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

                                                                                
Station ID: 8447173                         PUBLICATION DATE:  04/21/2003
Name:       STATION 115, CAPE COD CANAL                       
            MA
NOAA Chart: 13236                           Latitude:   41° 46.4' N (  41.77330)
USGS Quad:  SAGAMORE                        Longitude:  70° 32.1' W ( -70.53500)


To reach the tidal bench marks from the traffic circle on U.S. Highway 6 in
Sagamore, at the south end of the highway bridge over the Cape Cod Canal,
proceed east on U.S. Highway 6 for 0.8 km (0.5 mi), then turn left on Pleasant
Street and continue north to the Development Sciences, Inc. office building. 
The bench marks are located between the Bay Colony Railway tracks and the canal
service road.  The tide gage was located on a 2-pile structure just offshore of
Corps of Engineers station 115+00.


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


                 PRIMARY BENCH MARK STAMPING:  7173 D 1982
                         DESIGNATION:          844 7173 D

MONUMENTATION:           Tidal Station disk                    VM#:         1514
AGENCY:                  National Ocean Survey (NOS)           IDB PID#:        
SETTING CLASSIFICATION:  Stainless steel rod                   OPUS PID:        
LATITUDE:   41° 46.4' N (  41.77330)          LONGITUDE:  70° 32.1' W ( -70.53500)


The primary bench mark is a disk located NW of the Development Sciences, Inc.
building at 39 Pleasant Street, 5.64 m (18.5 ft) north of the northernmost rail
on the southernmost of two railroad tracks, 3.14 m (10.3 ft) south of the Cape
Cod Canal service road, and 0.64 m (2.1 ft) SW of a power pole with a white
cross painted on it.  The bench mark is 6 cm (0.2 ft) below ground, crimped to a
stainless steel rod driven 7.3 m (24 ft) and encased in a PVC pipe with concrete
kickblock.

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

                                                                                
Station ID: 8447173                         PUBLICATION DATE:  04/21/2003
Name:       STATION 115, CAPE COD CANAL                       
            MA
NOAA Chart: 13236                           Latitude:   41° 46.4' N (  41.77330)
USGS Quad:  SAGAMORE                        Longitude:  70° 32.1' W ( -70.53500)


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


                         BENCH MARK STAMPING:  7173 E 1982
                         DESIGNATION:          844 7173 E

MONUMENTATION:           Tidal Station disk                    VM#:         1515
AGENCY:                  National Ocean Survey (NOS)           IDB PID#:        
SETTING CLASSIFICATION:  Stainless steel rod                   OPUS PID:        
LATITUDE:   41° 46.4' N (  41.77330)          LONGITUDE:  70° 32.1' W ( -70.53500)


The bench mark is a disk located SE of Bench Mark 7173 D 1982, 7.32 m (24.0 ft)
north of the northernmost rail of the southernmost of two railroad tracks, 5.55
m (18.2 ft) south of the Cape Cod Canal service road, and 3.90 m (12.8 ft) SW of
a power pole with a white cross painted on it. The bench mark is crimped to a
stainless steel rod driven 4.9 m (16 ft), and encased in a PVC pipe with
concrete kickblock. NOTE: The PVC pipe has been damaged.



                         BENCH MARK STAMPING:  CC 483 1974
                         DESIGNATION:          844 7173 CC 483

MONUMENTATION:           Survey disk                           VM#:         1517
AGENCY:                  US Army Corps of Engineers (USE)      IDB PID#:        
SETTING CLASSIFICATION:  Concrete monument                     OPUS PID:        
LATITUDE:   41° 46.4' N (  41.77330)          LONGITUDE:  70° 32.1' W ( -70.53500)


The bench mark is a disk set in a concrete monument at the west end of a granite
headwall, 78.3 m (257 ft) west of station 115+00, 3.23 m (10.6 ft) south of the
centerline of the service road, and 2.13 m (7.0 ft) north of the northernmost
rail of two railroad tracks, and 0.15 m (0.5 ft) above ground.

