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Bench Mark Sheet for 8630249, CHINCOTEAGUE, USCG STATION 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Superseded Epoch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Small blue map location marker Unpublished bench mark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  5

                                                                                
Station ID: 8630249                         PUBLICATION DATE:  04/30/2003
Name:       CHINCOTEAGUE, USCG STATION                        
            VA
NOAA Chart: 12211                           Latitude:   37° 55.9' N (  37.93170)
USGS Quad:   CHINCOTEAGUE WEST              Longitude:  75° 23.0' W ( -75.38330)


To reach the tidal bench marks from the junction of State Highway 175 and Main
Street in Chincoteague, proceed 0.45 km (0.3 mi) SW along Main Street, to the
U.S. Coast Guard Base. The tide station was located at the northern edge of the
U.S. Coast Guard south wharf at Chincoteague.


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


                 PRIMARY BENCH MARK STAMPING:  NO 2 1962
                         DESIGNATION:          863 0249 TIDAL 2

MONUMENTATION:           Tidal Station disk                    VM#:         3253
AGENCY:                  US Coast and Geodetic Survey
                         (USC&GS)                              IDB PID#:  FW0136
SETTING CLASSIFICATION:  flagpole base                         OPUS PID:        
LATITUDE:   37° 55.9' N (  37.93170)          LONGITUDE:  75° 22.9' W ( -75.38170)


The primary bench mark is a disk set flush in the base of a flagepole, 61 m (200
ft) west of the centerline of Main Street, 11.58 m (38.0 ft) south of the north
boundary (an east-west fence) of the Coast Guard Station.



                         BENCH MARK STAMPING:  NO 3 1962
                         DESIGNATION:          863 0249 TIDAL 3

MONUMENTATION:           Tidal Station disk                    VM#:         3254
AGENCY:                  US Coast and Geodetic Survey
                         (USC&GS)                              IDB PID#:  FW0135
SETTING CLASSIFICATION:  Concrete porch                        OPUS PID:        
LATITUDE:   37° 55.8' N (  37.93000)          LONGITUDE:  75° 22.9' W ( -75.38170)


The bench mark is a disk located on the SW corner of the concrete porch of
Conant Brothers Hardware Store, and 8.23 m (27.0 ft) west of the centerline of
Main Street.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  2 of  5

                                                                                
Station ID: 8630249                         PUBLICATION DATE:  04/30/2003
Name:       CHINCOTEAGUE, USCG STATION                        
            VA
NOAA Chart: 12211                           Latitude:   37° 55.9' N (  37.93170)
USGS Quad:   CHINCOTEAGUE WEST              Longitude:  75° 23.0' W ( -75.38330)


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


                         BENCH MARK STAMPING:  TIDAL BM NO 4 1976
                         DESIGNATION:          863 0249 TIDAL 4 USE

MONUMENTATION:           Tidal Station disk                    VM#:         3256
AGENCY:                  US Army Corp of Engineers (USE)       IDB PID#:  FW0613
SETTING CLASSIFICATION:  Concrete post                         OPUS PID:        
LATITUDE:   37° 55.8' N (  37.93000)          LONGITUDE:  75° 22.9' W ( -75.38170)


The bench mark is a disk set in a concrete post, 11.43 m (37.5 ft) NW of the
centerline of Main Street, 9.60 m (31.5 ft) SE of telephone pole Number NO 1 AH,
3.14 m (10.3 ft) SW of the centerline of an exit driveway, and 0.06 m (0.2 ft)
below ground.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  3 of  5

                                                                                
Station ID: 8630249                         PUBLICATION DATE:  04/30/2003
Name:       CHINCOTEAGUE, USCG STATION                        
            VA
NOAA Chart: 12211                           Latitude:   37° 55.9' N (  37.93170)
USGS Quad:   CHINCOTEAGUE WEST              Longitude:  75° 23.0' W ( -75.38330)


