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

                                                                                
Station ID: 9451247                         PUBLICATION DATE:  09/11/2008
Name:       MONTE CARLO ISLAND                                
            AK
NOAA Chart: 17372                           Latitude:   55° 32.1' N (  55.53500)
USGS Quad:  PETERSBURG (C-6)                Longitude: 133° 46.0' W (-133.76700)


To reach the bench marks from Point Baker on the north tip of Prince of Wales
Island via boat, go approximately 20.8 km (11.2 nm) NNW crossing Sumner Strait
to Monte Carlo Island at the southern part of the entrance to Keku Straits.  The
tide gauge location is on the north corner of the western shore of the large
bight on the north side of the island. The tidal bench marks are located on the
beach.


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


                 PRIMARY BENCH MARK STAMPING:  4 1937
                         DESIGNATION:          945 1247 TIDAL 4

MONUMENTATION:           Tidal Station disk                    VM#:        18607
AGENCY:                  US Coast and Geodetic Survey
                         (USC&GS)                              IDB PID#:        
SETTING CLASSIFICATION:  Rock outcrop                          OPUS PID:        
LATITUDE:   56° 32.1' N (  56.53500)          LONGITUDE: 133° 46.1' W (-133.76800)


The primary bench mark is a disk set on the top of a NNE/SSW oriented rock
outcrop at a 90 degree bend in the rock beach, approximately 91 m (300 ft) SSW
of bench mark 945 1247 TIDAL 5, 7.71 m (25.3 ft) west of the approximate MHW
line, 6.19 m (20.3 ft) east of the brush and tree line, 2.38 m (7.8 ft) NNE of
the SSW end of the rock outcrop and approximately 2 m (5 ft) higher than the
adjacent rock immediately to the west.

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

                                                                                
Station ID: 9451247                         PUBLICATION DATE:  09/11/2008
Name:       MONTE CARLO ISLAND                                
            AK
NOAA Chart: 17372                           Latitude:   55° 32.1' N (  55.53500)
USGS Quad:  PETERSBURG (C-6)                Longitude: 133° 46.0' W (-133.76700)


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


                         BENCH MARK STAMPING:  5 1937
                         DESIGNATION:          945 1247 TIDAL 5

MONUMENTATION:           Tidal Station disk                    VM#:        18608
AGENCY:                  US Coast and Geodetic Survey
                         (USC&GS)                              IDB PID#:        
SETTING CLASSIFICATION:  Rock outcrop                          OPUS PID#: BBBG77
LATITUDE:   56° 32.1' N (  56.53500)          LONGITUDE: 133° 46.0' W (-133.76700)


The bench mark is a disk set on the top of a NNE/SSW oriented rock islet which
drops off rapidly to the east, approximately 91 m (300 ft) NNE of bench mark 945
1247 Tidal 4, approximately 60 m (197 ft) south of bench mark 945 1247 TIDAL 6,
21.21 m (69.6 ft) SSW of the MHW line at the NNE end of the islet, 16.09 m (52.8
ft) NNE of the SSW end of the islet, and 2.0 m (6.6 ft) WNW of the MHW line.



                         BENCH MARK STAMPING:  6 1937
                         DESIGNATION:          945 1247 TIDAL 6

MONUMENTATION:           Tidal Station disk                    VM#:        18609
AGENCY:                  US Coast and Geodetic Survey
                         (USC&GS)                              IDB PID#:        
SETTING CLASSIFICATION:  Rock outcrop                          OPUS PID:        
LATITUDE:   56° 32.1' N (  56.53500)          LONGITUDE: 133° 46.0' W (-133.76700)


The bench mark is a disk set in the highest point of a solid rock outcrop which
becomes an island at high tide, approximately 60 m (197 ft) north of bench mark
945 1247 TIDAL 5, 4.39 m (14.4 ft) SSW of the approximate MHW line, and 2.3 m
(7.5 ft) NNE of the approximate MHW line.

