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

                                                                                
Station ID: 8415709                         PUBLICATION DATE:  04/01/2004
Name:       THOMASTON, ST GEORGE RIVER                        
            ME
NOAA Chart: 13301                           Latitude:   44°  4.3' N (  44.07170)
USGS Quad:  THOMASTON                       Longitude:  69° 10.9' W ( -69.18170)


To reach the tidal bench marks from the intersection of US Highway 1 and Knox
Street in Thomaston, proceed 0.8 km (0.5 mi) south on Knox Street to the foot of
the street at the waterfront, and the property of the Lyman and Morse
Boatbuilding Company.  The bench marks are located on the property and along the
Maine Central Railroad.  The tide gauge was located on the SW corner of the
wooden bulkhead on the south side of Building 7 at the boat yard.


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


                 PRIMARY BENCH MARK STAMPING:  5709 B 2003
                         DESIGNATION:          841 5709 B

MONUMENTATION:           Tidal Station disk                    VM#:        17280
AGENCY:                  National Ocean Service (NOS)          IDB PID#:        
SETTING CLASSIFICATION:  Loading bay door sill                 OPUS PID:        
LATITUDE:   44°  4.4' N (  44.07330)          LONGITUDE:  69° 10.8' W ( -69.18000)


The primary bench mark is a disk set in the concrete sill for a large overhead
door (easternmost of three doors) on the north side of Building 3 (red aluminum
siding) at the Lyman and Morse Boatbuilding Company, east of the railroad
crossing of Knox street, 23.43 m (76.9 ft) ESE of the NW corner of Building 3,
5.50 m (18.0 ft) SW of the SW corner of the main office (Building 2), and 0.23 m
(0.8 ft) WNW of the east edge of the overhead door.    Handheld GPS: N 44d 04m
23.2s, W 069d 10m 47.2s

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

                                                                                
Station ID: 8415709                         PUBLICATION DATE:  04/01/2004
Name:       THOMASTON, ST GEORGE RIVER                        
            ME
NOAA Chart: 13301                           Latitude:   44°  4.3' N (  44.07170)
USGS Quad:  THOMASTON                       Longitude:  69° 10.9' W ( -69.18170)


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


                         BENCH MARK STAMPING:  5709 A 2003
                         DESIGNATION:          844 5709 A

MONUMENTATION:           Tidal Station disk                    VM#:        17122
AGENCY:                  National Ocean Service (NOS)          IDB PID#:        
SETTING CLASSIFICATION:  Loading bay door sill                 OPUS PID:        
LATITUDE:   44°  4.3' N (  44.07170)          LONGITUDE:  69° 10.8' W ( -69.18000)


The bench mark is a disk set in the concrete sill for a large overhead door
(middle and largest of three doors) on the north side of building 7 (gray shake
siding) at the Lyman and Morse Boatbuilding Company, 33.00 m (108.3 ft) SE of
the north end of the wooden retaining wall at the boat launch ramp, 32.22 m
(105.7 ft) WSW of the southernmost utility pole at the boatyard, and 2.08 m (6.8
ft) ESE of the NW corner of the front middle section of the building.   
Handheld GPS: N 44d 04m 18.0s, W 069d 10m 50.6s

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

                                                                                
Station ID: 8415709                         PUBLICATION DATE:  04/01/2004
Name:       THOMASTON, ST GEORGE RIVER                        
            ME
NOAA Chart: 13301                           Latitude:   44°  4.3' N (  44.07170)
USGS Quad:  THOMASTON                       Longitude:  69° 10.9' W ( -69.18170)


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


                         BENCH MARK STAMPING:  A 18 1933 56.119
                         DESIGNATION:          A 18=TIDAL MARK

MONUMENTATION:           Tidal Station disk                    VM#:        17281
AGENCY:                  US Coast & Geodetic Survey
                         (USC&GS)                                 IDB PID#:  PE0883
SETTING CLASSIFICATION:  Building                              OPUS PID:        
LATITUDE:   44°  4.4' N (  44.07330)          LONGITUDE:  69° 10.8' W ( -69.18000)


The bench mark is a disk set vertically near the SE corner of a brick building
housing the Thomaston Historical Society, 88 m (289 ft) east of Knox street,
3.37 m (11.1 ft) north of the north rail of the tracks,  0.32 m (1.0 ft) north
of the SE corner of the building, and 0.44 m (1.4 ft) above the concrete
foundation apron.    Handheld GPS: N 44d 04m 24.3s, W 069d 10m 47.1s

