U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Datums Page Page 1 of 6
Station ID: 8631591 PUBLICATION DATE: 03/09/2004
Name: OYSTER HARBOR
VA
NOAA Chart: 12221 Latitude: 37° 17.3' N ( 37.28830)
USGS Quad: CHERITON Longitude: 75° 55.5' W ( -75.92500)
To reach the tidal bench marks from the post office at Cherton, Virginia,
proceed south on US Route 13 for 32.2 km (20 mi) to State Road T639, hence east
along T639 for 3.7 km (2.3 mi) to State Road 1802, hence north along 1802 for
1.1 km (0.7 mi) to the end at Oyster Harbor. The tide gage and staff were
positioned on the eastern side of the wooden T pier.
T I D A L B E N C H M A R K S
PRIMARY BENCH MARK STAMPING: 1591 A 1980
DESIGNATION: 863 1591 A TIDAL
MONUMENTATION: Tidal Station disk VM#: 3350
AGENCY: National Ocean Survey (NOS) IDB PID#:
SETTING CLASSIFICATION: Stainless steel rod OPUS PID:
LATITUDE: 37° 17.3' N ( 37.28830) LONGITUDE: 75° 55.5' W ( -75.92500)
The primary bench mark is a disk crimped to the top of a stainless steel rod,
located north of the east end of Route 1802, 0.82 m (2.72 ft) south of two
wooden posts (6-inch x 6-inch and 4-inch x 4-inch) bolted together and set
vertically in the ground and 0.34 m (1.14 ft) NE of a metal witness post. The
disk is crimped to the top of a stainless steel rod driven 19.51 m (64.0 ft) 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 2 of 6
Station ID: 8631591 PUBLICATION DATE: 03/09/2004
Name: OYSTER HARBOR
VA
NOAA Chart: 12221 Latitude: 37° 17.3' N ( 37.28830)
USGS Quad: CHERITON Longitude: 75° 55.5' W ( -75.92500)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 1591 B 1980
DESIGNATION: 863 1591 B TIDAL
MONUMENTATION: Tidal Station disk VM#: 3351
AGENCY: National Ocean Survey (NOS) IDB PID#:
SETTING CLASSIFICATION: Stainless steel rod OPUS PID:
LATITUDE: 37° 17.3' N ( 37.28830) LONGITUDE: 75° 55.5' W ( -75.92500)
The bench mark is a disk crimped to the top of a stainless steel rod, located
47.18 m (154.85 ft) south of Bench Mark 1591 A 1980, and 0.66 m (2.17 ft) east
of D.P.& L.C. power pole 102B. The disk is crimped to the top of a stainless
steel rod driven 17 m (56 ft) to refusal and encased in a 4 inch PVC pipe and
concrete kickblock.
BENCH MARK STAMPING: 1591 C 1980
DESIGNATION: 863 1591 C TIDAL
MONUMENTATION: Tidal Station disk VM#: 3352
AGENCY: National Ocean Survey (NOS) IDB PID#:
SETTING CLASSIFICATION: Stainless steel rod OPUS PID:
LATITUDE: 37° 17.3' N ( 37.28830) LONGITUDE: 75° 55.5' W ( -75.92500)
The bench mark is a disk crimped to the top of a stainless steel rod, located SW
of Bench Mark 1591 B 1980, SW of a two story frame house and 0.82 m (2.74 ft)
south of D.P.& L.C. power pole 102K. The disk is crimped to the top of a
stainless steel rod driven 17 m (56 ft) 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 3 of 6
Station ID: 8631591 PUBLICATION DATE: 03/09/2004
Name: OYSTER HARBOR
VA
NOAA Chart: 12221 Latitude: 37° 17.3' N ( 37.28830)
USGS Quad: CHERITON Longitude: 75° 55.5' W ( -75.92500)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 1591 D 1980
DESIGNATION: 863 1591 D TIDAL
MONUMENTATION: Tidal Station disk VM#: 3353
AGENCY: National Ocean Survey (NOS) IDB PID#:
SETTING CLASSIFICATION: Stainless steel rod OPUS PID:
LATITUDE: 37° 17.3' N ( 37.28830) LONGITUDE: 75° 55.5' W ( -75.92500)
The bench mark is a disk crimped to the top of a stainless steel rod, located
west of Bench Mark 1591 C 1980, northeast of the intersection of Route 1802 and
a dirt driveway leading to a two story frame house, 1.37 m (4.5 ft) SW of a 4
inch diameter hackberry tree, 0.94 m (3.1 ft) north of a 6 inch diameter wild
cherry tree and 0.3 m (1 ft) SE of a metal witness post. The disk is crimped to
the top of a stainless steel rod driven 14.63 m (48.0 ft) to refusal and encased
in a 4 inch PVC and concrete kickblock.
