U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Datums Page Page 1 of 6
PUBLICATION DATE: 04/28/1988
Station ID: 8637624 SUPERCEDED DATE: 04/21/2003
Name: GLOUCESTER POINT, YORK RIVER
VIRGINIA
NOAA Chart: 12241 Latitude: 37° 14.8' N
USGS Quad: POQUOSON WEST Longitude: 76° 30.0' W
To reach the tidal bench marks from the intersection of U.S. Highway 17 and
State Road 1206 in Gloucester Point, proceed east on State Road 1206 for 0.05
mile (0.08 km) to State Road 1208, continue south on State Road 1208 for 0.3
mile (0.5 km) to Virginia Institute of Marine Science (VIMS). The bench marks
are on the VIMS property. The tide gage and staff are located in the first
house on VIMS Laboratory Pier.
T I D A L B E N C H M A R K S
PRIMARY BENCH MARK STAMPING: 7624 F 1979
MONUMENTATION: Survey Disk VM#: 502
AGENCY: PID:
SETTING CLASSIFICATION: Concrete Platform
The bench mark is set in the SW corner of a concrete air conditioning unit
platform on the west side of Byrd Hall, 87.4 feet (26.6 m) north of the sea
wall, 10.1 feet (3.1 m) north of the entrance to the air conditioning units, 9.5
feet (2.9 m) west of the west face of the building, 1.5 feet (0.5 m) south of
the SW corner of the main air conditioning unit, and 0.4 foot (0.1 m) above the
ground.
BENCH MARK STAMPING: NO 7 1950
MONUMENTATION: Survey Disk VM#: 503
AGENCY: PID#: GV0606
SETTING CLASSIFICATION: Concrete Curb
The bench mark is set in the top of the north edge of curbing along concrete
road to VIMS Ship Pier, 35.5 feet (10.8 m) east of the east side of the wood and
metal maintenance electric shop building, 21 feet (6 m) NW of the seawall, 9.2
feet (2.8 m) SW of power pole #VEPCOXN29, 9 feet (3 m) south of the north end of
an old pipe railing, and about level with the road.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 2 of 6
PUBLICATION DATE: 04/28/1988
Station ID: 8637624 SUPERCEDED DATE: 04/21/2003
Name: GLOUCESTER POINT, YORK RIVER
VIRGINIA
NOAA Chart: 12241 Latitude: 37° 14.8' N
USGS Quad: POQUOSON WEST Longitude: 76° 30.0' W
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: NO 4 1918
MONUMENTATION: Survey Disk VM#: 504
AGENCY: PID#: GV0598
SETTING CLASSIFICATION: Concrete Block
The bench mark is set in the top of a concrete block located in the vicinity of
Hoxton Building, 196 feet (60 m) SE of the centerline of U.S. Highway 17, 26
feet (8 m) SW of the centerline of Bank Street, 16.5 feet (5.0 m) NW of the NE
corner of Hoxton Building, 3 feet (1 m) NE of the north wall of the building,
and 0.1 foot (0.03 m) above the ground.
BENCH MARK STAMPING: NO 9 1959
MONUMENTATION: Survey Disk VM#: 505
AGENCY: PID#: GV0596
SETTING CLASSIFICATION: Concrete Base
The bench mark is set flush in the top of the SW corner of the flagpole base in
the vicinity of Maury Hall, 41.0 feet (12.5 m) south of the centerline of the
steps to the driveway leading to the pier, 24.4 feet (7.4 m) west of the most
westerly end of the handrail for steps leading to the NE entrance of the Wet
Laboratory building, 23.9 feet (7.3 m) SW of the SW corner of the building, and
0.3 foot (0.1 m) above the ground.
BENCH MARK STAMPING: D 457 1971
MONUMENTATION: Survey Disk VM#: 506
AGENCY: PID#: GV0597
SETTING CLASSIFICATION: Concrete and Brick Wall
The bench mark is set vertically in the east face of the wall of Byrd Hall, 295
feet (90 m) SE of the centerline of State Road 1208, 20.0 feet (6.1 m) NW of a
concrete retaining wall along the NW bank of York River, and 0.8 foot (0.2 m) NW
of the SE corner of the building, and about 4 feet (1 m) above the sidewalk.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 3 of 6
PUBLICATION DATE: 04/28/1988
Station ID: 8637624 SUPERCEDED DATE: 04/21/2003
Name: GLOUCESTER POINT, YORK RIVER
VIRGINIA
NOAA Chart: 12241 Latitude: 37° 14.8' N
USGS Quad: POQUOSON WEST Longitude: 76° 30.0' W
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: NO 8 1950 RESET 1973
MONUMENTATION: Survey Disk VM#: 507
AGENCY: PID:
SETTING CLASSIFICATION: Concrete Curbing/Sea Wall
The bench mark is set in the top of concrete curbing which is part of the sea
wall in the vicinity of VIMS Laboratory Pier, 52 feet (16 m) east of the SE
corner of Davis Hall, 23 feet (7 m) SW of the SW corner of Wet Laboratory, 2
feet (1 m) west of landward end of the pier, and 0.7 foot (0.2 m) above the
driveway.
