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Bench Mark Sheet for 8636580, Windmill Point VA

Superseded Epoch

Large map location marker Station Location
Small red map location marker Published bench mark
Small blue map location marker Unpublished bench mark

Bench mark positions only appear on the map if their coordinates in the CO-OPS database are at the precision of degrees/minutes/seconds/and tenths of seconds. If the coordinates are less precise, the mark will not appear.

Printable version

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
Datums Page                                                        Page  1 of  6

                                                                                
Station ID: 8636580                         PUBLICATION DATE:  04/21/2003
Name:       WINDMILL POINT                                    
            VA
NOAA Chart: 12235                           Latitude:   37° 36.9' N (  37.61500)
USGS Quad:  DELTAVILLE                      Longitude:  76° 17.4' W ( -76.29000)


To reach the tidal bench marks from the town of Whitestone, Virginia, at the
junction of State Highways 3 and 200, proceed SE on County Route 695 for 11.7 km
(7.3 mi) to the dead end.  The bench marks are in the area between the Exxon
Station and the pier.  The tide gage and staff were located on the end of the
pier.


                         T I D A L   B E N C H   M A R K S


                 PRIMARY BENCH MARK STAMPING:  NO 2 1970

MONUMENTATION:           Tidal Station disk                    VM#:        11254
AGENCY:                  National Ocean Survey (NOS)           IDB PID#:  GV0088
SETTING CLASSIFICATION:  Concrete foundation                   OPUS PID:        
LATITUDE:   37° 37.0' N (  37.61670)          LONGITUDE:  76° 17.4' W ( -76.29000)


The primary bench mark is a disk set in the center of the NE footing of three
footings for I-Beams that previously supported a large EXXON sign, 0.46 m (1.5
ft) east of an I-Beam, and 0.15 m (0.5 ft) above ground.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  2 of  6

                                                                                
Station ID: 8636580                         PUBLICATION DATE:  04/21/2003
Name:       WINDMILL POINT                                    
            VA
NOAA Chart: 12235                           Latitude:   37° 36.9' N (  37.61500)
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 A 1982
                         DESIGNATION:          WINDMILL POINT BM 6580 A

MONUMENTATION:           Tidal Station disk                    VM#:        11255
AGENCY:                  National Ocean Survey (NOS)           IDB PID#:  GV6186
SETTING CLASSIFICATION:  Unspecified deep rod                  OPUS PID:        
LATITUDE:   37° 36.9' N (  37.61500)          LONGITUDE:  76° 17.6' W ( -76.29330)


The bench mark is a disk located at the SE end of Country Road 695 between a
pier and the end of the road, 52.7 m (173 ft) south of the southernmost corner
of a row of eight brick townhouses, 21.34 m (70.0 ft) ESE of the extended
centerline of County Road 695, 9.91 m (32.5 ft) NE of the easternmost corner of
the pier, and 0.06 m (0.2 ft) west of an orange witness post. The bench mark is
0.09 m (0.3 ft) below ground, crimped to an unspecified rod driven 15.2 m (50
ft) to refusal, and encased in a PVC pipe extending 0.12 m (0.4 ft)  above the
ground.



                         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 (  37.61639)          LONGITUDE:  76° 17.6' W ( -76.29350)


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.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  3 of  6

                                                                                
Station ID: 8636580                         PUBLICATION DATE:  04/21/2003
Name:       WINDMILL POINT                                    
            VA
NOAA Chart: 12235                           Latitude:   37° 36.9' N (  37.61500)
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 C 1982
                         DESIGNATION:          863 6580 C

MONUMENTATION:           Tidal Station disk                    VM#:        11257
AGENCY:                  National Ocean Survey (NOS)           IDB PID:         
SETTING CLASSIFICATION:  Unspecified deep rod                  OPUS PID:        
LATITUDE:   37° 37.0' N (  37.61670)          LONGITUDE:  76° 17.6' W ( -76.29330)


