U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Datums Page Page 1 of 5
Station ID: 8514779 PUBLICATION DATE: 12/30/2014
Name: SEAVIEW FERRY DOCK, FIRE ISLAND INLET
NY
NOAA Chart: 12352 Latitude: 40° 39.0' N ( 40.64925)
USGS Quad: BAY SHORE EAST Longitude: 73° 9.0' W ( -73.15061)
To reach the tidal bench marks from the intersection of Maple Avenue and Montauk
Highway/West Main Street in Bay Shore, proceed 0.8 km (0.5 mi) SE on Maple Ave
to 104 Maple Avenue and the entrance on the right for Fire Island Ferries, park
and proceed SE and east 13.2 km (8.2 mi) on the ferry to the Seaview boat basin.
The benchmarks are set along the Central Walk, Fairway Avenue, and Bay View
Walk and the tide gauge is located inside the Seaview boat basin east of the
entrance channel.
T I D A L B E N C H M A R K S
PRIMARY BENCH MARK STAMPING: 4779 A 2013
DESIGNATION: 851 4779 A
MONUMENTATION: Metal Rod VM#: 20914
AGENCY: National Ocean Service (NOS) IDB PID#:
SETTING CLASSIFICATION: Stainless steel rod in sleeve OPUS PID:
LATITUDE: 40° 38.9' N ( 40.64850) LONGITUDE: 73° 9.0' W ( -73.15069)
The primary bench mark is a flange encased rod located near the Seaview Ferry
Dock on Fire Island, 26.02 m (85.4 ft) E of the SW corner of the Seaview Market
store, 13.56 m (44.5 ft) SE of the SW corner of the ferry boat basin, 5.50 m
(18.0 ft) south of the centerline of the Brick Street, 5.44 m (17.8 ft) WNW of
light power pole #10, and 2.70 m (8.9 ft) NW of red fire hydrant #34507. The
datum point is set 6 cm (0.2 ft) below grade, being the top of a stainless steel
rod driven 17.64 m (57.9 ft) to refusal, and encased in a 5-inch NOS logo cover
with concrete kickblock.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 2 of 5
Station ID: 8514779 PUBLICATION DATE: 12/30/2014
Name: SEAVIEW FERRY DOCK, FIRE ISLAND INLET
NY
NOAA Chart: 12352 Latitude: 40° 39.0' N ( 40.64925)
USGS Quad: BAY SHORE EAST Longitude: 73° 9.0' W ( -73.15061)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 4779 B 2013
DESIGNATION: 851 4779 B
MONUMENTATION: Metal Rod VM#: 20915
AGENCY: National Ocean Service (NOS) IDB PID#:
SETTING CLASSIFICATION: Stainless steel rod in sleeve OPUS PID#: BBDG80
LATITUDE: 40° 38.9' N ( 40.64875) LONGITUDE: 73° 9.0' W ( -73.14961)
The bench mark is a flange encased rod located near the Seaview Ferry Dock on
Fire Island, 15.72 m (51.6 ft) WSW of the center of a man-gate with access to
the dock, 14.67 m (48.1 ft) NNE of the NE corner of Seaview Community Doctors
building, 8.92 m (29.3 ft) SW of a power pole with Fairway Street sign
attached, 7.68 m (25.2 ft) east of a fire hydrant, and 2.43 m (8.0 ft) north of
a 10 cm x 15 cm (4 in x 6 in) wood post with a concrete kickblock marking
telephone cables. The datum point is set 5 cm (0.2 ft) below grade, being the
top of a stainless steel rod driven 17.17 m (56.3 ft) to refusal, and encased in
a 5-inch NOS logo cover with concrete kickblock.
