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

                                                   PUBLICATION DATE:  03/19/1986
Station ID: 8519024                                SUPERCEDED DATE:   04/21/2003
Name:       FORT WADSWORTH, STATEN ISLAND                     
            NEW YORK
NOAA Chart: 12334                                  Latitude:         40° 36.4' N
USGS Quad:  THE NARROWS                            Longitude:        74°  3.3' W


To reach the tidal bench marks located at Fort Wadsworth, Staten Island, proceed
off the last exit of Interstate I-278 before crossing the Verrazano Narrows
Bridge into Brooklyn, then along Wadsworth Street to the park and a service road
and through the gate down to the pier.  The bench marks are located in top of a
granite block seawall in the vicinity of Ft. Wadsworth.  The tide gage and staff
were located on the NW side of the pier.


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


                 PRIMARY BENCH MARK STAMPING:  NO 3 1951

MONUMENTATION:           Survey Disk                               VM#:     2406
AGENCY:                                                            PID#:  KV0403
SETTING CLASSIFICATION:  Granite Block Seawall


The bench mark is set in top of a granite block seawall, SE of the pier at Ft.
Wadsworth, 147 feet (45 m) SE of Bench Mark 9024 A 1980, 119 feet (36 m) NW of
north corner of abandoned fortification called Fort Weed, 90 feet (27 m) east of
the centerline of the pier, 32 feet (10 m) north of centerline of service road,
and 7 feet (2 m) above shoreline.



                         BENCH MARK STAMPING:  NO 2 1951

MONUMENTATION:           Survey Disk                               VM#:     2405
AGENCY:                                                            PID#:  KV0406
SETTING CLASSIFICATION:  Concrete Seawall


The bench mark is set in top of the SE end of a concrete seawall west of the
pier at Ft. Wadsworth, at the junction of the granite block seawall and concrete
seawall, 142 feet (43 m) SW of Bench Mark 9024 A 1980, 25 feet (8 m) west of a
small concrete block building, formerly housing switchboard, and 8 feet (2 m)
above shoreline.

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

                                                   PUBLICATION DATE:  03/19/1986
Station ID: 8519024                                SUPERCEDED DATE:   04/21/2003
Name:       FORT WADSWORTH, STATEN ISLAND                     
            NEW YORK
NOAA Chart: 12334                                  Latitude:         40° 36.4' N
USGS Quad:  THE NARROWS                            Longitude:        74°  3.3' W


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


                         BENCH MARK STAMPING:  NO 5 1951

MONUMENTATION:           Survey Disk                               VM#:     2407
AGENCY:                                                            PID#:  KV0398
SETTING CLASSIFICATION:  Concrete Wall


The bench mark is set in top of inner one of two concentric concrete walls
forming tank about 2 feet (0.6 m) deep, 300 feet (91 m) SE of NW corner of Old
Fort, 40 feet (12 m) east and across road from small concrete block building
#79, 40 feet (12 m) SW of Building #E-53, 31 feet (9 m) SE of a fire hydrant,
and 18 feet (5 m) east of centerline of road leading to pier.



                         BENCH MARK STAMPING:  9024 A 1980

MONUMENTATION:           Survey Disk                               VM#:     2408
AGENCY:                                                            PID:         
SETTING CLASSIFICATION:  Concrete Pier


The bench mark is set flush in a concrete section of a granite service pier
located at Ft. Wadsworth, 106 feet (32 m) south of the northermost corner of the
wooden section of the pier, 27 feet (8 m) west of a set of granite steps which
lead into the water from the pier, and 10 feet (3 m) east of the western edge of
the pier, and is east of the easternmost rail of a small set of railroad tracks
on the granite section of the pier.

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

                                                   PUBLICATION DATE:  03/19/1986
Station ID: 8519024                                SUPERCEDED DATE:   04/21/2003
Name:       FORT WADSWORTH, STATEN ISLAND                     
            NEW YORK
NOAA Chart: 12334                                  Latitude:         40° 36.4' N
USGS Quad:  THE NARROWS                            Longitude:        74°  3.3' W


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


                         BENCH MARK STAMPING:  9024 B 1980

MONUMENTATION:           Survey Disk                               VM#:     2409
AGENCY:                                                            PID:         
SETTING CLASSIFICATION:  Concrete Wall


The bench mark is set flush in top of a small concrete wall which is 2.9 feet
(0.9 m) high and the southernmost section of the wall immediately adjacent to a 
small walk/railway entrance to the Fort, 45 feet (14 m) east of the centerline
of the road, 36 feet (11 m) north of the centerline of a set of railroad tracks
leading into the Fort Entrance, and 27 feet (8 m) west from the Fort wall in the
NW corner of the square formed by the Fort and the small U shaped wall.

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

                                                   PUBLICATION DATE:  03/19/1986
Station ID: 8519024                                SUPERCEDED DATE:   04/21/2003
Name:       FORT WADSWORTH, STATEN ISLAND                     
            NEW YORK
NOAA Chart: 12334                                  Latitude:         40° 36.4' N
USGS Quad:  THE NARROWS                            Longitude:        74°  3.3' W


                            T I D A L   D A T U M S 


Tidal datums at FORT WADSWORTH, STATEN ISLAND based on:

     LENGTH OF SERIES:      3 MONTHS
     TIME PERIOD:           AUGUST - OCTOBER 1980
     TIDAL EPOCH:           1960-1978
     CONTROL TIDE STATION:  8518750 THE BATTERY


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

     HIGHEST OBSERVED WATER LEVEL (10/25/1980)         =   7.93
     MEAN HIGHER HIGH WATER                     MHHW   =   5.10
     MEAN HIGH WATER                            MHW    =   4.76
     MEAN TIDE LEVEL                            MTL    =   2.49
   * NATIONAL GEODETIC VERTICAL DATUM           NGVD29 =   1.79
     MEAN LOW WATER                             MLW    =   0.21
     MEAN LOWER LOW WATER                       MLLW   =   0.00
     LOWEST  OBSERVED WATER LEVEL (10/26/1980)         =  -2.71

   * NGVD reference based on elevations published in Quad *NGVD is, 1968, and
     NOS leveling of 1981. 
North American Vertical Datum (NAVD88)

Bench Mark Elevation Information                In FEET above:

     Stamping or Designation                    MLLW        MHW

     NO 3 1951                                   8.94      4.18
     NO 2 1951                                  14.86     10.10
     NO 5 1951                                  14.06      9.30
     9024 A 1980                                10.76      6.00
     9024 B 1980                                13.91      9.15


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

                                                   PUBLICATION DATE:  03/19/1986
Station ID: 8519024                                SUPERCEDED DATE:   04/21/2003
Name:       FORT WADSWORTH, STATEN ISLAND                     
            NEW YORK
NOAA Chart: 12334                                  Latitude:         40° 36.4' N
USGS Quad:  THE NARROWS                            Longitude:        74°  3.3' 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.