U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Datums Page Page 1 of 10
Station ID: 8636580 PUBLICATION DATE: 10/13/2020
Name: WINDMILL POINT, RAPPAHANNOCK RIVER
VA
NOAA Chart: 12235 Latitude: 37° 37.0' N ( 37.61611)
USGS Quad: DELTAVILLE Longitude: 76° 17.4' W ( -76.29000)
To reach the tidal bench marks from the town of Whitestone, Virginia, in white
stone from intersection of 3 (Rappahannock Drive) and Chesapeake Drive (VA 695)
go 12.1 km (7.5 mi) east (left) on Chesapeake Drive, go east (left) on
Windjammer Ln for 0.8 km (0.5 mi) located at 648 Windjammer Ln, at the dead end
of road.
T I D A L B E N C H M A R K S
PRIMARY BENCH MARK STAMPING: 6580 E 2011
DESIGNATION: 863 6580 E
MONUMENTATION: Flange-encased Rod VM#: 20258
AGENCY: NOS IDB PID:
SETTING CLASSIFICATION: Deep rod OPUS PID#: BBDN60
LATITUDE: 37° 36.9' N ( 37.61522) LONGITUDE: 76° 17.3' W ( -76.28781)
The bench mark is a flange-encased rod set 34.70 m (113.8 ft) west of condos at
121 building at the NW corner, 24.60 m (80.7 ft) east of the NE corner for the
condo, 14.04 m (46.1 ft) south of the SW corner of a wood sided building for
condo's water treatment, and 0.49 m (1.6 ft) north of a witness post, set flush
with the ground next to a sand barer fence that runs east and west between the
condos. The datum point being the top of a stainless steel rod driven 26.8 m
(87.9 ft) to refusal, and encased in a 5-inch PVC pipe in concrete with a NOS
logo cap set flush with the ground.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 2 of 10
Station ID: 8636580 PUBLICATION DATE: 10/13/2020
Name: WINDMILL POINT, RAPPAHANNOCK RIVER
VA
NOAA Chart: 12235 Latitude: 37° 37.0' N ( 37.61611)
USGS Quad: DELTAVILLE Longitude: 76° 17.4' W ( -76.29000)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 6580 B 1982
DESIGNATION: 863 6580 B
MONUMENTATION: Tidal Station disk VM#: 11256
AGENCY: National Ocean Survey (NOS) IDB PID:
SETTING CLASSIFICATION: Unspecified deep rod OPUS PID:
LATITUDE: 37° 37.0' N ( 37.61656) LONGITUDE: 76° 17.6' W ( -76.29342)
The bench mark is a disk located in The Landing townhouse development at the
Windmill Point Marina, 36.6 m (120 ft) NE of the northeasternmost corner of a
row of wood siding townhouses, 21.24 m (69.7 ft) NNW of the centerline of County
Route 695, and 6.71 m (22.0 ft) NW of telephone pole numbered XJ41. The bench
mark is 0.09 m (0.3 ft) below ground, crimped to an unspecified rod driven 16.5
m (54 ft) to refusal, and encased in a PVC pipe extending 0.09 m (0.3 ft) above
ground.
BENCH MARK STAMPING: 6580 G 2011
DESIGNATION: 863 6580 G
MONUMENTATION: Flange-encased Rod VM#: 20260
AGENCY: NOS IDB PID:
SETTING CLASSIFICATION: Stainless steel rod OPUS PID:
LATITUDE: 37° 37.0' N ( 37.61719) LONGITUDE: 76° 17.4' W ( -76.28978)
The bench mark is a flange-encase rod located 8.00 m (26.2 ft) north of the
center line of Windjammer Ln, 7.00 m (23.0 ft) NW of the center line of two
steel gates leading to a retention pond and sewage pumping station on the north
side of Windjammer Ln, and 6.30 m (20.7 ft) south from a power pole F141 on the
north side of Windjammer Ln. The datum point being the top of a stainless steel
rod driven to refusal, and encased in a 5 inch (13 cm) PVC pipe in concrete with
a NOS logo cap set flush with the ground.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 3 of 10
Station ID: 8636580 PUBLICATION DATE: 10/13/2020
Name: WINDMILL POINT, RAPPAHANNOCK RIVER
VA
NOAA Chart: 12235 Latitude: 37° 37.0' N ( 37.61611)
USGS Quad: DELTAVILLE Longitude: 76° 17.4' W ( -76.29000)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 6580 J 2011
DESIGNATION: 863 6580 J
MONUMENTATION: Flange-encased Rod VM#: 20262
