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National Ocean Service
Datums Page Page 1 of 7
Station ID: 8515102 PUBLICATION DATE: 07/26/2004
Name: BAYSHORE, LONG ISLAND
NY
NOAA Chart: 12352 Latitude: 40° 43.0' N ( 40.71670)
USGS Quad: Bay Shore East Longitude: 73° 14.4' W ( -73.24000)
To reach the tidal bench marks from the junction of Highway 27A (Montauk
Highway) and Maple Avenue in Bay Shore, proceed south for 0.8 km (0.5 mi)
following signs to the Fire Island Ferries. The tide gage was located at the Bay
Shore Marine Basin on the north wall as you come in the door, in the Marine
Supply Store. The bench marks are located on the marine basin property.
T I D A L B E N C H M A R K S
PRIMARY BENCH MARK STAMPING: NO 1 1972
DESIGNATION: 851 5102 TIDAL 1
MONUMENTATION: Tidal Station disk VM#: 16127
AGENCY: National Ocean Survey (NOS) IDB PID#:
SETTING CLASSIFICATION: Concrete flagpole foundation OPUS PID:
LATITUDE: 40° 43.0' N ( 40.71670) LONGITUDE: 73° 14.4' W ( -73.24000)
The primary bench mark is a disk set in the concrete base of a flag pole at the
SE corner of the Bay Shore Basin Marine, Inc. office building, located at 121
Maple Avenue.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 2 of 7
Station ID: 8515102 PUBLICATION DATE: 07/26/2004
Name: BAYSHORE, LONG ISLAND
NY
NOAA Chart: 12352 Latitude: 40° 43.0' N ( 40.71670)
USGS Quad: Bay Shore East Longitude: 73° 14.4' W ( -73.24000)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: NO 3 1933
DESIGNATION: TIDAL 3 STA II 67
MONUMENTATION: Tidal Station disk VM#: 16125
AGENCY: US Coast and Geodetic Survey
(USC&GS) IDB PID#: KU0668
SETTING CLASSIFICATION: Concrete curb OPUS PID:
LATITUDE: 40° 42.8' N ( 40.71330) LONGITUDE: 73° 14.5' W ( -73.24170)
The bench mark is a disk set in the concrete curbing of the last street corner
on the NE side of Ocean Avenue, at the corner of 133 Ocean Avenue, and about
0.15 m (0.5 ft) from the outer edge of the curbing.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 3 of 7
Station ID: 8515102 PUBLICATION DATE: 07/26/2004
Name: BAYSHORE, LONG ISLAND
NY
NOAA Chart: 12352 Latitude: 40° 43.0' N ( 40.71670)
USGS Quad: Bay Shore East Longitude: 73° 14.4' W ( -73.24000)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: NO 4 1950
DESIGNATION: TIDAL 4 STA II 67
MONUMENTATION: Tidal Station disk VM#: 16126
AGENCY: US Coast and Geodetic Survey
(USC&GS) IDB PID#: KU0670
SETTING CLASSIFICATION: Concrete storm sewer foundation OPUS PID:
LATITUDE: 40° 42.8' N ( 40.71330) LONGITUDE: 73° 14.4' W ( -73.24000)
The bench mark is a disk set in the concrete foundation of a storm sewer located
at the NW corner of the intersection of Bayview Street and Burnett Avenue, and
0.3 m (1 ft) NE of the NW corner of the sewer foundation.
BENCH MARK STAMPING: NO 2 1972
DESIGNATION: 851 5102 TIDAL 2
MONUMENTATION: Tidal Station disk VM#: 16128
AGENCY: National Ocean Survey (NOS) IDB PID#:
SETTING CLASSIFICATION: Concrete hoist foundation OPUS PID:
LATITUDE: 40° 43.0' N ( 40.71670) LONGITUDE: 73° 14.4' W ( -73.24000)
The bench mark is a disk set in the concrete foundation of the Bay Shore Marine
Basin's small boat hoist, 7.47 m (24.5 ft) NE of the NE corner of the dry boat
storage shed, 5.5 m (18.0 ft) south of the hoist, and 0.55 m (1.8 ft) west of a
retaining wall.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 4 of 7
Station ID: 8515102 PUBLICATION DATE: 07/26/2004
Name: BAYSHORE, LONG ISLAND
NY
NOAA Chart: 12352 Latitude: 40° 43.0' N ( 40.71670)
USGS Quad: Bay Shore East Longitude: 73° 14.4' W ( -73.24000)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: NO 3 1972
DESIGNATION: 851 5102 TIDAL 3
MONUMENTATION: Tidal Station disk VM#: 16129
AGENCY: National Ocean Survey (NOS) IDB PID#:
SETTING CLASSIFICATION: Retaining wall OPUS PID:
LATITUDE: 40° 43.0' N ( 40.71670) LONGITUDE: 73° 14.4' W ( -73.24000)
The bench mark is a disk set in the top of the retaining wall at the NW corner
of Flynn's Restaurant, located on the south end of Maple Street, 9.4 m (31 ft)
east of the centerline line of Maple Street, 1.5 m (5 ft) south of the
southernmost miniature light house at the entrance to the north parking lot of
the restaurant, and 0.6 m (2 ft) above the sidewalk.
