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Bench Mark Sheet for 8417948, PRINCE POINT, YARMOUTH ME

Superseded Epoch

Large map location marker Station Location
Small red map location marker Published bench mark
Small blue map location marker Unpublished bench mark

Bench mark positions only appear on the map if their coordinates in the CO-OPS database are at the precision of degrees/minutes/seconds/and tenths of seconds. If the coordinates are less precise, the mark will not appear.

Printable version

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

                                                                                
Station ID: 8417948                         PUBLICATION DATE:  04/29/2004
Name:       PRINCE POINT, YARMOUTH                            
            ME
NOAA Chart: 13290                           Latitude:   43° 45.7' N (  43.76170)
USGS Quad:  YARMOUTH                        Longitude:  70° 10.4' W ( -70.17330)


To reach the tidal bench marks from Portland, Maine, proceed 3.2 km (2 mi) north
on US Route 1 to the intersection of State Road 88, bear right onto State Route
88 and travel 9.7 km (6 mi) to Princess Point road, and turn right (south) and
continue 1.6 km (1 mi) to Prince Point located in the SW section of Casco Bay. 
The bench marks were located in the vicinity of the Princes Point Association
Pier and extend east along the shoreline.  The tide gage and staff were located
on the pier.


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


                 PRIMARY BENCH MARK STAMPING:  841 7948 A 1979
                         DESIGNATION:          841 7948 A TIDAL

MONUMENTATION:           Tidal Station disk                    VM#:         1910
AGENCY:                  National Ocean Survey (NOS)           IDB PID#:        
SETTING CLASSIFICATION:  Concrete support piling               OPUS PID:        
LATITUDE:   43° 45.7' N (  43.76170)          LONGITUDE:  70° 10.4' W ( -70.17330)


The primary bench mark is a disk set flush in a concrete support piling for the
Princes Point Association Pier, 1.6 m (5.2 ft) above beach level, bearing NW
from the large stack at the power plant on Cousins Island and NNE from a small
island known as Nubbin which is just off the coast from the pier.

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

                                                                                
Station ID: 8417948                         PUBLICATION DATE:  04/29/2004
Name:       PRINCE POINT, YARMOUTH                            
            ME
NOAA Chart: 13290                           Latitude:   43° 45.7' N (  43.76170)
USGS Quad:  YARMOUTH                        Longitude:  70° 10.4' W ( -70.17330)


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


                         BENCH MARK STAMPING:  841 7948 B 1979
                         DESIGNATION:          841 7948 B TIDAL

MONUMENTATION:           Tidal Station disk                    VM#:         1911
AGENCY:                  National Ocean Survey (NOS)           IDB PID#:        
SETTING CLASSIFICATION:  Rock ledge                            OPUS PID:        
LATITUDE:   43° 45.7' N (  43.76170)          LONGITUDE:  70° 10.4' W ( -70.17330)


The bench mark is a disk set flush on a rock ledge east of the Princes Point
Association Pier, 2.2 m (7.3 ft) NW of the shoreline, 1.7 m (5.7 ft) SE of the
seawall, bearing NE from bench mark 841 7948 A 1979, and NW of the large stack
at the power plant on Cousins Island.



                         BENCH MARK STAMPING:  841 7948 C 1979
                         DESIGNATION:          841 7948 C TIDAL

MONUMENTATION:           Tidal Station disk                    VM#:         1912
AGENCY:                  National Ocean Survey (NOS)           IDB PID#:        
SETTING CLASSIFICATION:  Rock ledge                            OPUS PID:        
LATITUDE:   43° 45.7' N (  43.76170)          LONGITUDE:  70° 10.4' W ( -70.17330)


The bench mark is a disk set flush on a rock ledge east of the Princes Point
Association Pier, 17.5 m (57.3 ft) NE of bench mark 841 7948 B 1979, bearing NW
from the large stack at the power plant on Cousins Islands, NNE from a small
island knows as Nubbins off the coast from the pier, and NNE from the NE corner
of the seawall that is located along the rock ledge.

