U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Datums Page Page 1 of 6
Station ID: 8516607 PUBLICATION DATE: 12/05/2014
Name: HARRY TAPPEN MARINA, HEMPSTEAD HARBOR
NY
NOAA Chart: 12366 Latitude: 40° 50.1' N ( 40.83461)
USGS Quad: SEA CLIFF Longitude: 73° 39.1' W ( -73.65242)
To reach the station from the northern boulevard bridge over hempstead harbor,
proceed 0.5 km (0.3 mi) east on northern boulevard to the first right at the
east end of the bridge for old northern bouldevard, turn right and proceed 0.1
km (0.1 mi) south on the exit ramp and continue onto old northern bouldevard to
skillman street, turn right onto skillman street and then immediately turn right
at the first intersection with bryant avenue, proceed 1.6 km (1.0 mi) north on
bryant avenue to the intersection with glenwood road, turn left onto glenwood
road and continue 1.0 km (0.6 mi) north to the intersection with scudders lane,
turn left onto scudders land and continue 0.3 km (0.2 mi) west on scudders lane,
continue 1.3 km (0.8 mi) around the bend to the right and north on shore road to
the entrance to harry tappen beach, pool and marina and the tide station at the
nw corner of the marina. The bench marks are along the marina bulkhead and in
the park.
T I D A L B E N C H M A R K S
PRIMARY BENCH MARK STAMPING: 6607 D 2014
DESIGNATION: 851 6607 D
MONUMENTATION: Flange-encased Rod VM#: 21035
AGENCY: National Ocean Service IDB PID#:
SETTING CLASSIFICATION: Stainless steel rod in sleeve OPUS PID#: BBDM36
LATITUDE: 40° 50.1' N ( 40.83558) LONGITUDE: 73° 39.0' W ( -73.65042)
The bench mark is a flange encased rod set in the grass on the E side of the
parking lot S of the park entrance, 90.60 m (297.2 ft) SE of a flag pole, 42.15
m (138.3 ft) NW of the interior fence corner, 33.47 m (109.8 ft) N of the
bollard at the NE corner of the waste oil dump station, 9.68 m (31.8 ft) W of
the chain link fence along the E side of the park and 3.19 m (10.5 ft) E of the
curb face.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 2 of 6
Station ID: 8516607 PUBLICATION DATE: 12/05/2014
Name: HARRY TAPPEN MARINA, HEMPSTEAD HARBOR
NY
NOAA Chart: 12366 Latitude: 40° 50.1' N ( 40.83461)
USGS Quad: SEA CLIFF Longitude: 73° 39.1' W ( -73.65242)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 6607 B 2014
DESIGNATION: 851 6007 B
MONUMENTATION: Bench Mark disk VM#: 21036
AGENCY: National Ocean Service IDB PID#:
SETTING CLASSIFICATION: Retaining wall OPUS PID:
LATITUDE: 40° 50.1' N ( 40.83508) LONGITUDE: 73° 39.1' W ( -73.65139)
The bench mark is a disk set in the concrete cap of the sheet pile bulkhead,
33.80 m (110.9 ft) N of the center of a gate to the ramp down to the floating
dock, 24.08 m (79.0 ft) WSW of a fence corner at NE corner of parking area for
marina slip holders, 4.81 m (15.8 ft) S of the NE corner of the outside corner
of the seawall, 2.77 m (9.1 ft) WSW of the center of a water valve lid in the
sidewalk, 0.28 m (0.9 ft) W of E edge of concrete cap, and 0.32 m (1.0 ft) above
the sidewalk.