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

                                                                                
Station ID: 8415709                         PUBLICATION DATE:  04/01/2004
Name:       THOMASTON, ST GEORGE RIVER                        
            ME
NOAA Chart: 13301                           Latitude:   44°  4.3' N (  44.07170)
USGS Quad:  THOMASTON                       Longitude:  69° 10.9' W ( -69.18170)


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


                         BENCH MARK STAMPING:  NO. 4 1948
                         DESIGNATION:          TIDAL 4 STA 40

MONUMENTATION:           Tidal Station disk                    VM#:        17282
AGENCY:                  US Coast & Geodetic Survey
                         (USC&GS)                                 IDB PID#:  PE1066
SETTING CLASSIFICATION:  Building foundation                   OPUS PID:        
LATITUDE:   44°  4.3' N (  44.07170)          LONGITUDE:  69° 10.8' W ( -69.18000)


The bench mark is a disk set vertically in the west wall at the SW corner of the
foundation for a blue-gray boat shed located east of Building 7 at the Lyman and
Morse Boatbuilding Company, 43.10 m (141.4 ft) east of the east wall of Building
7, 0.14 m (0.5 ft) north of the SW corner, 1 m (3 ft) above the granite rip-rap,
and 0.8 m (2.6 ft) below the clapboard siding of the building.    Handheld GPS:
N 44d 04m 17.1s, W 069d 10m 48.0s

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

                                                                                
Station ID: 8415709                         PUBLICATION DATE:  04/01/2004
Name:       THOMASTON, ST GEORGE RIVER                        
            ME
NOAA Chart: 13301                           Latitude:   44°  4.3' N (  44.07170)
USGS Quad:  THOMASTON                       Longitude:  69° 10.9' W ( -69.18170)


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


                         BENCH MARK STAMPING:  NO 5 1954
                         DESIGNATION:          TIDAL 5 STA 40

MONUMENTATION:           Tidal Station disk                    VM#:        17283
AGENCY:                  US Coast & Geodetic Survey
                         (USC&GS)                                 IDB PID#:  PE1064
SETTING CLASSIFICATION:  Signal light base                     OPUS PID:        
LATITUDE:   44°  4.4' N (  44.07330)          LONGITUDE:  69° 10.8' W ( -69.18000)


The bench mark is a disk set in the NE corner of an abandoned railroad sign
base, near the entrance to the Lyman and Morse Boatbuilding Company property,
4.94 m (16.2 ft) west of the centerline of Knox Street, 2.78 m (9.1 ft) NNE of
the north rail of the tracks, and 1.10 m (3.6 ft) south of railroad signal pole
No. 365 820V.    Handheld GPS: N 44d 04m 24.2s, W 069d 10m 51.1s

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

                                                                                
Station ID: 8415709                         PUBLICATION DATE:  04/01/2004
Name:       THOMASTON, ST GEORGE RIVER                        
            ME
NOAA Chart: 13301                           Latitude:   44°  4.3' N (  44.07170)
USGS Quad:  THOMASTON                       Longitude:  69° 10.9' W ( -69.18170)


                            T I D A L   D A T U M S 


Tidal datums at THOMASTON, ST GEORGE RIVER based on:

     LENGTH OF SERIES:      3 MONTHS
     TIME PERIOD:           July 2003 - September 2003
     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   =  3.000
     MEAN HIGH WATER                            MHW    =  2.875
     MEAN SEA LEVEL                             MSL    =  1.508
     MEAN TIDE LEVEL                            MTL    =  1.498
     North American Vertical Datum              NAVD88 =  1.358
     MEAN LOW WATER                             MLW    =  0.120
     MEAN LOWER LOW WATER                       MLLW   =  0.000

North American Vertical Datum (NAVD88)

Bench Mark Elevation Information                In METERS above:

     Stamping or Designation                    MLLW        MHW

     5709 B 2003                                16.927   14.052
     5709 A 2003                                 4.169    1.294
     A 18 1933 56.119                           18.252   15.377
     NO. 4 1948                                  4.496    1.621
     NO 5 1954                                  18.119   15.244


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

                                                                                
Station ID: 8415709                         PUBLICATION DATE:  04/01/2004
Name:       THOMASTON, ST GEORGE RIVER                        
            ME
NOAA Chart: 13301                           Latitude:   44°  4.3' N (  44.07170)
USGS Quad:  THOMASTON                       Longitude:  69° 10.9' W ( -69.18170)


                             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.