AGENCY: NOS IDB PID:
SETTING CLASSIFICATION: Stainless steel rod OPUS PID#: BBDN98
LATITUDE: 37° 37.1' N ( 37.61767) LONGITUDE: 76° 17.5' W ( -76.29247)
The bench mark is a flange-encased rod located on the south side of Windjammer
Ln at the Windmill Point Marina, 31.47 m (103.2 ft) east of the NE corner of
6809 Landing Townhouse development residence, 27.36 m (89.8 ft) east of a power
pole 631F-258 which is located on the east side of VA-695 (Chesapeake Ln), 13.50
m (44.3 ft) north of the center line of graveled section of Windjammer Ln, 12.14
m (39.8 ft) WSW of a phone pedestal 21-95) located on the west side of
Chesapeake Ln and south of graveled section of Windjammer Ln leading to a water
pumping station, and 3.98 m (13.1 ft) SE of a NOAA witness post that is next to
a power pole 631F252. The datum point being the top of a stainless steel rod
driven to refusal, and encased in a 5 inch (13 cm) PVC pipe 0.12 m (0.4 ft)
below ground.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 4 of 10
Station ID: 8636580 PUBLICATION DATE: 10/13/2020
Name: WINDMILL POINT, RAPPAHANNOCK RIVER
VA
NOAA Chart: 12235 Latitude: 37° 37.0' N ( 37.61611)
USGS Quad: DELTAVILLE Longitude: 76° 17.4' W ( -76.29000)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: X 459 1971
DESIGNATION: X 459
MONUMENTATION: Bench Mark disk VM#: 20263
AGENCY: Coast and Geodetic Survey IDB PID#: GV0083
SETTING CLASSIFICATION: Copper coated rod OPUS PID:
LATITUDE: 37° 38.0' N ( 37.63297) LONGITUDE: 76° 18.5' W ( -76.30867)
The bench mark is a disk located near the intersection of Camp Rd and Windmill
Point Rd, 7.60 m (25 ft) NW of the center line of the road, 0.30 m (1.0 ft) SW
of power pole number 39, 0.21 cm (0 inch) NE of a metal witness post, level with
the road and on top of a 4-foot section of copper coated rod that is attached to
a metal base plate, 8 cm (3 inches) below the surface of the ground and is
protected by a 4-inch (10 cm) Orangeburg pipe that is level with the ground.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 5 of 10
Station ID: 8636580 PUBLICATION DATE: 10/13/2020
Name: WINDMILL POINT, RAPPAHANNOCK RIVER
VA
NOAA Chart: 12235 Latitude: 37° 37.0' N ( 37.61611)
USGS Quad: DELTAVILLE Longitude: 76° 17.4' W ( -76.29000)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: W 459 1971
DESIGNATION: W 459
MONUMENTATION: Bench Mark disk VM#: 20264
AGENCY: USC&GS IDB PID#: GV0084
SETTING CLASSIFICATION: Copper coated rod OPUS PID:
LATITUDE: 37° 37.9' N ( 37.63131) LONGITUDE: 76° 17.5' W ( -76.29228)
The bench mark is a disk located near the entrance to Bay View, 11.00m (36.1 ft)
east of the centerline of the road, 6.10m (20.0 ft) south of the center line of
the driveway to Bay View, and 2.40m (7.9 ft) SSW of the more southerly brace
pole for the Bay View gate.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 6 of 10
Station ID: 8636580 PUBLICATION DATE: 10/13/2020
Name: WINDMILL POINT, RAPPAHANNOCK RIVER
VA
NOAA Chart: 12235 Latitude: 37° 37.0' N ( 37.61611)
USGS Quad: DELTAVILLE Longitude: 76° 17.4' W ( -76.29000)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: H 272 1942
DESIGNATION: H 272
MONUMENTATION: Bench Mark disk VM#: 20265
AGENCY: USC&GS IDB PID#: GV0082
SETTING CLASSIFICATION: Concrete monument OPUS PID:
LATITUDE: 37° 37.8' N ( 37.62922) LONGITUDE: 76° 18.8' W ( -76.31303)
The bench mark is a disk located on the NE side of the Asbury Church property,
13.40m (44.0 ft) NW of the centerline of the road, 9.80m (32.2 ft) NE of the
East corner of the church, 3.00m (9.8 ft) NW of power pole number 48420. The
bench mark is about level with the county road and set in the top of a concrete
post which projects 12.70 cm (5 in).