BENCH MARK STAMPING: 6607 C 2014
DESIGNATION: 851 6607 C
MONUMENTATION: Bench Mark disk VM#: 21037
AGENCY: National Ocean Service IDB PID#:
SETTING CLASSIFICATION: Retaining wall OPUS PID:
LATITUDE: 40° 50.0' N ( 40.83314) LONGITUDE: 73° 39.0' W ( -73.65011)
The bench mark is a disk set in the concrete cap of the sheet pile bulkhead,
29.63 m (97.2 ft) SW of a storm drain in the curb on the E side of the parking
lot, 22.75 m (74.6 ft) S of the center of a gate for a ramp leading down to
floating docks, 16.37 m (53.7 ft) N of the metal railing along the S side of the
marina property, 4.03 m (13.2 ft) N of the most southern light pole set on top
of the bulkhead and 0.24 m (0.8 ft) W of the E edge of the concrete cap.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 3 of 6
Station ID: 8516607 PUBLICATION DATE: 12/05/2014
Name: HARRY TAPPEN MARINA, HEMPSTEAD HARBOR
NY
NOAA Chart: 12366 Latitude: 40° 50.1' N ( 40.83461)
USGS Quad: SEA CLIFF Longitude: 73° 39.1' W ( -73.65242)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 6607 A 2014
DESIGNATION: 851 6607 A
MONUMENTATION: Bench Mark disk VM#: 21038
AGENCY: National Ocean Service IDB PID#:
SETTING CLASSIFICATION: Retaining wall OPUS PID:
LATITUDE: 40° 50.1' N ( 40.83467) LONGITUDE: 73° 39.1' W ( -73.65239)
The bench mark is a disk set in the concrete cap of the sheet pile bulkhead, it
is 95.05 m (311.8 ft) WSW of the NE corner of the marina basin, 33.45 m (109.7
ft) ENE of the SW corner at the end of the dock, 6.24 m (20.5 ft) SSW of the S
side of the concrete cap that runs along the N side of the dock, 4.46 m (14.6
ft) E of the most W light pole and 0.30 m (1.0 ft) SSW of the N edge of the
concrete cap.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 4 of 6
Station ID: 8516607 PUBLICATION DATE: 12/05/2014
Name: HARRY TAPPEN MARINA, HEMPSTEAD HARBOR
NY
NOAA Chart: 12366 Latitude: 40° 50.1' N ( 40.83461)
USGS Quad: SEA CLIFF Longitude: 73° 39.1' W ( -73.65242)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: R07E 19N AZ
DESIGNATION: 07E 19N AZ
MONUMENTATION: Flange-encased Rod VM#: 21039
AGENCY: National Ocean Service IDB PID#: KU4755
SETTING CLASSIFICATION: Stainless steel rod in sleeve OPUS PID:
LATITUDE: 40° 50.3' N ( 40.83792) LONGITUDE: 73° 39.2' W ( -73.65311)
The bench mark is a flange encased rod set the gravel fill on the small
peninsula bordered by rock riprap and NW of the swimming pool, 26.63 m (87.4 ft)
WNW of the NW corner of the fence around the swimming pool, 14.82 m (48.6 ft) W
of a large deciduous tree, 6.60 m (21.7 ft) E of the inland side of the rock
riprap at the W point of the peninsula, 6.45 m (21.2 ft) W of a metal bench and
4.75 m (15.6 ft) WNW of the center of the end of the asphalt path.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 5 of 6
Station ID: 8516607 PUBLICATION DATE: 12/05/2014
Name: HARRY TAPPEN MARINA, HEMPSTEAD HARBOR
NY
NOAA Chart: 12366 Latitude: 40° 50.1' N ( 40.83461)
USGS Quad: SEA CLIFF Longitude: 73° 39.1' W ( -73.65242)
T I D A L D A T U M S
Tidal datums at HARRY TAPPEN MARINA, HEMPSTEAD HARBOR based on:
LENGTH OF SERIES: 3 MONTHS
TIME PERIOD: May 2014 - July 2014
TIDAL EPOCH: 1983-2001
CONTROL TIDE STATION: 8516945 KINGS POINT, LONG ISLAND SOUND
Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in METERS:
MEAN HIGHER HIGH WATER MHHW = 2.400
MEAN HIGH WATER MHW = 2.291
MEAN SEA LEVEL MSL = 1.184
MEAN TIDE LEVEL MTL = 1.181
MEAN LOW WATER MLW = 0.070
MEAN LOWER LOW WATER MLLW = 0.000
North American Vertical Datum (NAVD88)
Bench Mark Elevation Information In METERS above:
Stamping or Designation MLLW MHW
6607 D 2014 4.153 1.862
6607 B 2014 4.276 1.985
6607 C 2014 4.267 1.976
6607 A 2014 4.278 1.987
R07E 19N AZ 3.194 0.903
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 6 of 6
Station ID: 8516607 PUBLICATION DATE: 12/05/2014
Name: HARRY TAPPEN MARINA, HEMPSTEAD HARBOR
NY
NOAA Chart: 12366 Latitude: 40° 50.1' N ( 40.83461)
USGS Quad: SEA CLIFF Longitude: 73° 39.1' W ( -73.65242)
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.