U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Datums Page Page 1 of 5
PUBLICATION DATE: 06/06/1990
Station ID: 8656590 SUPERCEDED DATE: 04/21/2003
Name: ATLANTIC BEACH, ATLANTIC OCEAN
NORTH CAROLINA
NOAA Chart: 11547 Latitude: 34° 41.6' N
USGS Quad: BEAUFORT Longitude: 76° 42.7' W
To reach the tidal bench marks from the Atlantic Beach Post Office, proceed
south on Morehead Avenue for 0.3 mile (0.5 km) to Fort Macon Boulevard, then
east on Fort Macon Boulevard for 1.6 miles (2.6 km) to Henderson Boulevard, turn
right onto Henderson Boulevard and go south for 0.2 mile (0.3 km) to Triple S
Fishing Pier. The bench marks are near the pier and along Henderson Boulevard.
The tide gage and electric tape gage were about 750 feet (229 m) south of the
inshore end of pier.
T I D A L B E N C H M A R K S
PRIMARY BENCH MARK STAMPING: 6590 B 1976
MONUMENTATION: Survey Disk VM#: 3564
AGENCY: PID#: AC7539
SETTING CLASSIFICATION: Copper-clad Steel Rod
The bench mark is at the SW corner of Henderson Boulevard and Raleigh Road, 34.0
feet (10.4 m) west of the centerline of Henderson Boulevard, 26.0 feet (7.9 m)
south of the centerline of Raleigh Road, and 1.4 feet (0.4 m) north of a wooden
street marker. The bench mark is crimped to a copper-clad steel rod driven an
unspecified depth, and surrounded by concrete.
BENCH MARK STAMPING: NO 4 1960
MONUMENTATION: Survey Disk VM#: 3561
AGENCY: PID#: EA0180
SETTING CLASSIFICATION: Concrete Apron
The bench mark is set in the concrete apron surrounding the Triple S Pier snack
bar building, 33.5 feet (10.2 m) west of the extended centerline of Henderson
Boulevard, 31.0 feet (9.4 m) east of the NW corner of the attached garage, and
0.4 foot (0.1 m) north of the building.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 2 of 5
PUBLICATION DATE: 06/06/1990
Station ID: 8656590 SUPERCEDED DATE: 04/21/2003
Name: ATLANTIC BEACH, ATLANTIC OCEAN
NORTH CAROLINA
NOAA Chart: 11547 Latitude: 34° 41.6' N
USGS Quad: BEAUFORT Longitude: 76° 42.7' W
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: NO 5 1960
MONUMENTATION: Survey Disk VM#: 3562
AGENCY: PID#: EA0179
SETTING CLASSIFICATION: Concrete Slab
The bench mark is on the east side of Henderson Boulevard, 550 feet (168 m)
north of Triple S Pier, 81 feet (25 m) south of the centerline of Raleigh
Avenue, 49.4 feet (15.1 m) east of the centerline of Henderson Boulevard, 1 foot
(0.3 m) west of a pink cinder block building, and 0.3 foot (0.1 m) below the
surface of the patio.
BENCH MARK STAMPING: NO 6 1960
MONUMENTATION: Survey Disk VM#: 3563
AGENCY: PID#: EA0177
SETTING CLASSIFICATION: Concrete Slab
The bench mark is set in a concrete slab beneath a second story overhang on the
east side of Henderson Boulevard, 0.15 mile (0.24 km) north of Triple S Pier,
113 feet (34 m) south of the centerline of Winston Avenue, and 46 feet (14 m)
east of the centerline of Henderson Boulevard.
