U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
Datums Page                                                        Page  1 of  6

                                                                                
Station ID: 8518639                         PUBLICATION DATE:  06/28/2004
Name:       PORT MORRIS, EAST 138TH ST.                       
            NY
NOAA Chart: 12339                           Latitude:   40° 48.1' N (  40.80170)
USGS Quad:  CENTRAL PARK                    Longitude:  73° 54.4' W ( -73.90670)


To reach the tidal bench marks from FDR Drive in Manhattan, take the Willis
Avenue Bridge exit and follow Willis Avenue north to 138th Street, turn right
(east) onto 138th Street and continue to its end at East River.  The bench marks
are on the property of Castle Terminals, Inc. on the left (north) side of the
road at the river.  The tide gage was located on the NE side of the steel
catwalk leading to three loading cells.


                         T I D A L   B E N C H   M A R K S
                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  2 of  6

                                                                                
Station ID: 8518639                         PUBLICATION DATE:  06/28/2004
Name:       PORT MORRIS, EAST 138TH ST.                       
            NY
NOAA Chart: 12339                           Latitude:   40° 48.1' N (  40.80170)
USGS Quad:  CENTRAL PARK                    Longitude:  73° 54.4' W ( -73.90670)


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


                 PRIMARY BENCH MARK STAMPING:  NO 5 1951
                         DESIGNATION:          TIDAL 5 STA I 40 A

MONUMENTATION:           Tidal Station disk                    VM#:         2364
AGENCY:                  US Coast and Geodetic Survey
                         (USC&GS)                              IDB PID#:  KU1012
SETTING CLASSIFICATION:  Concrete retaining wall               OPUS PID:        
LATITUDE:   40° 48.1' N (  40.80170)          LONGITUDE:  73° 54.3' W ( -73.90500)


The primary bench mark is a disk set flush on top of a low, short, north-south
concrete retaining wall, 22 m (72 ft) west of bench mark NO 4 1951, 18 m (59 ft)
NE of the NE curb of East 138th Street, 1.07 m (3.5 ft) NE of the north corner
of the boiler room at Pittston Petroleum Company, 1 m (2 ft) SW of a concrete
retaining wall, and 0.61 m (2.0 ft) above the concrete walk.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  3 of  6

                                                                                
Station ID: 8518639                         PUBLICATION DATE:  06/28/2004
Name:       PORT MORRIS, EAST 138TH ST.                       
            NY
NOAA Chart: 12339                           Latitude:   40° 48.1' N (  40.80170)
USGS Quad:  CENTRAL PARK                    Longitude:  73° 54.4' W ( -73.90670)


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


                         BENCH MARK STAMPING:  NO 4 1951
                         DESIGNATION:          TIDAL 4 STA I 40 A

MONUMENTATION:           Tidal Station disk                    VM#:         2363
AGENCY:                  US Coast and Geodetic Survey
                         (USC&GS)                              IDB PID#:  KU1013
SETTING CLASSIFICATION:  Concrete retaining wall               OPUS PID:        
LATITUDE:   40° 48.1' N (  40.80170)          LONGITUDE:  73° 54.3' W ( -73.90500)


The bench mark is a disk set flush on top of a low, short, north-south concrete
retaining wall, 23.62 m (77.5 ft) NW of a bulkhead, 15.85 m (52.0 ft) NE of the
NE curb of East 138th Street, 10 m (33 ft) NW of the center of a gate in a woven
wire fence, 2 m (8 ft) SW of a concrete retaining wall, 2 m (7 ft) NE of the NE
corner of the boiler room at Pittston Petroleum Company, and 0.61 m (2.0 ft)
above ground level.



                         BENCH MARK STAMPING:  8639 B 1981
                         DESIGNATION:          851 8639 B

MONUMENTATION:           Tidal Station disk                    VM#:         2366
AGENCY:                  National Ocean Survey (NOS)           IDB PID#:        
SETTING CLASSIFICATION:  Concrete walk                         OPUS PID:        
LATITUDE:   40° 48.1' N (  40.80170)          LONGITUDE:  73° 54.3' W ( -73.90500)


The bench mark is a disk set flush in a concrete walk between a high retaining
wall and the office building at 939 East 138th Street, 18 m (59 ft) west of
bench mark NO 5 1951, 16.31 m (53.5 ft) north of the north curb of 138th Street,
2.19 m (7.2 ft) south of the retaining wall, 1.16 m (3.8 ft) WNW of the NW
corner of the office building, and 0.21 m (0.7 ft) above ground level.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  4 of  6