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


                         BENCH MARK STAMPING:  T 421 1963
                         DESIGNATION:          T 421

MONUMENTATION:           Bench Mark disk                       VM#:         3257
AGENCY:                  US Coast and Geodetic Survey
                         (USC&GS)                              IDB PID#:  FW0139
SETTING CLASSIFICATION:  Concrete post                         OPUS PID:        
LATITUDE:   37° 55.4' N (  37.92330)          LONGITUDE:  75° 23.4' W ( -75.39000)


The bench mark is a disk set in a concrete post from the junction of State
Highway 175 and Main Street at Chincoteague, 20.57 m (67.5 ft) WNW and across
the street from the NW corner of a pink, one-story, block house, 7.93 m (26 ft)
west of the centerline of Main Street, 1.68 m (5.5 ft) NNE of power pole No. 34
H-6MX, and 0.06 m (0.2 ft) above ground level.



                         BENCH MARK STAMPING:  0249 A 1982
                         DESIGNATION:          863 0249 A

MONUMENTATION:           Tidal Station disk                    VM#:         3258
AGENCY:                  US Army Corp of Engineers (USE)       IDB PID#:        
SETTING CLASSIFICATION:  Concrete sea wall                     OPUS PID#: BBDL16
LATITUDE:   37° 55.0' N (  37.91670)          LONGITUDE:  75° 23.0' W ( -75.38330)


The bench mark is a disk set in the concrete seawall at the U.S. Coast Guard
Base, next to the boat ramp. 0.60 m (1.97 ft) NW of the SE corner of the
seawall, 0.48 m (1.59 ft) west of the east edge of the seawall, and 0.39 m (1.29
ft) SE of the inside corner of the seawall

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  4 of  5

                                                                                
Station ID: 8630249                         PUBLICATION DATE:  04/30/2003
Name:       CHINCOTEAGUE, USCG STATION                        
            VA
NOAA Chart: 12211                           Latitude:   37° 55.9' N (  37.93170)
USGS Quad:   CHINCOTEAGUE WEST              Longitude:  75° 23.0' W ( -75.38330)


                            T I D A L   D A T U M S 


Tidal datums at CHINCOTEAGUE, USCG STATION based on:

     LENGTH OF SERIES:      12 MONTHS
     TIME PERIOD:           February 1977 - January 1978
     TIDAL EPOCH:           1983-2001
     CONTROL TIDE STATION:  8638863 CHESAPEAKE BAY BRIDGE TUNNEL


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

     HIGHEST OBSERVED WATER LEVEL (10/14/1977)         =  1.136
     MEAN HIGHER HIGH WATER                     MHHW   =  0.561
     MEAN HIGH WATER                            MHW    =  0.511
     North American Vertical Datum              NAVD88 =  0.322
     MEAN TIDE LEVEL                            MTL    =  0.270
     MEAN SEA LEVEL                             MSL    =  0.269
     MEAN LOW WATER                             MLW    =  0.028
     MEAN LOWER LOW WATER                       MLLW   =  0.000
     LOWEST  OBSERVED WATER LEVEL (01/11/1978)         = -0.702

North American Vertical Datum (NAVD88)

Bench Mark Elevation Information                In METERS above:

     Stamping or Designation                    MLLW        MHW

     NO 2 1962                                   1.353    0.842
     NO 3 1962                                   1.529    1.018
     TIDAL BM NO 4 1976                          1.257    0.746
     T 421 1963                                  1.097    0.586
     0249 A 1982                                 1.035    0.524


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

                                                                                
Station ID: 8630249                         PUBLICATION DATE:  04/30/2003
Name:       CHINCOTEAGUE, USCG STATION                        
            VA
NOAA Chart: 12211                           Latitude:   37° 55.9' N (  37.93170)
USGS Quad:   CHINCOTEAGUE WEST              Longitude:  75° 23.0' W ( -75.38330)


                             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 8630249 CHINCOTEAGUE, USCG STATION, VA

Revised: 08/08/2018
NOAA / National Ocean Service
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