BENCH MARK STAMPING: 4779 C 2013
DESIGNATION: 851 4779 C
MONUMENTATION: Tidal Station disk VM#: 20916
AGENCY: National Ocean Service (NOS) IDB PID#:
SETTING CLASSIFICATION: Concrete footing OPUS PID:
LATITUDE: 40° 38.8' N ( 40.64703) LONGITUDE: 73° 8.9' W ( -73.14836)
The bench mark is a disk set in the SE concrete footing for a 3 m (9.8 ft) wide
by 11 m (36.1 ft) steel tank inside the fenced yard for the Seaview water
treatment plant, 27.50 m (90.2 ft) NE of the centerline of Fairway Avenue, 6.41
m (21.0 ft) ENE of the NW corner of the garage building, 1.99 m (6.5 ft) NW of
the NE corner of the garage building, and 0.34 m (1.1 ft) S of the tank footing.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 3 of 5
Station ID: 8514779 PUBLICATION DATE: 12/30/2014
Name: SEAVIEW FERRY DOCK, FIRE ISLAND INLET
NY
NOAA Chart: 12352 Latitude: 40° 39.0' N ( 40.64925)
USGS Quad: BAY SHORE EAST Longitude: 73° 9.0' W ( -73.15061)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 4779 D 2013
DESIGNATION: 851 4779 D
MONUMENTATION: Tidal Station disk VM#: 20917
AGENCY: National Ocean Service (NOS) IDB PID#:
SETTING CLASSIFICATION: Concrete Footing OPUS PID:
LATITUDE: 40° 38.9' N ( 40.64906) LONGITUDE: 73° 8.7' W ( -73.14447)
The bench mark is a disk set in the top of a cinder block retaining wall in the
Seaview playground north of the community tennis courts, 31.94 m (104.8 ft) SSE
of the seawall along Great South Bay on the N side of Fire Island, 16.26 m (26.2
ft) N of the centerline of Bay View Walk, 3.55 m (11.6 ft) NNE of the post at
mid-court for the easternmost basketball hoop, 3.29 m (10.8 ft) south of the SW
corner of the elevated public restroom building, and 1.34 m (4.4 ft) above
grade.
BENCH MARK STAMPING: 4779 E 2013
DESIGNATION: 851 4779 E
MONUMENTATION: Tidal Station disk VM#: 20918
AGENCY: National Ocean Service (NOS) IDB PID#:
SETTING CLASSIFICATION: Concrete Foundation OPUS PID:
LATITUDE: 40° 38.9' N ( 40.64908) LONGITUDE: 73° 8.6' W ( -73.14403)
The bench mark is a disk set at the S end of the overhead door at the top of the
ramp on the west side of the old incinerator building, 26.97 m (88.5 ft) SE of
the SE corner of the small barge basin, 20.50 m (67.3 ft) NE of the center of
the gate from Bay View Walk, 11.25 m (36.9 ft) south of the west side of the
incinerator chimney, 3.61 m (11.8 ft) NW of the SW corner of the incinerator
building, and 0.29 m (1.0 ft) NW of the south side of the overhead door opening.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 4 of 5
Station ID: 8514779 PUBLICATION DATE: 12/30/2014
Name: SEAVIEW FERRY DOCK, FIRE ISLAND INLET
NY
NOAA Chart: 12352 Latitude: 40° 39.0' N ( 40.64925)
USGS Quad: BAY SHORE EAST Longitude: 73° 9.0' W ( -73.15061)
T I D A L D A T U M S
Tidal datums at SEAVIEW FERRY DOCK, FIRE ISLAND INLET based on:
LENGTH OF SERIES: 1 MONTH
TIME PERIOD: August 2014 - August 2014
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:
MEAN HIGHER HIGH WATER MHHW = 0.442
MEAN HIGH WATER MHW = 0.399
MEAN TIDE LEVEL MTL = 0.220
MEAN SEA LEVEL MSL = 0.215
MEAN LOW WATER MLW = 0.041
MEAN LOWER LOW WATER MLLW = 0.000
North American Vertical Datum (NAVD88)
Bench Mark Elevation Information In METERS above:
Stamping or Designation MLLW MHW
4779 A 2013 1.092 0.693
4779 B 2013 1.329 0.930
4779 C 2013 2.029 1.630
4779 D 2013 2.505 2.106
4779 E 2013 2.633 2.234
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 5 of 5
Station ID: 8514779 PUBLICATION DATE: 12/30/2014
Name: SEAVIEW FERRY DOCK, FIRE ISLAND INLET
NY
NOAA Chart: 12352 Latitude: 40° 39.0' N ( 40.64925)
USGS Quad: BAY SHORE EAST Longitude: 73° 9.0' W ( -73.15061)
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.