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Bench Mark Sheet for 8513825, SMITH POINT BRIDGE, NARROW BAY NY

Superseded Epoch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Small blue map location marker Unpublished bench mark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  7

                                                                                
Station ID: 8513825                         PUBLICATION DATE:  05/31/2005
Name:       SMITH POINT BRIDGE, NARROW BAY                    
            NY
NOAA Chart: 12353                           Latitude:   40° 44.3' N (  40.73830)
USGS Quad:  PATTERSQUASH ISLAND             Longitude:  72° 52.1' W ( -72.86830)


To reach the tidal bench marks from the intersection of Sunrise Highway (State
Highway 27) and William Floyd Parkway (County Highway 46), proceed south on
William Floyd Parkway for 7.4 km (4.6 mi) to the north end of the higway bridge
over Narrow Bay.  The tidal bench marks are along William Floyd Parkway and at
Smith Point Park.  The tide gage and staff were on the north side of the NE
bridge fender.


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


                 PRIMARY BENCH MARK STAMPING:  3825 B 1989
                         DESIGNATION:          851 3825 B

MONUMENTATION:           Bench Mark disk                       VM#:         4855
AGENCY:                  US Coastal and Geodetic Survey
                         (USC&GS)                              IDB PID#:        
SETTING CLASSIFICATION:  Concrete sidewalk                     OPUS PID:        
LATITUDE:   40° 44.3' N (  40.73830)          LONGITUDE:  72° 52.1' W ( -72.86830)


The primary bench mark is a disk set flush in the concrete sidewalk over the NE
corner abutment of Smith Point Bridge, 6 m (20 ft) south of the northeasternmost
steel handrail post, 5.43 m (17.8 ft) east of the centeline of William Floyd
Parkway, and 0.24 m (0.8 ft) south of the SE corner of a square steel manhole
cover in the sidewalk.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  2 of  7

                                                                                
Station ID: 8513825                         PUBLICATION DATE:  05/31/2005
Name:       SMITH POINT BRIDGE, NARROW BAY                    
            NY
NOAA Chart: 12353                           Latitude:   40° 44.3' N (  40.73830)
USGS Quad:  PATTERSQUASH ISLAND             Longitude:  72° 52.1' W ( -72.86830)


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


                         BENCH MARK STAMPING:  H 378 1956
                         DESIGNATION:          851 3825 H 378

MONUMENTATION:           Bench Mark disk                       VM#:         4852
AGENCY:                  US Coastal and Geodetic Survey
                         (USC&GS)                              IDB PID#:  KU0235
SETTING CLASSIFICATION:  Concrete monument                     OPUS PID:        
LATITUDE:   40° 45.1' N (  40.75170)          LONGITUDE:  72° 52.3' W ( -72.87170)


The bench mark is a disk set in a concrete monument, 4.1 km (2.6 mi) south along
William Floyd Parkway from its intersection with State Highway 27, at the SW
corner of the intersection of William Floyd Parkway and West Minster Drive, 7 m
(23 ft) south of the center- line of West Minster Drive, 1.10 m (3.6 ft) south
of power pole #18, and 0.03 m (0.1 ft) above ground level.



                         BENCH MARK STAMPING:  END NO 1 1962
                         DESIGNATION:          851 3825 END TIDAL 1

MONUMENTATION:           Bench Mark disk                       VM#:         4853
AGENCY:                  US Coastal and Geodetic Survey
                         (USC&GS)                              IDB PID#:  AE4708
SETTING CLASSIFICATION:  Concrete sidwalk                      OPUS PID:        
LATITUDE:   40° 44.3' N (  40.73830)          LONGITUDE:  72° 52.1' W ( -72.86830)


The bench mark is a disk set flush in the concrete sidewalk at the SW end of the
Smith Point Bridge, 6.40 m (21.0 ft) SE of the SE corner of the southwestern
corner concrete block of the bridge, 5.67 m (18.6 ft) west of the centerline of
William Floyd Parkway, and 1.83 m (6.0 ft) east of a wooden railing.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  3 of  7

