U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Datums Page Page 1 of 7
Station ID: 8510719 PUBLICATION DATE: 05/29/2009
Name: SILVER EEL POND, FISHERS IS.
NY
NOAA Chart: 13214 Latitude: 41° 15.4' N ( 41.25670)
USGS Quad: New London Longitude: 72° 1.8' W ( -72.03000)
To reach the tidal bench marks from Fishers Island Ferry dock on Fishers Island,
proceed off the ferry and turn right into the U.S. Coast Guard Fishers Island
Station. The bench marks are along the harbor perimeter and out toward the
airport. The tide gauge and staff were in the west corner of the harbor on the
U.S. Coast Guard bulkhead.
T I D A L B E N C H M A R K S
PRIMARY BENCH MARK STAMPING: BM 1 1961
DESIGNATION: 851 0719 TIDAL 1
MONUMENTATION: Tidal Station disk VM#: 11245
AGENCY: US Coast and Geodetic Survey
(USC&GS) IDB PID#:
SETTING CLASSIFICATION: Concrete slab OPUS PID:
LATITUDE: 41° 15.4' N ( 41.25670) LONGITUDE: 72° 1.9' W ( -72.03170)
The primary bench mark is a disk set in the center of a 3 m x 3 m (10 ft x 10
ft) concrete slab near the intersection of the stone jetty and the shoreline, 60
m (197 ft) north of bench mark NO STAMPING 1, 40.93 m (134.3 ft) NW of the NE
corner a of U.S. Coast Guard bulkhead at the harbor entrance, and 2.16 m (7.1
ft) south of the north corner of the concrete slab.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 2 of 7
Station ID: 8510719 PUBLICATION DATE: 05/29/2009
Name: SILVER EEL POND, FISHERS IS.
NY
NOAA Chart: 13214 Latitude: 41° 15.4' N ( 41.25670)
USGS Quad: New London Longitude: 72° 1.8' W ( -72.03000)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: BM 2 1961
DESIGNATION: 851 0719 TIDAL 2
MONUMENTATION: Tidal Station disk VM#: 11246
AGENCY: US Coast and Geodetic Survey
(USC&GS) IDB PID#:
SETTING CLASSIFICATION: Concrete slab OPUS PID:
LATITUDE: 41° 15.4' N ( 41.25670) LONGITUDE: 72° 1.9' W ( -72.03170)
The bench mark is a disk set in a concrete slab in the center of a traffic
island for ferry truck scales at the foot of the Fishers Island Ferry dock, near
the ferry office building, 54 m (176 ft) NE of the northern end of School Road,
17.50 m (57.4 ft) SW of the main vehicle loading ramp, 16.61 m (54.5 ft) south
of the western gate post to the U.S. Coast Guard facility, 9.75 m (32.0 ft)
north of the west corner of the ferry office building, 2.56 m (8.4 ft) NW of the
north curb of the truck scales, and 2.29 m (7.5 ft) NE of a manhole cover in the
center of the traffic island.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 3 of 7
Station ID: 8510719 PUBLICATION DATE: 05/29/2009
Name: SILVER EEL POND, FISHERS IS.
NY
NOAA Chart: 13214 Latitude: 41° 15.4' N ( 41.25670)
USGS Quad: New London Longitude: 72° 1.8' W ( -72.03000)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING:
DESIGNATION: TIDAL 4 STA II 26
ALIAS: No Stamping 1
MONUMENTATION: Rivet VM#: 11247
AGENCY: US Coast and Geodetic Survey
(USC&GS) IDB PID#: LX0336
SETTING CLASSIFICATION: Concrete step OPUS PID:
LATITUDE: 41° 15.4' N ( 41.25670) LONGITUDE: 72° 1.9' W ( -72.03170)
The bench mark is a monel rivet set in the NW end of the bottom step on the
front of the NW wing of the old brick U.S. Coast Guard building (formerly U.S.
Post Office), 52 m (171 ft) SW of the NE corner of the U.S. Coast Guard bulkhead
at the harbor entrance, 3.44 m (11.3 ft) east of the north corner of the NW
wing, 2.44 m (8.0 ft) north of the center of the doorway to the NW wing, and
0.21 m (0.7 ft) above the ground level.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 4 of 7
Station ID: 8510719 PUBLICATION DATE: 05/29/2009
Name: SILVER EEL POND, FISHERS IS.
