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

                                                                                
Station ID: 8519436                         PUBLICATION DATE:  12/04/2014
Name:       GREAT KILLS HARBOR                                
            NY
NOAA Chart: 12331                           Latitude:   40° 32.6' N (  40.54330)
USGS Quad:  ARTHUR KILL                     Longitude:  74°  8.4' W ( -74.14000)


To reach the tide station from the toll station at the W end of the Verrazano
Narrows bridge, proceed 0.3 km (0.2 mi) W on i-278 to exit 15S on the right for
lily pond avenue S, proceed 0.25 km (0.15 mi) around the exit ramp onto S Lily
Pond Avenue, continue 0.9 km (0.6 mi) SE on Lily Pond Avenue to the sharp bend
to the right, continue S and then SW 3.8 km (2.4 mi) on Father Capodanno
Boulevard to Midland Avenue, turn right onto Midland Avenue and proceed NE 1.3
km (0.8 mi) to Hylan Boulevard, turn left and proceed 5.3 km (3.3 mi) SW on
Hylan Boulevard to Cleveland Avenue, turn left and proceed SE 0.2 km (0.1 mi) on
Cleveland Avenue to Mansion Avenue, turn left and proceed 0.3 km (0.2 mi) NE on
Mansion Avenue to the gated entrance to the Richmond county yacht club on the
right and the tide station at the end of the wooden dock.  The bench marks are
along Mansion Avenue and in the national park service gateway national
recreation area at Great Kills Park.


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


                 PRIMARY BENCH MARK STAMPING:  9436 D 2014
                         DESIGNATION:          851 9436 D

MONUMENTATION:           Flange-encased Rod                    VM#:        21080
AGENCY:                  National Ocean Service                IDB PID#:        
SETTING CLASSIFICATION:  Stainless steel rod in sleeve         OPUS PID:        
LATITUDE:   40° 32.8' N (  40.54628)          LONGITUDE:  74°  7.8' W ( -74.13058)


The primary bench mark is a flange encased rod set in the grass between the
gravel road and the shore, 35.55 m (116.6 ft) W of the bulkhead road street
sign, 13.68 m (44.9 ft) S of the centerline of the gravel road, 8.70 m (28.5 ft)
NE of the wooden bulkhead and 1.32 m (4.3 ft) SW of a wooden piling along the
edge of the gravel road.

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

                                                                                
Station ID: 8519436                         PUBLICATION DATE:  12/04/2014
Name:       GREAT KILLS HARBOR                                
            NY
NOAA Chart: 12331                           Latitude:   40° 32.6' N (  40.54330)
USGS Quad:  ARTHUR KILL                     Longitude:  74°  8.4' W ( -74.14000)


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


                         BENCH MARK STAMPING:  9436 B 2014
                         DESIGNATION:          851 9436 B

MONUMENTATION:           Bench Mark disk                       VM#:        21081
AGENCY:                  National Ocean Service                IDB PID#:        
SETTING CLASSIFICATION:  Concrete island                       OPUS PID:        
LATITUDE:   40° 32.7' N (  40.54444)          LONGITUDE:  74°  8.4' W ( -74.14061)


The bench mark is a disk set in the NW end of the concrete island for the
automatic gate to the Richmond county yacht club parking lot, 45.42 m (149.0 ft)
NNW of the most N corner of the bulkhead, 28.28 m (92.8 ft) SE of the SE corner
of the marina grand restaurant, 11.85 m (38.9 ft) SE of the centerline of
mansion avenue and 3.52 m (11.5 ft) NW of the automated entrance gate.



                         BENCH MARK STAMPING:  9436 A 2014
                         DESIGNATION:          851 9436 A

MONUMENTATION:           Bench Mark disk                       VM#:        21082
AGENCY:                  National Ocean Service                IDB PID#:        
SETTING CLASSIFICATION:  Footing of a garage door              OPUS PID:        
LATITUDE:   40° 32.6' N (  40.54297)          LONGITUDE:  74°  8.5' W ( -74.14175)


The bench mark is a disk set in a garage door sill on the N side of the Staten
Island yacht sales building, 22.60 m (74.1 ft) S of the SE corner of the one
story building to the N along mansion avenue, 14.48 m (47.5 ft) ESE of the NW
corner of the building, 6.62 m (21.7 ft) WNW of the NE corner of the building
and 0.15 m (0.5 ft) WNW of the E side of the garage door.