                                                                                
Station ID: 8513825                         PUBLICATION DATE:  05/31/2005
Name:       SMITH POINT BRIDGE, NARROW BAY                    
            NY
NOAA Chart: 12353                           Latitude:   40° 44.3' N (  40.73830)
USGS Quad:  PATTERSQUASH ISLAND             Longitude:  72° 52.1' W ( -72.86830)


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


                         BENCH MARK STAMPING:  3825 A 1989
                         DESIGNATION:          851 3825 A

MONUMENTATION:           Bench Mark disk                       VM#:         4854
AGENCY:                  US Coastal and Geodetic Survey
                         (USC&GS)                              IDB PID#:        
SETTING CLASSIFICATION:  Concrete base                         OPUS PID#: BBDB78
LATITUDE:   40° 44.3' N (  40.73830)          LONGITUDE:  72° 52.1' W ( -72.86830)


The bench mark is a disk set flush in the SW corner of the 2 m x 2 m (6 ft x 6
ft) concrete base of an antenna at the administration building of Smith Point
Bridge, 7.62 m (25.0 ft) SSW of the SE corner of the building, 4 m (15 ft) SSE
of the SW corner of the building, 4.69 m (15.4 ft) ENE of the east curb of the
southbound lane of the highway, and 0.15 m (0.5 ft) above ground level.



                         BENCH MARK STAMPING:  3825 C 1989
                         DESIGNATION:          851 3825 C

MONUMENTATION:           Bench Mark disk                       VM#:         4856
AGENCY:                  US Coastal and Geodetic Survey
                         (USC&GS)                              IDB PID#:        
SETTING CLASSIFICATION:  Stainless steel rod                   OPUS PID:        
LATITUDE:   40° 44.3' N (  40.73830)          LONGITUDE:  72° 52.1' W ( -72.86830)


The bench mark is a disk 76.05 m (249.5 ft) south of the SW corner of the
southwestern corner concrete block of Smith Point Bridge, 23.47 m (77.0 ft) west
of the centerline of William Floyd Parkway, and 1.31 m (4.3 ft) east of a 1 m (4
ft) high chain link fence and witness post.  The bench mark is 0.09 m (0.3 ft)
below ground level, crimped to a stainless steel rod driven 21 m (68 ft) to
substantial resistance, and encased in a 5-inch PVC pipe and concrete kickblock.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  4 of  7

                                                                                
Station ID: 8513825                         PUBLICATION DATE:  05/31/2005
Name:       SMITH POINT BRIDGE, NARROW BAY                    
            NY
NOAA Chart: 12353                           Latitude:   40° 44.3' N (  40.73830)
USGS Quad:  PATTERSQUASH ISLAND             Longitude:  72° 52.1' W ( -72.86830)


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


                         BENCH MARK STAMPING:  SMITH POINT SET 1989
                         DESIGNATION:          851 3825 SMITH POINT SET

MONUMENTATION:           Bench Mark disk                       VM#:         4857
AGENCY:                  US Coastal and Geodetic Survey
                         (USC&GS)                              IDB PID#:        
SETTING CLASSIFICATION:  Concrete sidewalk                     OPUS PID:        
LATITUDE:   40° 44.3' N (  40.73830)          LONGITUDE:  72° 52.1' W ( -72.86830)


The bench mark is a disk set flush in the concrete sidewalk over the easternmost
of two pedestrian underpasses at Smith Point Park, 5.79 m (19.0 ft) NW of the
centerline of the westbound lanes of the park, 0.98 m (3.2 ft) SE of the
concrete handrail, and 0.82 m (2.7 ft) NE of the SW edge of the sidewalk.