NY
NOAA Chart: 13214 Latitude: 41° 15.4' N ( 41.25670)
USGS Quad: New London Longitude: 72° 1.8' W ( -72.03000)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING:
DESIGNATION: TIDAL 2 STA II 26
ALIAS: No Stamping 2
MONUMENTATION: Rivet VM#: 11248
AGENCY: US Coast and Geodetic Survey
(USC&GS) IDB PID#: LX0334
SETTING CLASSIFICATION: Concrete step OPUS PID:
LATITUDE: 41° 15.4' N ( 41.25670) LONGITUDE: 72° 1.9' W ( -72.03170)
The bench mark is a monel rivet set in the north end of the bottom of an old
concrete step leading from Harbor Road to a steel sculpture on the east side of
Silver Eel Cove, on the east side of the road leading around the harbor (Harbor
Road), 43 m (142 ft) south of the intersection of Harbor and Winthrop Roads, 39
m (127 ft) NE of the NE corner of an old brick pumphouse (now a residence on the
harbor's edge), 26.03 m (85.4 ft) SE of a high section of stone retaining wall
on the north side of the road, 22 m (72 ft) SE of power pole #306, 3.57 m (11.7
ft) west of the steel sculpture and 2 m (7 ft) north of the south edge of the
steps. NOTE: The bench mark has been designated 2 (1943)
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 5 of 7
Station ID: 8510719 PUBLICATION DATE: 05/29/2009
Name: SILVER EEL POND, FISHERS IS.
NY
NOAA Chart: 13214 Latitude: 41° 15.4' N ( 41.25670)
USGS Quad: New London Longitude: 72° 1.8' W ( -72.03000)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING:
DESIGNATION: TIDAL 3 STA II 26
MONUMENTATION: Rivet VM#: 11249
AGENCY: US Coast and Geodetic Survey
(USC&GS) IDB PID#: LX0335
SETTING CLASSIFICATION: Concrete tower foundation OPUS PID:
LATITUDE: 41° 15.4' N ( 41.25670) LONGITUDE: 72° 1.9' W ( -72.03170)
The bench mark is a monel rivet set in the center of a 3 m (10 ft) square
concrete foundation of an old observation tower near the entrance road to the
airport from Whistler Avenue, 44.56 m (146.2 ft) SE of the SE corner of a 6 m x
6 m (20 ft x 20 ft) concrete block garage, 32.25 m (105.8 ft) NW of the NE
corner of a concrete block airport building, 13.20 m (43.3 ft) west of the
centerline of the entrance road to the airport, 11.73 m (38.5 ft) SW of a fire
hydrant, 23.16 m (76.0 ft) west of power pole w/transformer #317 and 1 m (3 ft)
above ground.
BENCH MARK STAMPING: 0719 A 2003
DESIGNATION: 851 0719 A
MONUMENTATION: Flange-encased Rod VM#: 17368
AGENCY: National Ocean Service (NOS) IDB PID#:
SETTING CLASSIFICATION: Stainless steel rod in sleeve OPUS PID:
LATITUDE: 41° 15.4' N ( 41.25670) LONGITUDE: 72° 1.9' W ( -72.03170)
The bench mark is a flange-encased rod set near the SW corner of the fence
enclosing the US Coast Guard station, 23.41 m (76.8 ft) NW of the NW corner of
the ferry building, 23 m (75 ft) south of the southern corner of the Coast Guard
building, and 4.5 m (14.8 ft) north of the SW corner post of the fence. The
datum point is the top of a stainless steel rod driven an unspecified depth,
inside a 1 m (3 ft) sleeve, and encased in a 5-inch NOS logo cap.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 6 of 7
Station ID: 8510719 PUBLICATION DATE: 05/29/2009
Name: SILVER EEL POND, FISHERS IS.
NY
NOAA Chart: 13214 Latitude: 41° 15.4' N ( 41.25670)
USGS Quad: New London Longitude: 72° 1.8' W ( -72.03000)
T I D A L D A T U M S
Tidal datums at SILVER EEL POND, FISHERS IS. based on:
LENGTH OF SERIES: 3 YEARS
TIME PERIOD: December 2003 - November 2006
TIDAL EPOCH: 1983-2001
CONTROL TIDE STATION: 8461490 NEW LONDON, THAMES RIVER
Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in METERS:
HIGHEST OBSERVED WATER LEVEL (12/16/2005) = 1.630
MEAN HIGHER HIGH WATER MHHW = 0.860
MEAN HIGH WATER MHW = 0.771
MEAN SEA LEVEL MSL = 0.432
MEAN TIDE LEVEL MTL = 0.415
MEAN LOW WATER MLW = 0.058
MEAN LOWER LOW WATER MLLW = 0.000
LOWEST OBSERVED WATER LEVEL (03/09/2005) = -0.610
North American Vertical Datum (NAVD88)
Bench Mark Elevation Information In METERS above:
Stamping or Designation MLLW MHW
BM 1 1961 2.508 1.737
BM 2 1961 2.498 1.727
TIDAL 4 STA II 26 2.554 1.783
TIDAL 2 STA II 26 3.543 2.772
TIDAL 3 STA II 26 6.837 6.066
0719 A 2003 2.359 1.588
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 7 of 7
Station ID: 8510719 PUBLICATION DATE: 05/29/2009
Name: SILVER EEL POND, FISHERS IS.
NY
NOAA Chart: 13214 Latitude: 41° 15.4' N ( 41.25670)
USGS Quad: New London Longitude: 72° 1.8' W ( -72.03000)
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.