BENCH MARK STAMPING: 6590 C 1976
MONUMENTATION: Survey Disk VM#: 3565
AGENCY: PID#: AC7488
SETTING CLASSIFICATION: Copper-clad Steel Rod
The bench mark is on the west side of Henderson Boulevard between Fort Macon and
Raleigh Roads, 32.5 feet (9.9 m) west of the centerline of Henderson Boulevard,
24.4 feet (7.4 m) south of an east-west tar and gravel road, and 1.3 feet (0.4
m) east of a wooden street marker. The bench mark is crimped to a copper-clad
steel rod driven 45 feet (14 m), and surrounded by concrete.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 3 of 5
PUBLICATION DATE: 06/06/1990
Station ID: 8656590 SUPERCEDED DATE: 04/21/2003
Name: ATLANTIC BEACH, ATLANTIC OCEAN
NORTH CAROLINA
NOAA Chart: 11547 Latitude: 34° 41.6' N
USGS Quad: BEAUFORT Longitude: 76° 42.7' W
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 6590 D 1976
MONUMENTATION: Survey Disk VM#: 3566
AGENCY: PID#: AC7538
SETTING CLASSIFICATION: Copper-clad Steel Rod
The bench mark is at the SE intersection of Henderson Boulevard and Fort Macon
Road, 49.6 feet (15.1 m) south of the centerline of Fort Macon Road, 32.3 feet
(9.8 m) east of the centerline of Henderson Boulevard, and 10.5 feet (3.2 m) NW
of the NW corner of a building. The bench mark is crimped to a copper- clad
steel rod driven 35 feet (11 m), and surrounded by concrete.
BENCH MARK STAMPING: 6590 E 1981
MONUMENTATION: Survey Disk VM#: 3567
AGENCY: PID:
SETTING CLASSIFICATION: Concrete Sea Wall
The bench mark is set flush in a concrete sea wall near the Triple S Marina at
the north end of Henderson Boulevard, 62.9 feet (19.2 m) NE of the centerline of
the road leading around the west side of the marina, 39.0 feet (11.9 m) west of
the center of the fuel dock, and 6.1 feet (1.9 m) north of the NW corner of the
addition to the store.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 4 of 5
PUBLICATION DATE: 06/06/1990
Station ID: 8656590 SUPERCEDED DATE: 04/21/2003
Name: ATLANTIC BEACH, ATLANTIC OCEAN
NORTH CAROLINA
NOAA Chart: 11547 Latitude: 34° 41.6' N
USGS Quad: BEAUFORT Longitude: 76° 42.7' W
T I D A L D A T U M S
Tidal datums at ATLANTIC BEACH, ATLANTIC OCEAN based on:
LENGTH OF SERIES: 14 MONTHS
TIME PERIOD: APRIL 1982-NOVEMBER 1983
TIDAL EPOCH: 1960-1978
CONTROL TIDE STATION: 8656483 BEAUFORT
Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in FEET:
HIGHEST OBSERVED WATER LEVEL (11/13/1981) = 6.84
MEAN HIGHER HIGH WATER MHHW = 4.28
MEAN HIGH WATER MHW = 3.96
MEAN TIDE LEVEL MTL = 2.10
* NATIONAL GEODETIC VERTICAL DATUM NGVD29 = 1.75
MEAN LOW WATER MLW = 0.25
MEAN LOWER LOW WATER MLLW = 0.00
LOWEST OBSERVED WATER LEVEL (01/14/1982) = -2.11
* NGVD reference based on elevations published in Quad 340764, 1964, and NOS
leveling of 1985.
North American Vertical Datum (NAVD88)
Bench Mark Elevation Information In FEET above:
Stamping or Designation MLLW MHW
6590 B 1976 12.06 8.10
NO 4 1960 13.66 9.70
NO 5 1960 12.88 8.92
NO 6 1960 15.74 11.78
6590 C 1976 13.48 9.52
6590 D 1976 8.58 4.62
6590 E 1981 6.99 3.03
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 5 of 5
PUBLICATION DATE: 06/06/1990
Station ID: 8656590 SUPERCEDED DATE: 04/21/2003
Name: ATLANTIC BEACH, ATLANTIC OCEAN
NORTH CAROLINA
NOAA Chart: 11547 Latitude: 34° 41.6' N
USGS Quad: BEAUFORT Longitude: 76° 42.7' W
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 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.