The bench mark is a disk located on the SE side of County Road 695 and on the
SSW side of the first entrance road to the Windmill Point Marine Resort, 37.80 m
(124.0 ft) NW of the centerline of the road leading to the Conference Center
Building, 31.33 m (102.8 ft) SSW of the SW corner of a brick townhouse, 19.23 m
(63.1 ft) SE of the centerline of County Road 695, 15.24 m (50.0 ft) SSW of the
centerline of the road leading to the resort, and 0.06 m (0.2 ft) NW of a
witness post.  The bench mark is 0.09 m (0.3 ft) below ground, crimped to the
top of an unspecified rod driven 14.0 m (46 ft) to refusal.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  4 of  6

                                                                                
Station ID: 8636580                         PUBLICATION DATE:  04/21/2003
Name:       WINDMILL POINT                                    
            VA
NOAA Chart: 12235                           Latitude:   37° 36.9' N (  37.61500)
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 D 1982
                         DESIGNATION:          863 6580 D

MONUMENTATION:           Tidal Station disk                    VM#:        11258
AGENCY:                  National Ocean Survey (NOS)           IDB PID:         
SETTING CLASSIFICATION:  Unspecified deep rod                  OPUS PID:        
LATITUDE:   37° 37.0' N (  37.61670)          LONGITUDE:  76° 17.5' W ( -76.29170)


The bench mark is a disk located NE of the parking lot for the resort motel, in
line with a 0.9 m (3 ft) maple tree, 53.77 m (176.4 ft) NNW of the center of the
entrance door to the motel lobby, 51.21 m (168.0 ft) SW of the westernmost
support of the large I-Beam foundation, 32.92 m (108.0 ft) NE of the centerline
of the drive that leads to the motel front entrance, 24.48 m (80.3 ft) SW of the
SW corner of a one story wood building, and 14.33 m (47.0 ft) SE of the
centerline of the road that leads to the docks. The bench mark is 0.09 m (0.3
ft) below ground, crimped to an unspecified rod driven 15.2 m (50 ft) to
refusal, and encased in a 4 inch PVC pipe.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  5 of  6

                                                                                
Station ID: 8636580                         PUBLICATION DATE:  04/21/2003
Name:       WINDMILL POINT                                    
            VA
NOAA Chart: 12235                           Latitude:   37° 36.9' N (  37.61500)
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 based on:

     LENGTH OF SERIES:      4 Years
     TIME PERIOD:           June 1994 - May 1998
     TIDAL EPOCH:           1983-2001
     CONTROL TIDE STATION:  8577330 SOLOMONS ISLAND, PATUXENT RIVER


Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in METERS:

     HIGHEST OBSERVED WATER LEVEL (02/05/1998)         =  1.242
     MEAN HIGHER HIGH WATER                     MHHW   =  0.424
     MEAN HIGH WATER                            MHW    =  0.384
     North American Vertical Datum              NAVD88 =  0.289
     MEAN SEA LEVEL                             MSL    =  0.214
     MEAN TIDE LEVEL                            MTL    =  0.207
     MEAN LOW WATER                             MLW    =  0.030
     MEAN LOWER LOW WATER                       MLLW   =  0.000
     LOWEST  OBSERVED WATER LEVEL (02/06/1995)         = -0.601

North American Vertical Datum (NAVD88)

Bench Mark Elevation Information                In METERS above:

     Stamping or Designation                    MLLW        MHW

     NO 2 1970                                   1.591    1.207
     6580 A 1982                                 1.821    1.437
     6580 B 1982                                 1.153    0.769
     6580 C 1982                                 0.992    0.608
     6580 D 1982                                 1.538    1.154


                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  6 of  6

                                                                                
Station ID: 8636580                         PUBLICATION DATE:  04/21/2003
Name:       WINDMILL POINT                                    
            VA
NOAA Chart: 12235                           Latitude:   37° 36.9' N (  37.61500)
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.

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Products available at 8636580 Windmill Point, VA

Revised: 10/15/2013
NOAA / National Ocean Service
Web site owner: Center for Operational Oceanographic Products and Services