U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
Datums Page                                                        Page  1 of  4

                                                   PUBLICATION DATE:  09/26/1988
Station ID: 8448376                                SUPERCEDED DATE:   04/21/2003
Name:       CUTTYHUNK POND ENTRANCE, CUTTYHUNK HARBOR         
            MASSACHUSETTS
NOAA Chart: 13230                                  Latitude:         41° 25.5' N
USGS Quad:  CUTTYHUNK                              Longitude:        70° 55.0' W


To reach the tidal bench marks from the U.S. Coast Guard Station at Cuttyhunk
Pond on Cuttyhunk Island, proceed by boat east on the Cuttyhunk Pond entrance
channel to the north jetty.  The bench marks are located in the vicinity of the
west end of the north jetty.  The bench marks are located in the vicinity of the
west end of the north jetty at the SE end of Copicut Neck.  The tide gage and
staff were located near the north jetty light.


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


                 PRIMARY BENCH MARK STAMPING:  8376 D

MONUMENTATION:           Survey Disk                               VM#:     2096
AGENCY:                                                            PID:         
SETTING CLASSIFICATION:  Concrete Jetty


The bench mark is set in the west end of the concrete and rock north jetty at
the entrance to Cuttyhunk Pond (the mark may be periodically covered by sand).



                         BENCH MARK STAMPING:  8376 E

MONUMENTATION:           Survey Disk                               VM#:     2097
AGENCY:                                                            PID:         
SETTING CLASSIFICATION:  Unspecified Steel Rod


The bench mark is 297 feet (91 m) NW (300o) of Bench Mark 8376 D, and next to a
witness post.  The bench mark is crimped to an unspecified steel rod driven 4
feet (1 m).

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  2 of  4

                                                   PUBLICATION DATE:  09/26/1988
Station ID: 8448376                                SUPERCEDED DATE:   04/21/2003
Name:       CUTTYHUNK POND ENTRANCE, CUTTYHUNK HARBOR         
            MASSACHUSETTS
NOAA Chart: 13230                                  Latitude:         41° 25.5' N
USGS Quad:  CUTTYHUNK                              Longitude:        70° 55.0' W


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


                         BENCH MARK STAMPING:  8376 F

MONUMENTATION:           Survey Disk                               VM#:     2098
AGENCY:                                                            PID:         
SETTING CLASSIFICATION:  Unspecified Steel Rod


The bench mark is 224 feet (68 m) NNW (335o) of Bench Mark 8376 E, 50 feet (15
m) SW of a rock beach, and next to a witness post.  The bench mark is crimped to
an unspecified steel rod driven 4 feet (1 m).



                         BENCH MARK STAMPING:  8376 G

MONUMENTATION:           Survey Disk                               VM#:     2099
AGENCY:                                                            PID:         
SETTING CLASSIFICATION:  Unspecified Steel Rod


The bench mark is 167 feet (51 m) SW (225o) of Bench Mark 8376 F, and next to a
witness post.  The bench mark is crimped to an unspecified steel rod driven 4
feet (1 m).



                         BENCH MARK STAMPING:  8376 H

MONUMENTATION:           Survey Disk                               VM#:     2100
AGENCY:                                                            PID:         
SETTING CLASSIFICATION:  Unspecified Steel Rod


The bench mark is 213 feet (65 m) SE (135o) of Bench Mark 8376 G, 30 feet (9 m)
north of the shoreline of the entrance channel, and next to a witness post.  The
bench mark is crimped to an unspecified steel rod driven 4 feet (1 m).

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  3 of  4

                                                   PUBLICATION DATE:  09/26/1988
Station ID: 8448376                                SUPERCEDED DATE:   04/21/2003
Name:       CUTTYHUNK POND ENTRANCE, CUTTYHUNK HARBOR         
            MASSACHUSETTS
NOAA Chart: 13230                                  Latitude:         41° 25.5' N
USGS Quad:  CUTTYHUNK                              Longitude:        70° 55.0' W


                            T I D A L   D A T U M S 


Tidal datums at CUTTYHUNK POND ENTRANCE, CUTTYHUNK HARBOR based on:

     LENGTH OF SERIES:      3 MONTHS
     TIME PERIOD:           AUGUST - OCTOBER 1976
     TIDAL EPOCH:           1960-1978
     CONTROL TIDE STATION:  8452660 NEWPORT, RI


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

     HIGHEST OBSERVED WATER LEVEL (10/21/1976)         =   5.40
     MEAN HIGHER HIGH WATER                     MHHW   =   3.80
     MEAN HIGH WATER                            MHW    =   3.54
     MEAN TIDE LEVEL                            MTL    =   1.83
     MEAN LOW WATER                             MLW    =   0.12
     MEAN LOWER LOW WATER                       MLLW   =   0.00
     LOWEST  OBSERVED WATER LEVEL (10/23/1976)         =  -1.50



Bench Mark Elevation Information                In FEET above:

     Stamping or Designation                    MLLW        MHW

     8376 D                                      6.58      3.04
     8376 E                                      6.60      3.06
     8376 F                                      8.25      4.71
     8376 G                                      7.72      4.18
     8376 H                                      9.19      5.65


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

                                                   PUBLICATION DATE:  09/26/1988
Station ID: 8448376                                SUPERCEDED DATE:   04/21/2003
Name:       CUTTYHUNK POND ENTRANCE, CUTTYHUNK HARBOR         
            MASSACHUSETTS
NOAA Chart: 13230                                  Latitude:         41° 25.5' N
USGS Quad:  CUTTYHUNK                              Longitude:        70° 55.0' 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.