U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
Datums Page                                                        Page  1 of  5

                                                                                
Station ID: 8515786                         PUBLICATION DATE:  11/10/2010
Name:       EATONS NECK, HUNTINGTON BAY                       
            NY
NOAA Chart: 11365                           Latitude:   40° 57.2' N (  40.95330)
USGS Quad:  LLOYD HARBOR                    Longitude:  73° 24.0' W ( -73.40000)





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


                 PRIMARY BENCH MARK STAMPING:  5786 A 1995
                         DESIGNATION:          851 5786 A

MONUMENTATION:           Tidal Station disk                    VM#:        16820
AGENCY:                  National Ocean Service (NOS)          IDB PID#:        
SETTING CLASSIFICATION:  Concrete deck                         OPUS PID:        
LATITUDE:   40° 57.2' N (  40.95330)          LONGITUDE:  73° 23.9' W ( -73.39830)


The primary bench mark is a disk set in concrete deck at the SE corner of the
boat basin bulkhead, 23.01  m (75.5 ft) SW of the SW corner of the boathouse,
11.00 m (36.1 ft) west of the NW corner of the storage shed, and 1.01 m (3.3 ft)
south of the cleat.



                         BENCH MARK STAMPING:  5786 B 1995
                         DESIGNATION:          851 5786 B

MONUMENTATION:           Tidal Station disk                    VM#:        16821
AGENCY:                  National Ocean Service (NOS)          IDB PID#:        
SETTING CLASSIFICATION:  Concrete monument                     OPUS PID:        
LATITUDE:   40° 57.2' N (  40.95330)          LONGITUDE:  73° 23.9' W ( -73.39830)


The bench mark is a disk set in concrete monument located down near the coast
guard dock,  13.01 m (42.7 ft) south of the door on the south side of the
boathouse, 3.99 m (13.1 ft) west of the NE corner of the storage shed, and 0.21
m (0.7 ft) north of the storage shed foundation.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  2 of  5

                                                                                
Station ID: 8515786                         PUBLICATION DATE:  11/10/2010
Name:       EATONS NECK, HUNTINGTON BAY                       
            NY
NOAA Chart: 11365                           Latitude:   40° 57.2' N (  40.95330)
USGS Quad:  LLOYD HARBOR                    Longitude:  73° 24.0' W ( -73.40000)


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


                         BENCH MARK STAMPING:  5786 C 1995
                         DESIGNATION:          851 5786 C

MONUMENTATION:           Tidal Station disk                    VM#:        16822
AGENCY:                  National Ocean Service (NOS)          IDB PID#:        
SETTING CLASSIFICATION:  Retaining wall                        OPUS PID:        
LATITUDE:   40° 57.3' N (  40.95500)          LONGITUDE:  73° 23.9' W ( -73.39830)


The bench mark is a disk set in a concrete rataining wall surrounding a garbage
dumpster located inf front of the boat house, 21.09 m (62.3 ft) east of center
of door located on the east side of the boathouse, 17.80  m (58.4 ft) NW of the
fire hydrant, 4.51 m (14.8 ft) south of the nost westerly of two 1.83 m (6 ft)
diameter concrete stumps, and 0.91 m (3.0 ft) above the driveway.



                         BENCH MARK STAMPING:  5786 D 1995
                         DESIGNATION:          851 5786 D

MONUMENTATION:           Tidal Station disk                    VM#:        16823
AGENCY:                  National Ocean Service (NOS)          IDB PID#:        
SETTING CLASSIFICATION:  Steps                                 OPUS PID#: BBDC07
LATITUDE:   40° 57.2' N (  40.95330)          LONGITUDE:  73° 23.8' W ( -73.39670)


The bench mark is a disk set in concrete steps leading up to the Coast Guard
main office, 24.99 m (82.0 ft) NW of the flagpole,  21.00 m (68.9 ft) north of
the fire hydrant, and 7.01 m (23.0 ft) east of the centerline of the road.  

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  3 of  5

                                                                                
Station ID: 8515786                         PUBLICATION DATE:  11/10/2010
Name:       EATONS NECK, HUNTINGTON BAY                       
            NY
NOAA Chart: 11365                           Latitude:   40° 57.2' N (  40.95330)
USGS Quad:  LLOYD HARBOR                    Longitude:  73° 24.0' W ( -73.40000)


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


                         BENCH MARK STAMPING:  NO 6 1960
                         DESIGNATION:          851 5786 TIDAL 6

MONUMENTATION:           Tidal Station disk                    VM#:        16824
AGENCY:                  US Coast and Geodetic Survey
                         (USC&GS)                              IDB PID#:        
SETTING CLASSIFICATION:  Steps                                 OPUS PID:        
LATITUDE:   40° 57.2' N (  40.95330)          LONGITUDE:  73° 23.8' W ( -73.39670)


The bench mark is a disk set in the steps leading to the motor pool located in
front of the Coast Guard main office, 10.21 m (33.5 ft) NE of the centerline of
the road leading to the Coast Guard docks, and 9.14  m (30.0 ft) south of the
entrance to the Coast Guard Office.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  4 of  5

                                                                                
Station ID: 8515786                         PUBLICATION DATE:  11/10/2010
Name:       EATONS NECK, HUNTINGTON BAY                       
            NY
NOAA Chart: 11365                           Latitude:   40° 57.2' N (  40.95330)
USGS Quad:  LLOYD HARBOR                    Longitude:  73° 24.0' W ( -73.40000)


                            T I D A L   D A T U M S 


Tidal datums at EATONS NECK, HUNTINGTON BAY based on:

     LENGTH OF SERIES:      3 YEARS
     TIME PERIOD:           May 2004 - April 2007
     TIDAL EPOCH:           1983-2001
     CONTROL TIDE STATION:  8467150 BRIDGEPORT, BRIDGEPORT HARBOR


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

     HIGHEST OBSERVED WATER LEVEL (04/16/2007)         =  3.334
     MEAN HIGHER HIGH WATER                     MHHW   =  2.358
     MEAN HIGH WATER                            MHW    =  2.252
     MEAN SEA LEVEL                             MSL    =  1.165
     MEAN TIDE LEVEL                            MTL    =  1.162
     MEAN LOW WATER                             MLW    =  0.073
     MEAN LOWER LOW WATER                       MLLW   =  0.000
     LOWEST  OBSERVED WATER LEVEL (03/09/2005)         = -0.927

North American Vertical Datum (NAVD88)

Bench Mark Elevation Information                In METERS above:

     Stamping or Designation                    MLLW        MHW

     5786 A 1995                                 3.526    1.274
     5786 B 1995                                 3.626    1.374
     5786 C 1995                                 5.725    3.473
     5786 D 1995                                11.654    9.402
     NO 6 1960                                  15.761   13.509


                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  5 of  5

                                                                                
Station ID: 8515786                         PUBLICATION DATE:  11/10/2010
Name:       EATONS NECK, HUNTINGTON BAY                       
            NY
NOAA Chart: 11365                           Latitude:   40° 57.2' N (  40.95330)
USGS Quad:  LLOYD HARBOR                    Longitude:  73° 24.0' W ( -73.40000)


                             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.