                         BENCH MARK STAMPING:  2 993
                         DESIGNATION:          851 3825 2 993

MONUMENTATION:           Bench Mark disk                       VM#:         4858
AGENCY:                  US Coastal and Geodetic Survey
                         (USC&GS)                              IDB PID#:        
SETTING CLASSIFICATION:  Concrete monument                     OPUS PID:        
LATITUDE:   40° 44.3' N (  40.73830)          LONGITUDE:  72° 52.1' W ( -72.86830)


The bench mark is a disk set in a concrete monument at the eastern turnaround at
Smith Point Park, 21.46 m (70.4 ft) SSE of the centerline of the westbound
lanes, 20.63 m (67.7 ft) SSW of the center of an hexagonal-shaped flower garden
ringed by railroad ties and posts, 6.55 m (21.5 ft) NNW of the centerline of the
eastbound lanes, and at ground level.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  5 of  7

                                                                                
Station ID: 8513825                         PUBLICATION DATE:  05/31/2005
Name:       SMITH POINT BRIDGE, NARROW BAY                    
            NY
NOAA Chart: 12353                           Latitude:   40° 44.3' N (  40.73830)
USGS Quad:  PATTERSQUASH ISLAND             Longitude:  72° 52.1' W ( -72.86830)


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


                         BENCH MARK STAMPING:  2 994
                         DESIGNATION:          851 3825 2 994

MONUMENTATION:           Bench Mark disk                       VM#:         4859
AGENCY:                  US Coastal and Geodetic Survey
                         (USC&GS)                              IDB PID#:        
SETTING CLASSIFICATION:  Concrete Monument                     OPUS PID:        
LATITUDE:   40° 44.3' N (  40.73830)          LONGITUDE:  72° 52.1' W ( -72.86830)


The bench mark is a disk set in a concrete monument in the triangular shaped
grass median on the east side of the traffic circle at the south end of William
Floyd Parkway at Smith Point Park, 23.29 m (76.4 ft) north of the south end of
the triangle, 21.88 m (71.8 ft) SE of the NW end of the triangle, 8.63 m (28.3
ft) east of the centerline of the traffic circle, and at ground level.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  6 of  7

                                                                                
Station ID: 8513825                         PUBLICATION DATE:  05/31/2005
Name:       SMITH POINT BRIDGE, NARROW BAY                    
            NY
NOAA Chart: 12353                           Latitude:   40° 44.3' N (  40.73830)
USGS Quad:  PATTERSQUASH ISLAND             Longitude:  72° 52.1' W ( -72.86830)


                            T I D A L   D A T U M S 


Tidal datums at SMITH POINT BRIDGE, NARROW BAY based on:

     LENGTH OF SERIES:      1 YEAR
     TIME PERIOD:           February 1990 - January 1991
     TIDAL EPOCH:           1983-2001
     CONTROL TIDE STATION:  8510560 MONTAUK, FORT POND BAY


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

     HIGHEST OBSERVED WATER LEVEL (12/04/1990)         =  0.978
     MEAN HIGHER HIGH WATER                     MHHW   =  0.446
     MEAN HIGH WATER                            MHW    =  0.397
     MEAN SEA LEVEL                             MSL    =  0.224
     MEAN TIDE LEVEL                            MTL    =  0.216
     MEAN LOW WATER                             MLW    =  0.036
     MEAN LOWER LOW WATER                       MLLW   =  0.000
     LOWEST  OBSERVED WATER LEVEL (02/21/1990)         = -0.372

North American Vertical Datum (NAVD88)

Bench Mark Elevation Information                In METERS above:

     Stamping or Designation                    MLLW        MHW

     3825 B 1989                                 4.645    4.248
     H 378 1956                                  2.389    1.992
     END NO 1 1962                               3.999    3.602
     3825 A 1989                                 2.806    2.409
     3825 C 1989                                 1.565    1.168
     SMITH POINT SET 1989                        5.511    5.114
     2 993                                       4.941    4.544
     2 994                                       5.755    5.358


                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  7 of  7

                                                                                
Station ID: 8513825                         PUBLICATION DATE:  05/31/2005
Name:       SMITH POINT BRIDGE, NARROW BAY                    
            NY
NOAA Chart: 12353                           Latitude:   40° 44.3' N (  40.73830)
USGS Quad:  PATTERSQUASH ISLAND             Longitude:  72° 52.1' W ( -72.86830)


                             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 8513825 SMITH POINT BRIDGE, NARROW BAY, NY

Revised: 08/08/2018
NOAA / National Ocean Service
Web site owner: Center for Operational Oceanographic Products and Services