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

                                                                                
Station ID: 9451247                         PUBLICATION DATE:  09/11/2008
Name:       MONTE CARLO ISLAND                                
            AK
NOAA Chart: 17372                           Latitude:   55° 32.1' N (  55.53500)
USGS Quad:  PETERSBURG (C-6)                Longitude: 133° 46.0' W (-133.76700)


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


                         BENCH MARK STAMPING:  7 1938
                         DESIGNATION:          945 1247 TIDAL 7

MONUMENTATION:           Tidal Station disk                    VM#:        18610
AGENCY:                  US Coast and Geodetic Survey
                         (USC&GS)                              IDB PID#:        
SETTING CLASSIFICATION:  Rock outcrop                          OPUS PID:        
LATITUDE:   56° 32.0' N (  56.53330)          LONGITUDE: 133° 46.1' W (-133.76800)


The bench mark is a disk set on the top of a NNE / SSW oriented rock outcrop,
47.49 m (155.8 ft) SSE of bench mark 945 1247 A, 16.9 m (55.4 ft) SE of the
south end of a 20 m (66 ft) long gravel beach, and 3.41 m (11.2 ft) west of the
approximate MHW line.



                         BENCH MARK STAMPING:  1247 A 2007
                         DESIGNATION:          945 1247 A

MONUMENTATION:           Tidal Station disk                    VM#:        18611
AGENCY:                  National Ocean Service (NOS)          IDB PID#:        
SETTING CLASSIFICATION:  Rock outcrop                          OPUS PID:        
LATITUDE:   56° 32.0' N (  56.53330)          LONGITUDE: 133° 46.1' W (-133.76800)


The bench mark is a disk set on the top of a black colored NNE/SSW oriented rock
outcrop at the north end of a 20 m (66 ft) long gravel beach and the south end
of a 15 m (49 ft) rocky beach, 47.48 m (155.8 ft) NNW of bench mark 945 1247
TIDAL 7, 16.70 m (54.8 ft) west of the tree line, 11.31 m (37.1 ft) NNE of the
north end of the gravel beach, and 2 m (6 ft) west of the approximate MHW line.

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

                                                                                
Station ID: 9451247                         PUBLICATION DATE:  09/11/2008
Name:       MONTE CARLO ISLAND                                
            AK
NOAA Chart: 17372                           Latitude:   55° 32.1' N (  55.53500)
USGS Quad:  PETERSBURG (C-6)                Longitude: 133° 46.0' W (-133.76700)


                            T I D A L   D A T U M S 


Tidal datums at MONTE CARLO ISLAND based on:

     LENGTH OF SERIES:      1 MONTH
     TIME PERIOD:           August 2007 - August 2007
     TIDAL EPOCH:           1983-2001
     CONTROL TIDE STATION:  9450460 KETCHIKAN, TONGASS NARROWS


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

     MEAN HIGHER HIGH WATER                     MHHW   =  3.861
     MEAN HIGH WATER                            MHW    =  3.606
     MEAN TIDE LEVEL                            MTL    =  2.028
     MEAN SEA LEVEL                             MSL    =  2.013
     MEAN LOW WATER                             MLW    =  0.450
     MEAN LOWER LOW WATER                       MLLW   =  0.000

North American Vertical Datum (NAVD88)

Bench Mark Elevation Information                In METERS above:

     Stamping or Designation                    MLLW        MHW

     4 1937                                      5.709    2.103
     5 1937                                      4.880    1.274
     6 1937                                      5.023    1.417
     7 1938                                      4.189    0.583
     1247 A 2007                                 4.327    0.721


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

                                                                                
Station ID: 9451247                         PUBLICATION DATE:  09/11/2008
Name:       MONTE CARLO ISLAND                                
            AK
NOAA Chart: 17372                           Latitude:   55° 32.1' N (  55.53500)
USGS Quad:  PETERSBURG (C-6)                Longitude: 133° 46.0' W (-133.76700)


                             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.