, 4.8 m (15.6 ft) ENE of
a light pole, 3.5 m (11.5 ft) SSE of the SE edge of a wooden loading dock, and
0.4 m (1.3 ft) SSW of the face of the seawall.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 6 of 7
Station ID: 8655151 PUBLICATION DATE: 09/11/2023
Name: CEDAR ISLAND
NC
NOAA Chart: 11550 Latitude: 35° 1.1' N ( 35.01894)
USGS Quad: NORTH BAY Longitude: 76° 18.9' W ( -76.31431)
T I D A L D A T U M S
Tidal datums at CEDAR ISLAND based on:
LENGTH OF SERIES: 7 MONTHS
TIME PERIOD: September 2022 - March 2023
TIDAL EPOCH: 1983-2001
CONTROL TIDE STATION: 8654467 USCG STATION HATTERAS, PAMLICO SOUND
Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in METERS:
MEAN HIGH WATER MHW = 0.124
MEAN HIGHER HIGH WATER MHHW = 0.118
North American Vertical Datum NAVD88 = 0.107
MEAN TIDE LEVEL MTL = 0.072
MEAN SEA LEVEL MSL = 0.055
MEAN LOW WATER MLW = 0.020
MEAN LOWER LOW WATER MLLW = 0.000
North American Vertical Datum (NAVD88)
Bench Mark Elevation Information In METERS above:
Stamping or Designation MLLW MHW
CAR 99 2009 1.921 1.797
5151 A 1977 1.837 1.713
5151 B 1977 1.733 1.609
5151 E 1977 1.656 1.532
D 239 1947 0.942 0.818
5151 F 2022 1.919 1.795
5151 G 2023 1.907 1.783
Foot Notes:
Bench mark 5151 G 2023 is based on one differential leveling connection and does
not meet the quality control standards of the NOS. Therefore, caution should be
used when deriving elevations for this mark.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 7 of 7
Station ID: 8655151 PUBLICATION DATE: 09/11/2023
Name: CEDAR ISLAND
NC
NOAA Chart: 11550 Latitude: 35° 1.1' N ( 35.01894)
USGS Quad: NORTH BAY Longitude: 76° 18.9' W ( -76.31431)
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.