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

                                                                                
Station ID: 8512668                         PUBLICATION DATE:  06/13/2013
Name:       MATTITUCK INLET, LONG ISLAND                      
            NY
NOAA Chart: 12358                           Latitude:   41°  0.9' N (  41.01500)
USGS Quad:  MATTITUCK HILLS                 Longitude:  72° 33.7' W ( -72.56170)


To reach the tidal bench marks from the post office in Mattituck, NY, head west
on US 25 (Sound Avenue) for 1.6 km (1.0 mi), turn right onto Cox Neck Road for
1.3 km (0.8 mi), and follow for 1.6 km (1.0 mi), and turn left onto Naugles Road
after 0.5 km (0.3 mi). The benchmarks are along Naugles Road and along the
access road for the Mattituck Creek waterway access site.


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


                 PRIMARY BENCH MARK STAMPING:  2668 A 2003
                         DESIGNATION:          851 2668 A

MONUMENTATION:           Tidal Station disk                    VM#:        17589
AGENCY:                  National Ocean Service (NOS)          IDB PID#:        
SETTING CLASSIFICATION:  Stainless steel rod                   OPUS PID#: BBCZ71
LATITUDE:   41°  0.8' N (  41.01379)          LONGITUDE:  72° 33.2' W ( -72.55297)


The primary bench mark is located at the southwest end of the intersection of
Breakwater and Naugles road, 24.3 m (79.7 ft) east of a retaining wall
constructed from railroad ties, 8.4 m (27.6 ft) south of the centerline of
Naugles road, 5.8 m (19.0 ft) southwest of a wood and wire fence, and 2.9 m (9.5
ft) southeast of utility pole 23.  The mark is a stainless steel rod driven to
an unspecified depth.The sleeve depth does not meet the requirements for a Class
A rod mark.

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

                                                                                
Station ID: 8512668                         PUBLICATION DATE:  06/13/2013
Name:       MATTITUCK INLET, LONG ISLAND                      
            NY
NOAA Chart: 12358                           Latitude:   41°  0.9' N (  41.01500)
USGS Quad:  MATTITUCK HILLS                 Longitude:  72° 33.7' W ( -72.56170)


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


                         BENCH MARK STAMPING:  2668 B 2013
                         DESIGNATION:          851 2668 B

MONUMENTATION:           Tidal Station disk                    VM#:        20675
AGENCY:                  National Ocean Service (NOS)          IDB PID#:        
SETTING CLASSIFICATION:  Concrete pad                          OPUS PID#: BBDB79
LATITUDE:   41°  0.8' N (  41.01350)          LONGITUDE:  72° 33.2' W ( -72.55261)


The bench mark is a brass disk set in a concrete pad between two boat launching
ramps 10.17 m (33.4 ft) SE of a small boulder with a dedication plaque on it,
9.24 m (30.3 ft) SE of the northeastern most dock light, 6.35 m (20.8 ft) NW of
the fourth cyclone fence pipe from a gate leading into a boatyard, and 6.33 m
(20.8 ft) NE of the NW of two 5x5 gray composite posts.



                         BENCH MARK STAMPING:  2668 C 2013
                         DESIGNATION:          851 2668 C

MONUMENTATION:           Tidal Station disk                    VM#:        20676
AGENCY:                  National Ocean Service (NOS)          IDB PID#:        
SETTING CLASSIFICATION:  Boulder                               OPUS PID:        
LATITUDE:   41°  0.8' N (  41.01300)          LONGITUDE:  72° 33.2' W ( -72.55311)


The bench mark is set into a large boulder measuring 3 m (9.8 ft) by 1.5 m (4.9
ft) by 1.2 m (3.9 ft), 29.05 m (95.3 ft) west of the second southernmost cyclone
fence pipe at the nearby boat yard, 26.68 m (87.5 ft) south of a directional
sign on two posts, 14.25 m (46.8 ft) east of a 4 inch (10 cm) property corner
pile, and 9.80 m (32.2 ft) SW of the edge of a red brick paved area.