BENCH MARK STAMPING: 7624 G 1979
MONUMENTATION: Survey Disk VM#: 508
AGENCY: PID:
SETTING CLASSIFICATION: Concrete Step (Maury Hall)
The bench mark is set flush in the west corner of a concrete step at Maury Hall,
56.8 feet (17.3 m) SW of the flagpole at Watermans Hall, 50.6 feet (15.4 m) east
of the NW corner of the building, 29.6 feet (9.0 m) west of the NE corner of the
building, and about 0.5 foot (0.2 m) above the ground.
BENCH MARK STAMPING: 7624 K 1980
MONUMENTATION: Survey Disk VM#: 509
AGENCY: PID:
SETTING CLASSIFICATION: Galvanized Steel Rod
The bench mark is located in the median between State Road 1208 and State Road
1203, 63.9 feet (19.5 m) SW of VEPCO brace pole #80630, 29.3 feet (8.9 m) SSE of
the centerline of State Road 1208, 20.6 feet (6.3 m) SSE of the centerline of
State Road 1203, and 3.1 feet (0.9 m) SSW of a fire hydrant. The bench mark is
0.2 foot (0.1 m) below the ground, crimped to the galvanized steel rod driven 48
feet (15 m) to refusal, and encased in a 4-inch PVC pipe and concrete kickblock.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 4 of 6
PUBLICATION DATE: 04/28/1988
Station ID: 8637624 SUPERCEDED DATE: 04/21/2003
Name: GLOUCESTER POINT, YORK RIVER
VIRGINIA
NOAA Chart: 12241 Latitude: 37° 14.8' N
USGS Quad: POQUOSON WEST Longitude: 76° 30.0' W
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: G 298 RESET 1981
MONUMENTATION: Survey Disk VM#: 510
AGENCY: PID#: GV3523
SETTING CLASSIFICATION: Concrete Monument
The bench mark is set flush in the top of a concrete monument at Gloucester
Beach in the vicinity of a 12-foot (4 m) square cinder block building housing a
water pump, 102.4 feet (31.2 m) south of the SW corner of the 5th bent from the
north end of the bridge over York River,, 101.5 feet (30.9 m) NW of the
centerline of State Road 1208, 76 feet (23 m) SE of the 6th bent from the north
end of the bridge, and 1.8 feet (0.5 m) NE of the security fence around cinder
block building.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 5 of 6
PUBLICATION DATE: 04/28/1988
Station ID: 8637624 SUPERCEDED DATE: 04/21/2003
Name: GLOUCESTER POINT, YORK RIVER
VIRGINIA
NOAA Chart: 12241 Latitude: 37° 14.8' N
USGS Quad: POQUOSON WEST Longitude: 76° 30.0' W
T I D A L D A T U M S
Tidal datums at GLOUCESTER POINT, YORK RIVER based on:
LENGTH OF SERIES: 14 YEARS
TIME PERIOD: 1971-1984
TIDAL EPOCH: 1960-1978
CONTROL TIDE STATION: 8638610 HAMPTON ROADS
Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in FEET:
HIGHEST OBSERVED WATER LEVEL (03/07/1962) = 6.60
MEAN HIGHER HIGH WATER MHHW = 2.73
MEAN HIGH WATER MHW = 2.58
MEAN TIDE LEVEL MTL = 1.38
* NATIONAL GEODETIC VERTICAL DATUM NGVD29 = 1.16
MEAN LOW WATER MLW = 0.17
MEAN LOWER LOW WATER MLLW = 0.00
LOWEST OBSERVED WATER LEVEL (01/31/1966) = -2.80
* NGVD reference based on adjustment of 1972 and NOS levels of 1984.
North American Vertical Datum (NAVD88)
Bench Mark Elevation Information In FEET above:
Stamping or Designation MLLW MHW
7624 F 1979 11.58 9.00
NO 7 1950 6.70 4.12
NO 4 1918 33.70 31.12
NO 9 1959 30.91 28.33
D 457 1971 14.50 11.92
NO 8 1950 RESET 1973 12.29 9.71
7624 G 1979 33.19 30.61
7624 K 1980 35.33 32.75
G 298 RESET 1981 5.99 3.41
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 6 of 6
PUBLICATION DATE: 04/28/1988
Station ID: 8637624 SUPERCEDED DATE: 04/21/2003
Name: GLOUCESTER POINT, YORK RIVER
VIRGINIA
NOAA Chart: 12241 Latitude: 37° 14.8' N
USGS Quad: POQUOSON WEST Longitude: 76° 30.0' 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.