U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Datums Page Page 1 of 5
Station ID: 8638999 PUBLICATION DATE: 07/26/2004
Name: CAPE HENRY
VA
NOAA Chart: 122254 Latitude: 36° 55.8' N ( 36.93000)
USGS Quad: CAPE HENRY Longitude: 76° 0.4' W ( -76.00670)
To reach the tidal bench marks from the intersection of U.S. Highways 460 and 60
in Norfolk, proceed east on U.S. Highway 60 (Shore Drive) for 22.0 km (13.7 mi),
then proceed north on Atlantic Avenue for 3.2 km (2.0 mi) to the entrance to Ft.
Story Military Reservation, which is marked by a sign on the divided part of the
highway. The bench marks are near the Coast Guard Lighthouse. The tide gage
and staff were on pilings offshore.
T I D A L B E N C H M A R K S
PRIMARY BENCH MARK STAMPING: 8999 C 1982
DESIGNATION: 863 8999 C
MONUMENTATION: Tidal Station disk VM#: 3492
AGENCY: National Ocean Service (NOS) IDB PID#:
SETTING CLASSIFICATION: Concrete foundation OPUS PID:
LATITUDE: ' °deg (0) LONGITUDE: ' °deg (0)
The primary bench mark is a disk set flush in a concrete foundation with a metal
core supporting a septic tank, 115.37 m (378.5 ft) east of bench mark 8999 B
1982, and 28 m (93 ft) NW of the NE corner of the Coast Guard building which
houses the fog signal at the NE corner of the fenced-in property.
BENCH MARK STAMPING: NO 1 1932
DESIGNATION: 863 8999 TIDAL 1
MONUMENTATION: Reference Mark disk VM#: 3489
AGENCY: US Coast and Geodetic Survey
(USC&GS) IDB PID#:
SETTING CLASSIFICATION: Concrete step OPUS PID:
LATITUDE: 36° 55.8' N ( 36.93000) LONGITUDE: 76° 0.4' W ( -76.00670)
The bench mark is a disk set flush in the concrete step foundation on the south
side of the 1879 Cape Henry Lighthouse, 132 m (433 ft) south of the SE side of
Pier 11 Club, and 115 m (378 ft) WSW of bench mark 8999 D 1982.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 2 of 5
Station ID: 8638999 PUBLICATION DATE: 07/26/2004
Name: CAPE HENRY
VA
NOAA Chart: 122254 Latitude: 36° 55.8' N ( 36.93000)
USGS Quad: CAPE HENRY Longitude: 76° 0.4' W ( -76.00670)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 8999 A 1982
DESIGNATION: 863 8999 A
MONUMENTATION: Tidal Station disk VM#: 3490
AGENCY: National Ocean Service (NOS) IDB PID#:
SETTING CLASSIFICATION: Concrete step OPUS PID:
LATITUDE: ' °deg (0) LONGITUDE: ' °deg (0)
The bench mark is a disk set flush in the concrete step on the north side of
Pier 11 Club near the west end of the building, 192 m (629 ft) north of bench
mark NO 1 1932, 23 m (77 ft) SE of telephone pole #G73, and 10.52 m (34.5 ft)
NNW of the square section of an exposed brick chimney on the north side of the
building.
BENCH MARK STAMPING: 8999 B 1982
DESIGNATION: 863 8999 B
MONUMENTATION: Tidal Station disk VM#: 3491
AGENCY: National Ocean Service (NOS) IDB PID#:
SETTING CLASSIFICATION: Concrete foundation OPUS PID:
LATITUDE: ' °deg (0) LONGITUDE: ' °deg (0)
The bench mark is a disk set flush in a large concrete foundation supporting an
air conditioner unit at the east end of Pier 11 Club, just west of the Coast
Guard light station, 132 m (433 ft) NNW of the south side of the 1879
lighthouse, and 48.62 m (159.5 ft) NNW of the NW corner of a concrete post and
steel pipe fence bordering the Coast Guard property.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 3 of 5
Station ID: 8638999 PUBLICATION DATE: 07/26/2004
Name: CAPE HENRY
VA
NOAA Chart: 122254 Latitude: 36° 55.8' N ( 36.93000)
USGS Quad: CAPE HENRY Longitude: 76° 0.4' W ( -76.00670)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 8999 D 1982
DESIGNATION: 863 8999 D
MONUMENTATION: Tidal Station disk VM#: 3493
AGENCY: National Ocean Service (NOS) IDB PID#:
SETTING CLASSIFICATION: Concrete foundation OPUS PID:
LATITUDE: ' °deg (0) LONGITUDE: ' °deg (0)
The bench mark is a disk set flush in a prominent concrete foundation with two
pieces of protruding threaded rod located in the SE of the NE corner of the
fenced-in Coast Guard property, 29.72 m (97.5 ft) SE of the SE end of the garage
in the NE corner of the Coast Guard property, and 16 m (53 ft) east of the
fenced-in Coast Guard property.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 4 of 5
Station ID: 8638999 PUBLICATION DATE: 07/26/2004
Name: CAPE HENRY
VA
NOAA Chart: 122254 Latitude: 36° 55.8' N ( 36.93000)
USGS Quad: CAPE HENRY Longitude: 76° 0.4' W ( -76.00670)
T I D A L D A T U M S
Tidal datums at CAPE HENRY based on:
LENGTH OF SERIES: 1 MONTH
TIME PERIOD: June 1982 - June 1982
TIDAL EPOCH: 1983-2001
CONTROL TIDE STATION: 8638863 CHESAPEAKE BAY BRIDGE TUNNEL
Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in METERS:
MEAN HIGHER HIGH WATER MHHW = 1.066
MEAN HIGH WATER MHW = 0.988
MEAN SEA LEVEL MSL = 0.519
MEAN TIDE LEVEL MTL = 0.513
MEAN LOW WATER MLW = 0.038
MEAN LOWER LOW WATER MLLW = 0.000
North American Vertical Datum (NAVD88)
Bench Mark Elevation Information In METERS above:
Stamping or Designation MLLW MHW
8999 C 1982 2.984 1.996
NO 1 1932 4.219 3.231
8999 A 1982 3.147 2.159
8999 B 1982 3.619 2.631
8999 D 1982 4.857 3.869
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 5 of 5
Station ID: 8638999 PUBLICATION DATE: 07/26/2004
Name: CAPE HENRY
VA
NOAA Chart: 122254 Latitude: 36° 55.8' N ( 36.93000)
USGS Quad: CAPE HENRY Longitude: 76° 0.4' W ( -76.00670)
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.