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Bench Mark Sheet for 8515921, LLOYD HARBOR LIGHTHOUSE 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Superseded Epoch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Small blue map location marker Unpublished bench mark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.

Error: There is no bench mark map available for 8515921 LLOYD HARBOR LIGHTHOUSE, NY
Printable version

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
Datums Page                                                        Page  1 of  4

                                                                                
Station ID: 8515921                                PUBLICATION DATE:  07/02/2003
Name:       LLOYD HARBOR LIGHTHOUSE                           
            NEW YORK
NOAA Chart: 12365                                  Latitude:         40° 54.6' N
USGS Quad:  LOLYD HARBOR                           Longitude:        73° 25.9' W


To reach the tidal bench marks from New York City, proceed east on Long Island
Expressway for 35 km (22 mi) to State Highway 110, go north on State Highway 110
to Huntington Harbor in Huntington, then continue by boat along the privately
maintained harbor channel for approximately 4.0 km (2.2 nm) to Lloyd Harbor. 
The bench marks are in the lighthouse foundation and in the boulders surrounding
the lighthouse base.  The tide gauge and staff were located 9 m (30 ft) SW of
the lighthouse.


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


                 PRIMARY BENCH MARK STAMPING:  5921 A 1990
                         DESIGNATION:          851 5921 A

MONUMENTATION:           Tidal Station disk                        VM#:     5101
AGENCY:                  National Ocean Service (NOS)              PID:         
SETTING CLASSIFICATION:  Boulder


The primary bench mark is a disk set in a 2 m X 2 m (5 ft X 6 ft) boulder, and
1.52 m (5.0 ft) east of the SE corner of the lighthouse.



                         BENCH MARK STAMPING:  5921 B 1990
                         DESIGNATION:          851 5921 B

MONUMENTATION:           Tidal Station disk                        VM#:     5102
AGENCY:                  National Ocean Service (NOS)              PID:         
SETTING CLASSIFICATION:  Concrete foundation


The bench mark is a disk set in the foundation of the lighthouse, and 0.61 m
(2.0 ft) east of the NE corner of the lighthouse.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  2 of  4

                                                                                
Station ID: 8515921                                PUBLICATION DATE:  07/02/2003
Name:       LLOYD HARBOR LIGHTHOUSE                           
            NEW YORK
NOAA Chart: 12365                                  Latitude:         40° 54.6' N
USGS Quad:  LOLYD HARBOR                           Longitude:        73° 25.9' W


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


                         BENCH MARK STAMPING:  5921 C 1990
                         DESIGNATION:          851 5921 C

MONUMENTATION:           Tidal Station disk                        VM#:     5103
AGENCY:                  National Ocean Service (NOS)              PID:         
SETTING CLASSIFICATION:  Boulder


The bench mark is set in a 1 m x 2 m (4 ft x 6 ft) boulder, and 9 m (30 ft)
north of the NW corner of the lighthouse.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  3 of  4

                                                                                
Station ID: 8515921                                PUBLICATION DATE:  07/02/2003
Name:       LLOYD HARBOR LIGHTHOUSE                           
            NEW YORK
NOAA Chart: 12365                                  Latitude:         40° 54.6' N
USGS Quad:  LOLYD HARBOR                           Longitude:        73° 25.9' W


                            T I D A L   D A T U M S 


Tidal datums at LLOYD HARBOR LIGHTHOUSE based on:

     LENGTH OF SERIES:      2 MONTHS
     TIME PERIOD:           July 1990 - August 1990
     TIDAL EPOCH:           1983-2001
     CONTROL TIDE STATION:  8518490 NEW ROCHELLE


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

     MEAN HIGHER HIGH WATER                     MHHW   =  2.318
     MEAN HIGH WATER                            MHW    =  2.209
     MEAN SEA LEVEL                             MSL    =  1.143
     MEAN TIDE LEVEL                            MTL    =  1.137
     MEAN LOW WATER                             MLW    =  0.065
     MEAN LOWER LOW WATER                       MLLW   =  0.000



Bench Mark Elevation Information                In METERS above:

     Stamping or Designation                    MLLW        MHW

     5921 A 1990                                 2.103   -0.106
     5921 B 1990                                 3.316    1.107
     5921 C 1990                                 3.292    1.083


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

                                                                                
Station ID: 8515921                                PUBLICATION DATE:  07/02/2003
Name:       LLOYD HARBOR LIGHTHOUSE                           
            NEW YORK
NOAA Chart: 12365                                  Latitude:         40° 54.6' N
USGS Quad:  LOLYD HARBOR                           Longitude:        73° 25.9' W


                             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 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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Revised: 10/15/2013
NOAA / National Ocean Service
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