BENCH MARK STAMPING: NO 4 1973
DESIGNATION: 851 5102 TIDAL 4
MONUMENTATION: Tidal Station disk VM#: 16130
AGENCY: National Ocean Survey (NOS) IDB PID#:
SETTING CLASSIFICATION: Concrete monument OPUS PID:
LATITUDE: 40° 43.0' N ( 40.71670) LONGITUDE: 73° 14.4' W ( -73.24000)
The bench mark is a disk set in in a concrete monument at the SE corner of the
northern boat shed at the Bay Shore Marine Basin, 38.16 m (125.2 ft) north of
the NE corner of the southern boat shed, 18.11 m (59.4 ft) south of the fence on
the northern edge of the Marine Basin yard, and 11.22 m (36.8 ft) NW of the west
end of the northern rail of the boat hoist located in the north side of the
yard.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 5 of 7
Station ID: 8515102 PUBLICATION DATE: 07/26/2004
Name: BAYSHORE, LONG ISLAND
NY
NOAA Chart: 12352 Latitude: 40° 43.0' N ( 40.71670)
USGS Quad: Bay Shore East Longitude: 73° 14.4' W ( -73.24000)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: NO 5 1973
DESIGNATION: 851 5102 TIDAL 5
MONUMENTATION: Tidal Station disk VM#: 16131
AGENCY: National Ocean Survey (NOS) IDB PID#:
SETTING CLASSIFICATION: Concrete monument OPUS PID:
LATITUDE: 40° 43.0' N ( 40.71670) LONGITUDE: 73° 14.4' W ( -73.24000)
The bench mark is a disk set in a concrete monument next to the south gate to
the Bay Shore Marine Basin, 34.47 m (113.1 ft) SW of the SW corner of the
northern boat shed, 31.73 m (104.1 ft) west of the NW corner of the southern
boat shed, 19.57 m (64.2 ft) east of the centerline of Maple Avenue, 18.99 m
(62.3 ft) SSE of the SE corner of the guard shack at the northern entrance, and
15.73 m (51.6 ft) north of the NE corner of a small seafood restaurant building.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 6 of 7
Station ID: 8515102 PUBLICATION DATE: 07/26/2004
Name: BAYSHORE, LONG ISLAND
NY
NOAA Chart: 12352 Latitude: 40° 43.0' N ( 40.71670)
USGS Quad: Bay Shore East Longitude: 73° 14.4' W ( -73.24000)
T I D A L D A T U M S
Tidal datums at BAYSHORE, LONG ISLAND based on:
LENGTH OF SERIES: 1 YEAR
TIME PERIOD: January 1979 - December 1979
TIDAL EPOCH: 1983-2001
CONTROL TIDE STATION: 8531680 SANDY HOOK
Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in METERS:
MEAN HIGHER HIGH WATER MHHW = 0.376
MEAN HIGH WATER MHW = 0.323
MEAN SEA LEVEL MSL = 0.183
MEAN TIDE LEVEL MTL = 0.173
MEAN LOW WATER MLW = 0.022
MEAN LOWER LOW WATER MLLW = 0.000
North American Vertical Datum (NAVD88)
Bench Mark Elevation Information In METERS above:
Stamping or Designation MLLW MHW
NO 1 1972 1.002 0.679
NO 3 1933 0.454 0.131
NO 4 1950 1.014 0.691
NO 2 1972 0.669 0.346
NO 3 1972 1.420 1.097
NO 4 1973 1.480 1.157
NO 5 1973 1.203 0.880
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 7 of 7
Station ID: 8515102 PUBLICATION DATE: 07/26/2004
Name: BAYSHORE, LONG ISLAND
NY
NOAA Chart: 12352 Latitude: 40° 43.0' N ( 40.71670)
USGS Quad: Bay Shore East Longitude: 73° 14.4' W ( -73.24000)
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.