U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Datums Page Page 1 of 5
PUBLICATION DATE: 06/29/1982
Station ID: 8638654 SUPERCEDED DATE: 04/21/2003
Name: NORFOLK AMC, ELIZABETH RIVER
VIRGINIA
NOAA Chart: 12221 Latitude: 36° 51.1' N
USGS Quad: NORFOLK NORTH Longitude: 76° 17.9' W
To reach the tidal bench marks proceed to the National Ocean Surveys Atlantic
Marine Center, located at 439 West York Street, Norfolk, Virginia, on the
Elizabeth River. The bench marks are located near the southeast corner of the
dock and along the parking area. The tide gage and staff were located on the
southeast corner of the dock.
T I D A L B E N C H M A R K S
PRIMARY BENCH MARK STAMPING: BOLE NO 1 1961
MONUMENTATION: Survey Disk VM#: 3469
AGENCY: PID#: FX0141
SETTING CLASSIFICATION: Concrete Bulkheada
The bench mark is set flush in the top of a concrete bulkhead at the southeast
corner of the dock, 32.8 feet (10.0 m) south of the southeast corner of Building
#2, 15.5 feet (4.7 m) west of the centerline of a gate, 2.5 feet (0.8 m) east of
the center of a 8-inch high docking cleat, 2.0 feet (0.6 m) west of the corner
post of the fence, and 2.0 feet (0.6 m) above level of parking area.
BENCH MARK STAMPING: BOLE 1961
MONUMENTATION: Survey Disk VM#: 3468
AGENCY: PID#: FX0140
SETTING CLASSIFICATION: Concrete Foundation of a Bollard
The bench mark is set flush in the concrete foundation of a 6x6 bollard, 24.5
feet (7.5 m) northwest of the centerline of a gate, 16.8 feet (5.1 m) south of
the southeast corner of Building #2, 16.1 feet ((4.9 m) north of Bench Mark Bole
N0 1 1961, and is 0.2 foot (0.1 m) above level of parking area.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 2 of 5
PUBLICATION DATE: 06/29/1982
Station ID: 8638654 SUPERCEDED DATE: 04/21/2003
Name: NORFOLK AMC, ELIZABETH RIVER
VIRGINIA
NOAA Chart: 12221 Latitude: 36° 51.1' N
USGS Quad: NORFOLK NORTH Longitude: 76° 17.9' W
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: BOLE NO 2 1961
MONUMENTATION: Survey Disk VM#: 3470
AGENCY: PID#: FX0139
SETTING CLASSIFICATION: Concrete Foundation
The bench mark is set flush in concrete foundation of the westernmost bollard at
the pier, 200 feet (61 m) west of Bench Mark Bole 1961, 100 feet (30 m)
southwest of the southwest corner of Building #1, 18.0 feet (5.5 m) north of the
edge of the seawall and 0.2 foot (0.1 m) above level of parking area.
BENCH MARK STAMPING: L 452 1971
MONUMENTATION: Survey Disk VM#: 3471
AGENCY: PID#: FX0134
SETTING CLASSIFICATION: Unspecified Deep Rod Mark
The bench mark is located at the north portion of the dock, 104 feet (32 m)
north of the northeast corner of Building #1, 13.2 feet (4.0 m) east of a
bollard with a 6 by 6 concrete foundation, 0.5 foot (0.2 m) behind the curbing
and 0.5 foot (0.2 m) above level of parking area.
BENCH MARK STAMPING: 8654 E 1979
MONUMENTATION: Survey Disk VM#: 6040
AGENCY: PID#: FX2157
SETTING CLASSIFICATION: Concrete Foundation
The bench mark is located at the westernmost portion of the dock, set flush in
the 6by 6 concrete foundation of a bollard, 100 feet (30 m) north northeast of
the southwest corner of Building #1, 75 feet (23 m) southwest of the northwest
corner of Building #1, 33.0 feet (10.1 m) east of the west edge of the bulkhead,
16.8 feet (5.1 m) north of the south edge of the bulkhead, 1.4 feet (0.43 m)
southwest of the southwest corner of the bollard, and 0.5 foot (0.2 m) above
level of parking area.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 3 of 5
PUBLICATION DATE: 06/29/1982
Station ID: 8638654 SUPERCEDED DATE: 04/21/2003
Name: NORFOLK AMC, ELIZABETH RIVER
VIRGINIA
NOAA Chart: 12221 Latitude: 36° 51.1' N
USGS Quad: NORFOLK NORTH Longitude: 76° 17.9' W
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: EMPLOYEE OF THE YEAR SKIP FRANK
P. MARGIOTTA 78
MONUMENTATION: Survey Disk VM#: 6041
AGENCY: PID:
SETTING CLASSIFICATION: Concrete Post
The bench mark is set flush in concrete at the north entrance to Building #1,
77.6 feet (23.7 m) southwest of the entrance to guard house, 24.5 feet (7.5 m)
north of the north entrance to Building #1, and 5.6 feet (1.7 m) north of the
flagpole.
BENCH MARK STAMPING: UNSTAMPED 1
MONUMENTATION: Survey Disk VM#: 6042
AGENCY: PID:
SETTING CLASSIFICATION: Galvanized Steel Rod
The bench mark is a standard disk, unstamped located 30.8 feet (9.4 m) north of
the centerline of Front Street, 4.1 feet (1.2 m) northwest of southwest corner
of gate to storage field on Front Street and 3.4 feet (1.0 m) east of the
southeast corner of corrugated metal garage.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 4 of 5
PUBLICATION DATE: 06/29/1982
Station ID: 8638654 SUPERCEDED DATE: 04/21/2003
Name: NORFOLK AMC, ELIZABETH RIVER
VIRGINIA
NOAA Chart: 12221 Latitude: 36° 51.1' N
USGS Quad: NORFOLK NORTH Longitude: 76° 17.9' W
T I D A L D A T U M S
Tidal datums at NORFOLK AMC, ELIZABETH RIVER based on:
LENGTH OF SERIES: 12 MONTHS
TIME PERIOD: JANUARY - DECEMBER 1973
TIDAL EPOCH: 1960-1978
CONTROL TIDE STATION: 8638610 HAMPTON ROADS
Elevations of tidal datums referred to Mean Low Water (MLW), in FEET:
HIGHEST OBSERVED WATER LEVEL (03/21/1973) = 5.82
MEAN HIGHER HIGH WATER MHHW = 2.77
MEAN HIGH WATER MHW = 1.38
* NATIONAL GEODETIC VERTICAL DATUM NGVD29 = 1.17
MEAN LOW WATER MLW = 0.00
LOWEST OBSERVED WATER LEVEL (01/27/1978) = -2.48
* NGVD reference based on adjustment of 1973 and NOS levels of 1971-1979.
North American Vertical Datum (NAVD88)
Bench Mark Elevation Information In FEET above:
Stamping or Designation MLW MHW
BOLE NO 1 1961 10.17 7.40
BOLE 1961 9.65 6.88
BOLE NO 2 1961 9.69 6.92
L 452 1971 10.16 7.39
8654 E 1979 10.00 7.23
EMPLOYEE OF THE YEAR SKIP FRANK P.
MARGIOTTA 78 9.27 6.50
UNSTAMPED 1 9.41 6.64
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 5 of 5
PUBLICATION DATE: 06/29/1982
Station ID: 8638654 SUPERCEDED DATE: 04/21/2003
Name: NORFOLK AMC, ELIZABETH RIVER
VIRGINIA
NOAA Chart: 12221 Latitude: 36° 51.1' N
USGS Quad: NORFOLK NORTH Longitude: 76° 17.9' 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.