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

                                                                                
Station ID: 8519436                         PUBLICATION DATE:  12/04/2014
Name:       GREAT KILLS HARBOR                                
            NY
NOAA Chart: 12331                           Latitude:   40° 32.6' N (  40.54330)
USGS Quad:  ARTHUR KILL                     Longitude:  74°  8.4' W ( -74.14000)


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


                         BENCH MARK STAMPING:  9436 C 2014
                         DESIGNATION:          851 9436 C

MONUMENTATION:           Bench Mark disk                       VM#:        21083
AGENCY:                  National Ocean Service                IDB PID#:        
SETTING CLASSIFICATION:  Concrete flagpole base                OPUS PID:        
LATITUDE:   40° 32.8' N (  40.54589)          LONGITUDE:  74°  8.2' W ( -74.13728)


The bench mark is a disk set in a concrete base for a flagpole, 27.91 m (91.6
ft) S of a power pole near the fence along the NE side of the boat yard, 17.60 m
(57.7 ft) ESE of a light pole in the boat yard, 16.47 m (54.0 ft) S of the NW
corner of the concrete pad for the travel lift, 9.58 m (31.4 ft) NNW of the
bulkhead and 14 cm (6 inches) above grade.



                         BENCH MARK STAMPING:  9436 E 2014
                         DESIGNATION:          851 9436 E

MONUMENTATION:           Flange-encased Rod                    VM#:        21084
AGENCY:                  National Ocean Service                IDB PID#:        
SETTING CLASSIFICATION:  Stainless steel rod in sleeve         OPUS PID#: BBDM38
LATITUDE:   40° 32.7' N (  40.54494)          LONGITUDE:  74°  7.6' W ( -74.12728)


The bench mark is a flange encased rod set in the grass E of the building, 51.15
m (167.8 ft) SW of the SW corner of a green electrical utility box along the
gravel road, 37.62 m (123.4 ft) SSE of a fire hydrant, 26.17 m (85.9 ft) ENE of
the SE corner of the building, 23.89 m (78.4 ft) SE of the NE corner of the
building and 10.39 m (34.1 ft) WSW of the center of a bench.

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

                                                                                
Station ID: 8519436                         PUBLICATION DATE:  12/04/2014
Name:       GREAT KILLS HARBOR                                
            NY
NOAA Chart: 12331                           Latitude:   40° 32.6' N (  40.54330)
USGS Quad:  ARTHUR KILL                     Longitude:  74°  8.4' W ( -74.14000)


                            T I D A L   D A T U M S 


Tidal datums at GREAT KILLS HARBOR based on:

     LENGTH OF SERIES:      3 MONTHS
     TIME PERIOD:           May 2014 - July 2014
     TIDAL EPOCH:           1983-2001
     CONTROL TIDE STATION:  8531680 SANDY HOOK


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

     MEAN HIGHER HIGH WATER                     MHHW   =  1.666
     MEAN HIGH WATER                            MHW    =  1.564
     MEAN SEA LEVEL                             MSL    =  0.832
     MEAN TIDE LEVEL                            MTL    =  0.815
     MEAN LOW WATER                             MLW    =  0.066
     MEAN LOWER LOW WATER                       MLLW   =  0.000

North American Vertical Datum (NAVD88)

Bench Mark Elevation Information                In METERS above:

     Stamping or Designation                    MLLW        MHW

     9436 D 2014                                 3.749    2.185
     9436 B 2014                                 2.734    1.170
     9436 A 2014                                 3.226    1.662
     9436 C 2014                                 3.419    1.855
     9436 E 2014                                 6.554    4.990


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

                                                                                
Station ID: 8519436                         PUBLICATION DATE:  12/04/2014
Name:       GREAT KILLS HARBOR                                
            NY
NOAA Chart: 12331                           Latitude:   40° 32.6' N (  40.54330)
USGS Quad:  ARTHUR KILL                     Longitude:  74°  8.4' W ( -74.14000)


                             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.