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

                                                                                
Station ID: 8512668                         PUBLICATION DATE:  06/13/2013
Name:       MATTITUCK INLET, LONG ISLAND                      
            NY
NOAA Chart: 12358                           Latitude:   41°  0.9' N (  41.01500)
USGS Quad:  MATTITUCK HILLS                 Longitude:  72° 33.7' W ( -72.56170)


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


                         BENCH MARK STAMPING:  2668 D 2013
                         DESIGNATION:          851 2668 D

MONUMENTATION:           Tidal Station disk                    VM#:        20677
AGENCY:                  National Ocean Service (NOS)          IDB PID#:        
SETTING CLASSIFICATION:  Concrete pad                          OPUS PID:        
LATITUDE:   41°  0.8' N (  41.01331)          LONGITUDE:  72° 33.2' W ( -72.55389)


The bench mark is set into a fenced pad containing two portable toilets enclosed
by an 8 ft (2.4 m) composite fence, 12.14 m (39.8 ft)NW of the eastern corner of
the edge of the intersection of a walkway and the main site access road, 8.53 m
(28.0 ft) SW of a walking path light, 5.0 m (16.4 ft) west of the westernmost of
three 5 inch (13 cm) by 5 inch (13 cm) composite posts, and 4.81 m (15.8 ft) SE
of an information board.



                         BENCH MARK STAMPING:  2668 E 2013
                         DESIGNATION:          851 2668 E

MONUMENTATION:           Tidal Station disk                    VM#:        20678
AGENCY:                  National Ocean Service (NOS)          IDB PID#:        
SETTING CLASSIFICATION:  Concrete pad                          OPUS PID:        
LATITUDE:   41°  0.7' N (  41.01211)          LONGITUDE:  72° 33.4' W ( -72.55639)


The bench mark is set in a concrete pad containing a single portable toilet
surrounded by an 8 ft (2.4 m) composite fence near the entrance to the site,
14.40 m (47.2 ft) NE of the centerline of the site access road, 14.21 m (46.6
ft) south of the westernmost of two benches, 7.63 m (25.0 ft) south of an
information sign containing a cork board, and 3.34 m (11.0 ft) north of a bike
rack.

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

                                                                                
Station ID: 8512668                         PUBLICATION DATE:  06/13/2013
Name:       MATTITUCK INLET, LONG ISLAND                      
            NY
NOAA Chart: 12358                           Latitude:   41°  0.9' N (  41.01500)
USGS Quad:  MATTITUCK HILLS                 Longitude:  72° 33.7' W ( -72.56170)


                            T I D A L   D A T U M S 


Tidal datums at MATTITUCK INLET, LONG ISLAND based on:

     LENGTH OF SERIES:      30 DAYS
     TIME PERIOD:           March 24 2013 - April 22 2013
     TIDAL EPOCH:           1983-2001
     CONTROL TIDE STATION:  8467150 BRIDGEPORT, BRIDGEPORT HARBOR


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

     MEAN HIGHER HIGH WATER                     MHHW   =  1.700
     MEAN HIGH WATER                            MHW    =  1.611
     MEAN TIDE LEVEL                            MTL    =  0.837
     MEAN SEA LEVEL                             MSL    =  0.828
     MEAN LOW WATER                             MLW    =  0.063
     MEAN LOWER LOW WATER                       MLLW   =  0.000

North American Vertical Datum (NAVD88)

Bench Mark Elevation Information                In METERS above:

     Stamping or Designation                    MLLW        MHW

     2668 A 2003                                 3.966    2.355
     2668 B 2013                                 2.414    0.803
     2668 C 2013                                 3.531    1.920
     2668 D 2013                                 2.445    0.834
     2668 E 2013                                 3.039    1.428


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

                                                                                
Station ID: 8512668                         PUBLICATION DATE:  06/13/2013
Name:       MATTITUCK INLET, LONG ISLAND                      
            NY
NOAA Chart: 12358                           Latitude:   41°  0.9' N (  41.01500)
USGS Quad:  MATTITUCK HILLS                 Longitude:  72° 33.7' W ( -72.56170)


                             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.