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

                                                                                
Station ID: 8447173                         PUBLICATION DATE:  04/21/2003
Name:       STATION 115, CAPE COD CANAL                       
            MA
NOAA Chart: 13236                           Latitude:   41° 46.4' N (  41.77330)
USGS Quad:  SAGAMORE                        Longitude:  70° 32.1' W ( -70.53500)


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


                         BENCH MARK STAMPING:   
                         DESIGNATION:          844 7173 BOLT

MONUMENTATION:           Bolt                                  VM#:        16510
AGENCY:                  Unknown                               IDB PID#:        
SETTING CLASSIFICATION:  Retaining wall                        OPUS PID:        
LATITUDE:   41° 46.4' N (  41.77330)          LONGITUDE:  70° 32.1' W ( -70.53500)


The bench mark is a bolt set in a concrete retaining wall at the west side of
the entrance to the parking lot for Development Sciences, Inc. at 39 Pleasant
Street, 7.0 m (23 ft) north of the centerline of Pleasant Street, 1.02 m (3.3
ft) NE of power pole No. 265/1, 0.26 m (0.9 ft) west of the east end of the
wall, and at ground level on the south side of the wall.



                         BENCH MARK STAMPING:  7173 F 2001
                         DESIGNATION:          844 7173 F

MONUMENTATION:           Tidal Station disk                    VM#:        16511
AGENCY:                  National Ocean Service (NOS)          IDB PID#:        
SETTING CLASSIFICATION:  Concrete pole base                    OPUS PID:        
LATITUDE:   41° 46.4' N (  41.77330)          LONGITUDE:  70° 32.1' W ( -70.53500)


The bench mark is a disk set in the SE corner of the concrete light pole base at
Station 115, 39.22 m (128.7 ft) SE of the first power pole east of Station 115,
5.70 m (18.7 ft) NNE of the Station 115 pole, 0.15 m (0.5 ft) NE of the SE
corner of the base, and 0.10 m (0.3 ft) below the service road.

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

                                                                                
Station ID: 8447173                         PUBLICATION DATE:  04/21/2003
Name:       STATION 115, CAPE COD CANAL                       
            MA
NOAA Chart: 13236                           Latitude:   41° 46.4' N (  41.77330)
USGS Quad:  SAGAMORE                        Longitude:  70° 32.1' W ( -70.53500)


                            T I D A L   D A T U M S 


Tidal datums at STATION 115, CAPE COD CANAL based on:

     LENGTH OF SERIES:      3 Months
     TIME PERIOD:           July 2001 - September 2001
     TIDAL EPOCH:           1983-2001
     CONTROL TIDE STATION:  8443970 BOSTON, BOSTON HARBOR


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

     MEAN HIGHER HIGH WATER                     MHHW   =  2.618
     MEAN HIGH WATER                            MHW    =  2.499
     MEAN SEA LEVEL                             MSL    =  1.345
     MEAN TIDE LEVEL                            MTL    =  1.295
     MEAN LOW WATER                             MLW    =  0.092
     MEAN LOWER LOW WATER                       MLLW   =  0.000

North American Vertical Datum (NAVD88)

Bench Mark Elevation Information                In METERS above:

     Stamping or Designation                    MLLW        MHW

     7173 D 1982                                 6.277    3.778
     7173 E 1982                                 5.924    3.425
     CC 483 1974                                 6.938    4.439
     844 7173 BOLT                               7.412    4.913
     7173 F 2001                                 6.280    3.781


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

                                                                                
Station ID: 8447173                         PUBLICATION DATE:  04/21/2003
Name:       STATION 115, CAPE COD CANAL                       
            MA
NOAA Chart: 13236                           Latitude:   41° 46.4' N (  41.77330)
USGS Quad:  SAGAMORE                        Longitude:  70° 32.1' W ( -70.53500)


                             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.