U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
Datums Page                                                        Page  1 of  7

                                                                                
Station ID: 8531545                         PUBLICATION DATE:  02/05/2004
Name:       KEYPORT, RARITAN BAY                              
            NJ
NOAA Chart: 12327                           Latitude:   40° 26.4' N (  40.44000)
USGS Quad:  KEYPORT                         Longitude:  74° 11.9' W ( -74.19830)


To reach the tidal bench marks from the intersection of State Highway 36 and
Atlantic Street in the town of Keyport, proceed north on Atlantic Street for 1.4
km (0.9 mi) to First Street, in the vicinity of Keyport Yacht Club on the corner
of First Street and Atlantic Street.  The tide gage and staff were on the NE
corner of the yacht club pier.  The bench marks are in the vicinity of the yacht
club, and at Chingarora Creek.


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


                 PRIMARY BENCH MARK STAMPING:  1545 A 1975
                         DESIGNATION:          853 1545 A TIDAL

MONUMENTATION:           Tidal Station disk                    VM#:         2545
AGENCY:                  National Ocean Survey (NOS)           IDB PID#:        
SETTING CLASSIFICATION:  Copper-clad steel rod                 OPUS PID:        
LATITUDE:   40° 26.4' N (  40.44000)          LONGITUDE:  74° 11.9' W ( -74.19830)


The primary bench mark is a disk located on the Keyport Yacht Club property,
20.54 m (67.4 ft) south of the timber bulkhead along the bay, 6.13 m (20.1 ft)
NE of SE corner of the club's brick building, 4.02 m (13.2 ft) SE of the NE
corner of the same building, and 1.89 m (6.2 ft) SW of the NW corner of a
concrete platform.  The bench mark is 0.06 m (0.2 ft) below the ground, crimped
to the top of a copper-clad steel rod driven 15.2 m (50 ft).

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  2 of  7

                                                                                
Station ID: 8531545                         PUBLICATION DATE:  02/05/2004
Name:       KEYPORT, RARITAN BAY                              
            NJ
NOAA Chart: 12327                           Latitude:   40° 26.4' N (  40.44000)
USGS Quad:  KEYPORT                         Longitude:  74° 11.9' W ( -74.19830)


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


                         BENCH MARK STAMPING:  1545 B 1975
                         DESIGNATION:          853 1545 B TIDAL

MONUMENTATION:           Tidal Station disk                    VM#:         2546
AGENCY:                  National Ocean Survey (NOS)           IDB PID#:  AI8467
SETTING CLASSIFICATION:  Copper-clad steel rod                 OPUS PID:        
LATITUDE:   40° 26.4' N (  40.44000)          LONGITUDE:  74° 11.8' W ( -74.19670)


The bench mark is a disk located in a small park at the north end of Myrtle
Avenue, 11.67 m (38.3 ft) south of wood utility pole # JC 479 KPT, 3.78 m (12.4
ft) south of a flagpole, 2.80 m (9.2 ft) south of the NW corner of a marble war
moument, and 0.91 m (3.0 ft) east of the edge of a concrete curbing surrounding
the flagpole.  The bench mark is set 0.06 m (0.2 ft) below the ground, crimped
to the top of a copper-clad steel rod driven 12.8 m (42 ft) to refusal.



                         BENCH MARK STAMPING:  1545 C 1975
                         DESIGNATION:          853 1545 C TIDAL

MONUMENTATION:           Tidal Station disk                    VM#:         2547
AGENCY:                  National Ocean Survey (NOS)           IDB PID#:  AI8468
SETTING CLASSIFICATION:  Copper-clad steel rod                 OPUS PID:        
LATITUDE:   40° 26.4' N (  40.44000)          LONGITUDE:  74° 11.4' W ( -74.19000)


The bench mark is a disk located near the bridge over Chingarora Creek, 14.20 m
(46.6 ft) SW of the centerline of Walnut Street, 9.42 m (30.9 ft) NW of the
centerline of First Street, 8.60 m (28.2 ft) SW of a hydrant, 7.77 m (25.5 ft)
NE of the SE corner of the one-story brick building of Bridgeview Apartments,
and 5.67 m (18.6 ft) SE of a sewer manhole on the same property.  The bench mark
is set 0.06 m (0.2 ft) below the ground, crimped to the top of a copper-clad
steel rod driven 12.2 m (40 ft) to refusal.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  3 of  7

                                                                                
Station ID: 8531545                         PUBLICATION DATE:  02/05/2004
Name:       KEYPORT, RARITAN BAY                              
            NJ
NOAA Chart: 12327                           Latitude:   40° 26.4' N (  40.44000)
USGS Quad:  KEYPORT                         Longitude:  74° 11.9' W ( -74.19830)