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

                                                                                
Station ID: 8417948                         PUBLICATION DATE:  04/29/2004
Name:       PRINCE POINT, YARMOUTH                            
            ME
NOAA Chart: 13290                           Latitude:   43° 45.7' N (  43.76170)
USGS Quad:  YARMOUTH                        Longitude:  70° 10.4' W ( -70.17330)


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


                         BENCH MARK STAMPING:  841 7948 D 1979
                         DESIGNATION:          841 7948 D TIDAL

MONUMENTATION:           Tidal Station disk                    VM#:         1913
AGENCY:                  National Ocean Survey (NOS)           IDB PID#:        
SETTING CLASSIFICATION:  Rock ledge                            OPUS PID#: BBBG16
LATITUDE:   43° 45.7' N (  43.76170)          LONGITUDE:  70° 10.4' W ( -70.17330)


The bench mark is a disk set flush on a rock ledge east of the Princes Point
Association Pier, 32.3 m (106 ft) NE of bench mark 841 7948 C 1979, 7.0 m (23.0
ft) west of the shoreline, 1.2 m (4.0 ft)  from the edge of a small cliff,
bearing NW of the large stack at the power plant on Cousins Island and NE from a
small island known as Nubbin off the coast from the pier.



                         BENCH MARK STAMPING:  841 7948 E 1979
                         DESIGNATION:          841 7948 E TIDAL

MONUMENTATION:           Tidal Station disk                    VM#:         1914
AGENCY:                  National Ocean Survey (NOS)           IDB PID#:        
SETTING CLASSIFICATION:  Rock ledge                            OPUS PID:        
LATITUDE:   43° 45.7' N (  43.76170)          LONGITUDE:  70° 10.4' W ( -70.17330)


The bench mark is a disk set flush on a rock ledge east of the Princes Point
Association Pier, 14.8 m (48.5 ft)  NE of bench mark 841 7948 D 1979, and bears
north NW from the large stack at the power plant on Cousins Island.

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

                                                                                
Station ID: 8417948                         PUBLICATION DATE:  04/29/2004
Name:       PRINCE POINT, YARMOUTH                            
            ME
NOAA Chart: 13290                           Latitude:   43° 45.7' N (  43.76170)
USGS Quad:  YARMOUTH                        Longitude:  70° 10.4' W ( -70.17330)


                            T I D A L   D A T U M S 


Tidal datums at PRINCE POINT, YARMOUTH based on:

     LENGTH OF SERIES:      1 MONTH
     TIME PERIOD:           October 1979 - October 1979
     TIDAL EPOCH:           1983-2001
     CONTROL TIDE STATION:  8418150 PORTLAND, CASCO BAY


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

     MEAN HIGHER HIGH WATER                     MHHW   =  3.031
     MEAN HIGH WATER                            MHW    =  2.894
     MEAN SEA LEVEL                             MSL    =  1.507
     MEAN TIDE LEVEL                            MTL    =  1.494
     MEAN LOW WATER                             MLW    =  0.095
     MEAN LOWER LOW WATER                       MLLW   =  0.000

North American Vertical Datum (NAVD88)

Bench Mark Elevation Information                In METERS above:

     Stamping or Designation                    MLLW        MHW

     841 7948 A 1979                             4.438    1.544
     841 7948 B 1979                             3.892    0.998
     841 7948 C 1979                             3.441    0.547
     841 7948 D 1979                             3.571    0.677
     841 7948 E 1979                             4.115    1.221


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

                                                                                
Station ID: 8417948                         PUBLICATION DATE:  04/29/2004
Name:       PRINCE POINT, YARMOUTH                            
            ME
NOAA Chart: 13290                           Latitude:   43° 45.7' N (  43.76170)
USGS Quad:  YARMOUTH                        Longitude:  70° 10.4' W ( -70.17330)


                             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.

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Products available at 8417948 PRINCE POINT, YARMOUTH, ME

Revised: 08/08/2018
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