BENCH MARK STAMPING: 1591 E 1980
DESIGNATION: 863 1591 E TIDAL
MONUMENTATION: Tidal Station disk VM#: 3354
AGENCY: National Ocean Survey (NOS) IDB PID#:
SETTING CLASSIFICATION: Stainless steel rod OPUS PID:
LATITUDE: 37° 17.3' N ( 37.28830) LONGITUDE: 75° 55.5' W ( -75.92500)
The bench mark is a disk crimped to the top of a stainless steel rod, located SW
of Bench Mark 1591 E 1980, east of Route 1802, 0.58 m (1.9 ft) east of D.P.&
L.C. power pole 102F, and 0.36 m (1.17 ft) west of a metal witness post. The
disk is crimped to the top of a stainless steel rod driven 12.19 m (40.0 ft) to
refusal and encased in a PVC and concrete kickblock.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 4 of 6
Station ID: 8631591 PUBLICATION DATE: 03/09/2004
Name: OYSTER HARBOR
VA
NOAA Chart: 12221 Latitude: 37° 17.3' N ( 37.28830)
USGS Quad: CHERITON Longitude: 75° 55.5' W ( -75.92500)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 1591 F 1980
DESIGNATION: 863 1591 F TIDAL
MONUMENTATION: Tidal Station disk VM#: 3355
AGENCY: National Ocean Survey (NOS) IDB PID#:
SETTING CLASSIFICATION: Stainless steel rod OPUS PID:
LATITUDE: 37° 17.3' N ( 37.28830) LONGITUDE: 75° 55.5' W ( -75.92500)
The bench mark is a disk located north of Bench Mark 1591 A 1980, 4.33 m (14.2
ft) south and west of the westernedge of Route 1802, 2.29 m (7.5 ft) east of a
0.61 m (2.0 ft) diameter maple tree, and 0.36 m (1.15 ft) NE of a metal witness
post.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 5 of 6
Station ID: 8631591 PUBLICATION DATE: 03/09/2004
Name: OYSTER HARBOR
VA
NOAA Chart: 12221 Latitude: 37° 17.3' N ( 37.28830)
USGS Quad: CHERITON Longitude: 75° 55.5' W ( -75.92500)
T I D A L D A T U M S
Tidal datums at OYSTER HARBOR based on:
LENGTH OF SERIES: 2 MONTHS
TIME PERIOD: March 1981 - April 1981
TIDAL EPOCH: 1983-2001
CONTROL TIDE STATION: 8631542 SAND SHOAL INLET, COBB ISLAND
Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in METERS:
MEAN HIGHER HIGH WATER MHHW = 1.536
MEAN HIGH WATER MHW = 1.434
MEAN SEA LEVEL MSL = 0.752
MEAN TIDE LEVEL MTL = 0.745
MEAN LOW WATER MLW = 0.056
MEAN LOWER LOW WATER MLLW = 0.000
North American Vertical Datum (NAVD88)
Bench Mark Elevation Information In METERS above:
Stamping or Designation MLLW MHW
1591 A 1980 2.761 1.327
1591 B 1980 2.534 1.100
1591 C 1980 2.773 1.339
1591 D 1980 7.515 6.081
1591 E 1980 6.648 5.214
1591 F 1980 3.781 2.347
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 6 of 6
Station ID: 8631591 PUBLICATION DATE: 03/09/2004
Name: OYSTER HARBOR
VA
NOAA Chart: 12221 Latitude: 37° 17.3' N ( 37.28830)
USGS Quad: CHERITON Longitude: 75° 55.5' W ( -75.92500)
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.