U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
Datums Page                                                        Page  1 of 10

                                                                                
Station ID: 8531680                         PUBLICATION DATE:  04/21/2003
Name:       SANDY HOOK                                        
            NJ
NOAA Chart: 12327                           Latitude:   40° 28.0' N (  40.46670)
USGS Quad:  SANDY HOOK                      Longitude:  74°  0.6' W ( -74.01000)


To reach the tidal bench marks from the Garden State Parkway, north or south,
follow lanes marked Local/All Exits, exit 117 - State Highway 36 east for 22.0
km (13.7 mi) to the bridge at Atlantic Highlands.  Follow signs to Gateway NRA,
Sandy Hook, pass toll booths, and then Ocean Road north for 9.2 km (5.7 mi) to
U.S. Coast Guard Base Fort Hancock.  The bench marks are scattered around the
Coast Guard Station, and the gage is located at the south end of U.S.C.G small
pier in a tide house with NOS sign.


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


                 PRIMARY BENCH MARK STAMPING:  1680 A 1979
                         DESIGNATION:          853 1680 A TIDAL

MONUMENTATION:           Tidal Station disk                    VM#:          317
AGENCY:                  National Ocean Survey (NOS)           IDB PID#:  KV3519
SETTING CLASSIFICATION:  Stainless steel rod                   OPUS PID:        
LATITUDE:   40° 28.1' N (  40.46830)          LONGITUDE:  74°  0.4' W ( -74.00670)


The primary bench mark is a disk located at the SE corner of a metal garage,
91.4 m (300 ft) east of the headquarters building, 56.54 m (185.5 ft) north of
the centerline of the road leading to the base, 5.39 m (17.7 ft) south of the
south rail of tracks running through the garage, and 2.26 m (7.4 ft) south of
the SE corner of the garage. The bench mark is crimped to a stainless steel rod
driven 14.6 m (48 ft) to refusal, and encased in a 4 inch PVC pipe with concrete
kickblock.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  2 of 10

                                                                                
Station ID: 8531680                         PUBLICATION DATE:  04/21/2003
Name:       SANDY HOOK                                        
            NJ
NOAA Chart: 12327                           Latitude:   40° 28.0' N (  40.46670)
USGS Quad:  SANDY HOOK                      Longitude:  74°  0.6' W ( -74.01000)


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


                         BENCH MARK STAMPING:  SIMPSON 2 1972
                         DESIGNATION:          SIMPSON 2

MONUMENTATION:           Triangulation Station disk            VM#:          320
AGENCY:                  National Geodetic Survey (NGS)        IDB PID#:  KV0709
SETTING CLASSIFICATION:  Concrete monument                     OPUS PID:        
LATITUDE:   40° 28.1' N (  40.46844)          LONGITUDE:  74°  0.5' W ( -74.00831)


The bench mark is a disk set in a concrete monument, 23.96 m (78.6 ft) east of
the NE corner of the headquarters building, 5.55 m (18.2 ft) south of the SE
corner of a parking lot, 2.70 m (8.9 ft) west of the west curb of Crispin Road,
0.76 m (2.5 ft) SE of a witness post, and is 0.08 m (0.3 ft) below grade.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  3 of 10

                                                                                
Station ID: 8531680                         PUBLICATION DATE:  04/21/2003
Name:       SANDY HOOK                                        
            NJ
NOAA Chart: 12327                           Latitude:   40° 28.0' N (  40.46670)
USGS Quad:  SANDY HOOK                      Longitude:  74°  0.6' W ( -74.01000)


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


                         BENCH MARK STAMPING:  SIMPSON 2 NO 3 1972
                         DESIGNATION:          SIMPSON 2 RM 3

MONUMENTATION:           Reference Mark disk                   VM#:          321
AGENCY:                  National Geodetic Survey (NGS)        IDB PID#:  KV0707
SETTING CLASSIFICATION:  Concrete monument                     OPUS PID#: KV0707
LATITUDE:   40° 28.1' N (  40.46839)          LONGITUDE:  74°  0.5' W ( -74.00806)


The bench mark is a disk set in a concrete monument, 41.45 m (136.0 ft) east of
the east wall of the headquarters building, 17.07 m (56.0 ft) east of a fire
hydrant, 9.95 m (32.6 ft) east of the centerline of Crispin Road, and 0.30 m
(1.0 ft) west of a witness post.