                                                                                
Station ID: 8518639                         PUBLICATION DATE:  06/28/2004
Name:       PORT MORRIS, EAST 138TH ST.                       
            NY
NOAA Chart: 12339                           Latitude:   40° 48.1' N (  40.80170)
USGS Quad:  CENTRAL PARK                    Longitude:  73° 54.4' W ( -73.90670)


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


                         BENCH MARK STAMPING:  8639 C 1981
                         DESIGNATION:          851 8639 C

MONUMENTATION:           Tidal Station disk                    VM#:         2367
AGENCY:                  National Ocean Survey (NOS)           IDB PID#:        
SETTING CLASSIFICATION:  Concrete doorway inset                OPUS PID:        
LATITUDE:   40° 48.1' N (  40.80170)          LONGITUDE:  73° 54.3' W ( -73.90500)


The bench mark is a disk set flush in a concrete doorway inset in the boiler
room building at Pittston Petroleum Company, 22 m (72 ft) east of the SW end of
the boiler room building, 10.79 m (35.4 ft) NW of the east curb on the north
side of East 138th Street, 7.77 m (25.5 ft) north of the north curb of East
138th Street, and 3.72 m (12.2 ft) west of the SE corner of the boiler room
building.



                         BENCH MARK STAMPING:  8639 D 2000
                         DESIGNATION:          851 8639 D

MONUMENTATION:           Tidal Station disk                    VM#:        16238
AGENCY:                  National Ocean Survey (NOS)           IDB PID#:        
SETTING CLASSIFICATION:  Concrete sheetpile                    OPUS PID:        
LATITUDE:   40° 48.1' N (  40.80170)          LONGITUDE:  73° 54.3' W ( -73.90500)


The bench mark is a disk set in concrete sheetpile cell at the intersection of
138th Street at East River, 20.33 m (66.7 ft) SSE of the shore end of the
catwalk leading to the cell, 8.51 m (27.9 ft) north of the ballard on the
southern side of the cell, 3.55 m (11.7 ft) east of the south offshore corner of
the catwalk leading to the cell, and 2.24 m (7.3 ft) south of the SE offshore
end of the catwalk leading to the cell.  

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  5 of  6

                                                                                
Station ID: 8518639                         PUBLICATION DATE:  06/28/2004
Name:       PORT MORRIS, EAST 138TH ST.                       
            NY
NOAA Chart: 12339                           Latitude:   40° 48.1' N (  40.80170)
USGS Quad:  CENTRAL PARK                    Longitude:  73° 54.4' W ( -73.90670)


                            T I D A L   D A T U M S 


Tidal datums at PORT MORRIS, EAST 138TH ST. based on:

     LENGTH OF SERIES:      1 YEAR
     TIME PERIOD:           August 2000 - July 2001
     TIDAL EPOCH:           1983-2001
     CONTROL TIDE STATION:  8516945 KINGS POINT, LONG ISLAND SOUND


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

     HIGHEST OBSERVED WATER LEVEL (03/07/2001)         =  2.785
     MEAN HIGHER HIGH WATER                     MHHW   =  2.089
     MEAN HIGH WATER                            MHW    =  1.982
     North American Vertical Datum              NAVD88 =  1.073
     MEAN TIDE LEVEL                            MTL    =  1.032
     MEAN SEA LEVEL                             MSL    =  1.030
     MEAN LOW WATER                             MLW    =  0.081
     MEAN LOWER LOW WATER                       MLLW   =  0.000
     LOWEST  OBSERVED WATER LEVEL (12/13/2000)         = -0.907

North American Vertical Datum (NAVD88)

Bench Mark Elevation Information                In METERS above:

     Stamping or Designation                    MLLW        MHW

     NO 5 1951                                   4.749    2.767
     NO 4 1951                                   4.645    2.663
     8639 B 1981                                 4.325    2.343
     8639 C 1981                                 4.119    2.137
     8639 D 2000                                 3.606    1.624


                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  6 of  6

                                                                                
Station ID: 8518639                         PUBLICATION DATE:  06/28/2004
Name:       PORT MORRIS, EAST 138TH ST.                       
            NY
NOAA Chart: 12339                           Latitude:   40° 48.1' N (  40.80170)
USGS Quad:  CENTRAL PARK                    Longitude:  73° 54.4' W ( -73.90670)


                             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.