BENCH MARK STAMPING: 6580 L 2015
DESIGNATION: 863 6580 L
MONUMENTATION: Tidal Station disk VM#: 21636
AGENCY: NOS IDB PID:
SETTING CLASSIFICATION: Foundation of medium sized build OPUS PID:
LATITUDE: 37° 37.0' N ( 37.61608) LONGITUDE: 76° 17.5' W ( -76.29214)
The bench mark is set flush in the top of a massive concrete pad on the NW
foundation of the Windmill Point Marina main building, 45.7 m (149.9 ft) east of
the fire hydrant in the westernmost gravel parking lot within the facility, 14.6
m (47.9 ft) SW of the second green lamp post from the western edge along the
southern marina bulkhead, and 4.3 m (14.1 ft) west of the double doors on the NW
side of the main marina building.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 7 of 10
Station ID: 8636580 PUBLICATION DATE: 10/13/2020
Name: WINDMILL POINT, RAPPAHANNOCK RIVER
VA
NOAA Chart: 12235 Latitude: 37° 37.0' N ( 37.61611)
USGS Quad: DELTAVILLE Longitude: 76° 17.4' W ( -76.29000)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 6580 M 2016
DESIGNATION: 863 6580 M
MONUMENTATION: Bench Mark disk VM#: 21917
AGENCY: NOS IDB PID:
SETTING CLASSIFICATION: Concrete pad OPUS PID:
LATITUDE: 37° 37.0' N ( 37.61636) LONGITUDE: 76° 17.5' W ( -76.29142)
The bench mark is a brass disc set atop the north corner of a concrete pad
holding power distribution boxes on the north side of the basin north of the
clubhouse, 12.4 m (40.7 ft) north of the landing to the ramp of a floating dock
located along the bulkhead, 7.6 m (24.9 ft) NNE of the SSW face of the bulkhead,
and 3.45 m (11.3 ft) south of the east corner of a concrete pad holding
electrical transformers.
BENCH MARK STAMPING: 6580 N 2016
DESIGNATION: 863 6580 N
MONUMENTATION: Bench Mark disk VM#: 21972
AGENCY: NOS IDB PID:
SETTING CLASSIFICATION: Concrete pad OPUS PID:
LATITUDE: 37° 36.9' N ( 37.61564) LONGITUDE: 76° 17.5' W ( -76.29139)
The bench mark is a brass disc set in the SE corner of a concrete pad holding
power distribution boxes east of the clubhouse located 17.6 m (57.7 ft) SSW of
the SE corner of a concrete pad holding electrical transformers, 6.4 m (21.0 ft)
SE of the east corner of the shallow end of the pool, and 1.1 m (3.6 ft) NW of
the curve in the retaining wall east of the power distribution boxes.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 8 of 10
Station ID: 8636580 PUBLICATION DATE: 10/13/2020
Name: WINDMILL POINT, RAPPAHANNOCK RIVER
VA
NOAA Chart: 12235 Latitude: 37° 37.0' N ( 37.61611)
USGS Quad: DELTAVILLE Longitude: 76° 17.4' W ( -76.29000)
T I D A L D A T U M S
Tidal datums at WINDMILL POINT, RAPPAHANNOCK RIVER based on:
LENGTH OF SERIES: 7 YEARS
TIME PERIOD: June 2012 - May 2019
TIDAL EPOCH: 1983-2001
CONTROL TIDE STATION: 8635750 LEWISETTA, POTOMAC RIVER
Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in METERS:
HIGHEST OBSERVED WATER LEVEL (09/01/2006) = 1.578
MEAN HIGHER HIGH WATER MHHW = 0.423
MEAN HIGH WATER MHW = 0.383
North American Vertical Datum NAVD88 = 0.358
MEAN SEA LEVEL MSL = 0.212
MEAN TIDE LEVEL MTL = 0.206
MEAN LOW WATER MLW = 0.030
MEAN LOWER LOW WATER MLLW = 0.000
LOWEST OBSERVED WATER LEVEL (01/07/2018) = -0.621
North American Vertical Datum (NAVD88)
Bench Mark Elevation Information In METERS above:
Stamping or Designation MLLW MHW
6580 E 2011 1.514 1.131
6580 B 1982 1.167 0.784
6580 G 2011 1.293 0.910
6580 J 2011 1.384 1.001
X 459 1971 0.930 0.547
W 459 1971 1.376 0.993
H 272 1942 1.424 1.041
6580 L 2015 1.796 1.413
6580 M 2016 1.877 1.494
6580 N 2016 2.409 2.026
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 9 of 10
Station ID: 8636580 PUBLICATION DATE: 10/13/2020
Name: WINDMILL POINT, RAPPAHANNOCK RIVER
VA
NOAA Chart: 12235 Latitude: 37° 37.0' N ( 37.61611)
USGS Quad: DELTAVILLE Longitude: 76° 17.4' W ( -76.29000)
Foot Notes:
Bench marks H 272 1942, W 459 1971, and X 459 1971 are based on one differential
leveling connection occurring during this datum series and do not meet the
quality control standards of the NOS. Therefore, caution should be used when
deriving elevations for these marks.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 10 of 10
Station ID: 8636580 PUBLICATION DATE: 10/13/2020
Name: WINDMILL POINT, RAPPAHANNOCK RIVER
VA
NOAA Chart: 12235 Latitude: 37° 37.0' N ( 37.61611)
USGS Quad: DELTAVILLE Longitude: 76° 17.4' W ( -76.29000)
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.