                         BENCH MARK STAMPING:  8 1932
                         DESIGNATION:          853 1680 TIDAL 8

MONUMENTATION:           Tidal Station disk                    VM#:          322
AGENCY:                  US Coast and Geodetic Survey
                         (USC&GS)                              IDB PID#:  KV0712
SETTING CLASSIFICATION:  Concrete monument                     OPUS PID:        
LATITUDE:   40° 28.0' N (  40.46667)          LONGITUDE:  74°  0.3' W ( -74.00547)


The bench mark is a disk set in a concrete monument, 8.99 m (29.5 ft) NE of the
NW corner of Building 102, 4.27 m (14.0 ft) NW of steps heading east, 3.20 m
(10.5 ft) east of the east edge of the concrete walk, 3.0 m (10 ft) north of the
NE corner of the north wing of the building, 0.76 m (2.5 ft) north of the north
edge of the concrete walk, and 0.06 m (0.2 ft) above ground.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  4 of 10

                                                                                
Station ID: 8531680                         PUBLICATION DATE:  04/21/2003
Name:       SANDY HOOK                                        
            NJ
NOAA Chart: 12327                           Latitude:   40° 28.0' N (  40.46670)
USGS Quad:  SANDY HOOK                      Longitude:  74°  0.6' W ( -74.01000)


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


                         BENCH MARK STAMPING:  S 80 1979
                         DESIGNATION:          S 80

MONUMENTATION:           Flange-encased Rod                    VM#:          323
AGENCY:                  National Geodetic Survey (NGS)        IDB PID#:  KV3521
SETTING CLASSIFICATION:  Stainless steel rod in sleeve         OPUS PID:        
LATITUDE:   40° 28.1' N (  40.46808)          LONGITUDE:  74°  0.5' W ( -74.00844)


The bench mark is located at the east corner of the headquarters building, 35.1
m (115 ft) NW of the NW curb of Canfield Road, 29.78 m (97.7 ft) SW of the SW
curb of Hartshore Drive, 11.0 m (36 ft) east of the center of the SE double
doors to the building, and 0.61 m (2.0 ft) SE of the east corner of the
building. The datum point is the top of a stainless steel rod driven 9.14 m
(30.0 ft) to refusal, in a sleeve extending to a depth of 3.05 m (10.0 ft), and
encased in a 5 inch NGS logo cap.



                         BENCH MARK STAMPING:  1680 C 1979
                         DESIGNATION:          853 1680 C

MONUMENTATION:           Tidal Station disk                    VM#:          325
AGENCY:                  National Ocean Survey (NOS)           IDB PID#:        
SETTING CLASSIFICATION:  Stainless steel rod                   OPUS PID:        
LATITUDE:   40° 27.9' N (  40.46506)          LONGITUDE:  74°  0.3' W ( -74.00511)


The bench mark is a disk located at the SW corner of the Sandy Hook Fire
Department, 57.97 m (190.2 ft) SE of the large cannon at the entrance of the
base, 6.10 m (20.0 ft) east of the centerline of Kearney Street, and 1.52 m (5.0
ft) SW of the SW corner of the Sandy Hook Fire Department building. The bench
mark is crimped to a stainless steel rod driven 12.8 m (42 ft) to refusal, and
encased in 4 inch PVC pipe with concrete kickblock.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  5 of 10

                                                                                
Station ID: 8531680                         PUBLICATION DATE:  04/21/2003
Name:       SANDY HOOK                                        
            NJ
NOAA Chart: 12327                           Latitude:   40° 28.0' N (  40.46670)
USGS Quad:  SANDY HOOK                      Longitude:  74°  0.6' W ( -74.01000)