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


                         BENCH MARK STAMPING:  NO 2 1934
                         DESIGNATION:          TIDAL 2 STA 17

MONUMENTATION:           Tidal Station disk                    VM#:         2548
AGENCY:                  National Ocean Survey (NOS)           IDB PID#:  KV0754
SETTING CLASSIFICATION:  Concrete monument                     OPUS PID:        
LATITUDE:   40° 26.3' N (  40.43830)          LONGITUDE:  74° 11.6' W ( -74.19330)


The bench mark is a disk set in the top of a concrete post, located 0.2 km (0.1
mi) north along Myrtle Avenue from the intersection of First Street and Myrtle
Avenue, 12.80 m (42.0 ft) NE of a fire hydrant, 11.58 m (38.0 ft) ENE of power
pole # 189 W, and 0.03 m (0.1 ft) below the ground.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  4 of  7

                                                                                
Station ID: 8531545                         PUBLICATION DATE:  02/05/2004
Name:       KEYPORT, RARITAN BAY                              
            NJ
NOAA Chart: 12327                           Latitude:   40° 26.4' N (  40.44000)
USGS Quad:  KEYPORT                         Longitude:  74° 11.9' W ( -74.19830)


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


                         BENCH MARK STAMPING:  U 53 1961
                         DESIGNATION:          U 53

MONUMENTATION:           Bench Mark disk                       VM#:         2549
AGENCY:                  US Coast & Geodetic Survey
                         (USC&GS)                                 IDB PID#:  KV0756
SETTING CLASSIFICATION:  Pumping station                       OPUS PID:        
LATITUDE:   40° 26.4' N (  40.44000)          LONGITUDE:  74° 11.5' W ( -74.19170)


The bench mark is a disk set in the west face of the SW corner of the Keyport
Water Works Pumping Station, 51 m (166 ft) WSW of bench mark NO 2 1934, 7 m (22
ft) north of the NE corner of a small brick building, and 1.37 m (4.5 ft) above
the ground.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  5 of  7

                                                                                
Station ID: 8531545                         PUBLICATION DATE:  02/05/2004
Name:       KEYPORT, RARITAN BAY                              
            NJ
NOAA Chart: 12327                           Latitude:   40° 26.4' N (  40.44000)
USGS Quad:  KEYPORT                         Longitude:  74° 11.9' W ( -74.19830)


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


                         BENCH MARK STAMPING:  P 36 1965
                         DESIGNATION:          P 36 RESET

MONUMENTATION:           Bench Mark disk                       VM#:         2550
AGENCY:                  US Coast & Geodetic Survey
                         (USC&GS)                                 IDB PID#:  KV0749
SETTING CLASSIFICATION:  Bridge abutment                       OPUS PID:        
LATITUDE:   40° 26.4' N (  40.44000)          LONGITUDE:  74° 11.3' W ( -74.18830)


The bench mark is a disk set in top of the south end of the west abutment of a
bridge over Chingarora Creek, 15.09 m (49.5 ft) east of power pole # 100W, 4.69
m (15.4 ft) south of the centerline of Stone Street, and 0.24 m (0.8 ft) west of
the east edge of the abutment.  

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  6 of  7

                                                                                
Station ID: 8531545                         PUBLICATION DATE:  02/05/2004
Name:       KEYPORT, RARITAN BAY                              
            NJ
NOAA Chart: 12327                           Latitude:   40° 26.4' N (  40.44000)
USGS Quad:  KEYPORT                         Longitude:  74° 11.9' W ( -74.19830)


                            T I D A L   D A T U M S 


Tidal datums at KEYPORT, RARITAN BAY based on:

     LENGTH OF SERIES:      9 MONTHS
     TIME PERIOD:           March 1976 - November 1976
     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   =  1.705
     MEAN HIGH WATER                            MHW    =  1.604
     North American Vertical Datum              NAVD88 =  0.894
     MEAN SEA LEVEL                             MSL    =  0.863
     MEAN TIDE LEVEL                            MTL    =  0.834
     MEAN LOW WATER                             MLW    =  0.065
     MEAN LOWER LOW WATER                       MLLW   =  0.000

North American Vertical Datum (NAVD88)

Bench Mark Elevation Information                In METERS above:

     Stamping or Designation                    MLLW        MHW

     1545 A 1975                                 7.501    5.897
     1545 B 1975                                 5.528    3.924
     1545 C 1975                                 3.213    1.609
     NO 2 1934                                   6.148    4.544
     U 53 1961                                   6.183    4.579
     P 36 1965                                   3.688    2.084


                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  7 of  7

                                                                                
Station ID: 8531545                         PUBLICATION DATE:  02/05/2004
Name:       KEYPORT, RARITAN BAY                              
            NJ
NOAA Chart: 12327                           Latitude:   40° 26.4' N (  40.44000)
USGS Quad:  KEYPORT                         Longitude:  74° 11.9' W ( -74.19830)


                             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.