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


                         BENCH MARK STAMPING:  1680 D 1980
                         DESIGNATION:          853 1680 D TIDAL

MONUMENTATION:           Tidal Station disk                    VM#:          326
AGENCY:                  National Ocean Survey (NOS)           IDB PID#:  AB6711
SETTING CLASSIFICATION:  Concrete slab                         OPUS PID:        
LATITUDE:   40° 28.1' N (  40.46900)          LONGITUDE:  74°  0.6' W ( -74.00967)


The bench mark is a disk set in the SE corner of a 1.8 m x 1.8 m (6 ft x 6 ft)
concrete manhole slab located SW of the headquarters building near the garage
complex, 22.25 m (73.0 ft) north of the north end of the most westerly pier on
the Coast Guard property, 16.82 m (55.2 ft) SW of the SW corner of the garage,
8.50 m (27.9 ft) NE of a light pole, and 0.3 m (1 ft) above ground.



                         BENCH MARK STAMPING:  1680 E 1990
                         DESIGNATION:          853 1680 E TIDAL

MONUMENTATION:           Tidal Station disk                    VM#:          327
AGENCY:                  National Ocean Service (NOS)          IDB PID#:  AB6710
SETTING CLASSIFICATION:  Concrete slab                         OPUS PID:        
LATITUDE:   40° 28.1' N (  40.46903)          LONGITUDE:  74°  0.5' W ( -74.00881)


The bench mark is a disk set in the 1.8 m x 3.0 m (8 ft x 10 ft) concrete slab
for a bus stop shelter located along the north edge of the parking lot on the
west side of Crispin Road, 39.75 m (130.4 ft) west of the NE corner of parking
lot, 32.10 m (105.3 ft) east of a fire hydrant, 2.47 m (8.1 ft) NNE of the north
edge of the north parking lot, 0.15 m (0.5 ft) NE of the NE corner of the slab,
and 0.15 m (0.5 ft) above the parking lot.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  6 of 10

                                                                                
Station ID: 8531680                         PUBLICATION DATE:  04/21/2003
Name:       SANDY HOOK                                        
            NJ
NOAA Chart: 12327                           Latitude:   40° 28.0' N (  40.46670)
USGS Quad:  SANDY HOOK                      Longitude:  74°  0.6' W ( -74.01000)


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


                         BENCH MARK STAMPING:  1680 F 1990
                         DESIGNATION:          853 1680 F

MONUMENTATION:           Tidal Station disk                    VM#:          328
AGENCY:                  National Ocean Service (NOS)          IDB PID#:        
SETTING CLASSIFICATION:  Stainless steel rod                   OPUS PID:        
LATITUDE:   40° 28.1' N (  40.46833)          LONGITUDE:  74°  0.4' W ( -74.00594)


The bench mark is a disk located east of the intersection of Kearney Street and
Canfield Roads, 46.0 m (151 ft) east of the centerline of the entrance gate to
the base, 20.27 m (66.5 ft) ESE of a fire hydrant, 14.97 m (49.1 ft) south of
the centerline of the road leading to the park service maintenance area, and
0.85 m (2.8 ft) WNW of the west corner post of an eight feet high chain link
fence. The bench mark is 0.09 m (0.3 ft) below ground, crimped to a stainless
steel rod driven 14.6 m (48 ft), and encased in a 4 inch PVC pipe with concrete
kickblock.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  7 of 10

                                                                                
Station ID: 8531680                         PUBLICATION DATE:  04/21/2003
Name:       SANDY HOOK                                        
            NJ
NOAA Chart: 12327                           Latitude:   40° 28.0' N (  40.46670)
USGS Quad:  SANDY HOOK                      Longitude:  74°  0.6' W ( -74.01000)


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


                         BENCH MARK STAMPING:  FORT HANCOCK NO 4 1940
                         DESIGNATION:          FORT HANCOCK RM 4

MONUMENTATION:           Reference Mark disk                   VM#:        15582
AGENCY:                  US Coast and Geodetic Survey
                         (USC&GS)                              IDB PID#:  KV0701
SETTING CLASSIFICATION:  Concrete tower leg foundation         OPUS PID:        
LATITUDE:   40° 28.3' N (  40.47117)          LONGITUDE:  74°  0.7' W ( -74.01197)


At Fort Hancock, at the old abandoned Coast Guard building at the NW end of a
parking lot, the mark is set in the concrete foundation at the NE leg of a steel
tower, and 0.2 m (0.7 ft) above ground.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  8 of 10

                                                                                
Station ID: 8531680                         PUBLICATION DATE:  04/21/2003
Name:       SANDY HOOK                                        
            NJ
NOAA Chart: 12327                           Latitude:   40° 28.0' N (  40.46670)
USGS Quad:  SANDY HOOK                      Longitude:  74°  0.6' W ( -74.01000)


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


                         BENCH MARK STAMPING:   
                         DESIGNATION:          USED

MONUMENTATION:           Bolt                                  VM#:        15584
AGENCY:                                                        IDB PID#:  KV0714
SETTING CLASSIFICATION:  Concrete monument                     OPUS PID:        
LATITUDE:   40° 27.7' N (  40.46139)          LONGITUDE:  74°  0.3' W ( -74.00436)


The bench mark is a bolt set in a concrete monument near the Sandy Hook National
Park headquarters flagpole, 50.51 m (165.7 ft) east of Kessler Avenue, 11.73 m
(38.5 ft) NNE of the flagpole, and 10.70 m (35.1 ft) SSW of the centerline of
Hudson Road.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  9 of 10

                                                                                
Station ID: 8531680                         PUBLICATION DATE:  04/21/2003
Name:       SANDY HOOK                                        
            NJ
NOAA Chart: 12327                           Latitude:   40° 28.0' N (  40.46670)
USGS Quad:  SANDY HOOK                      Longitude:  74°  0.6' W ( -74.01000)


                            T I D A L   D A T U M S 


Tidal datums at SANDY HOOK based on:

     LENGTH OF SERIES:      19 Years
     TIME PERIOD:           January 1983 - December 2001
     TIDAL EPOCH:           1983-2001
     CONTROL TIDE STATION:   


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

     HIGHEST OBSERVED WATER LEVEL (09/12/1960)         =  3.074
     MEAN HIGHER HIGH WATER                     MHHW   =  1.592
     MEAN HIGH WATER                            MHW    =  1.492
     North American Vertical Datum              NAVD88 =  0.858
     MEAN SEA LEVEL                             MSL    =  0.785
     MEAN TIDE LEVEL                            MTL    =  0.775
     MEAN LOW WATER                             MLW    =  0.058
     MEAN LOWER LOW WATER                       MLLW   =  0.000
     LOWEST  OBSERVED WATER LEVEL (02/02/1976)         = -1.437

North American Vertical Datum (NAVD88)

Bench Mark Elevation Information                In METERS above:

     Stamping or Designation                    MLLW        MHW

     1680 A 1979                                 2.812    1.320
     SIMPSON 2 1972                              2.963    1.471
     SIMPSON 2 NO 3 1972                         2.945    1.453
     8 1932                                      4.524    3.032
     S 80 1979                                   3.404    1.912
     1680 C 1979                                 3.268    1.776
     1680 D 1980                                 2.917    1.426
     1680 E 1990                                 3.618    2.126
     1680 F 1990                                 2.653    1.161
     FORT HANCOCK NO 4 1940                      3.808    2.317
     USED                                        2.916    1.424


                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page 10 of 10

                                                                                
Station ID: 8531680                         PUBLICATION DATE:  04/21/2003
Name:       SANDY HOOK                                        
            NJ
NOAA Chart: 12327                           Latitude:   40° 28.0' N (  40.46670)
USGS Quad:  SANDY HOOK                      Longitude:  74°  0.6' W ( -74.01000)


                             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.