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

                                                                                
Station ID: 9464961                         PUBLICATION DATE:  03/19/2019
Name:       CAPE CONSTANTINE, NUSHAGAK PENINSULA              
            AK
NOAA Chart:                                 Latitude:   58° 31.3' N (  58.52169)
USGS Quad:                                  Longitude: 159°  9.1' W (-159.15200)





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


                 PRIMARY BENCH MARK STAMPING:  4961 K 1986
                         DESIGNATION:          946 4961 K 1986

MONUMENTATION:           Survey disk                           VM#:        15297
AGENCY:                  National Ocean Service (NOS)          IDB PID:         
SETTING CLASSIFICATION:  Aluminum prefabricated pipe           OPUS PID:        
LATITUDE:   58° 24.0' N (  58.40000)          LONGITUDE: 158° 55.0' W (-158.91700)


The primary bench mark is a disk attached to the top of a 2-inch diameter
aluminum prefabricated 1.22 m (4.0 ft) pipe mark,  182.88 m (600.0 ft) NE (050 
magnetic) from bench mark 4961 L 1986, 62.12 m (203.8 ft) NE (062  magnetic)
from bench mark 4961 G 1986, and 4.57 m (15.0 ft) inshore from the edge of the
bluff which is 3.35 m (11.0 ft) high at this point and runs parallel to the
beach. The bench mark is attached to the top of a 2-inch diameter aluminum
prefabricated 1.22 m (4.0 ft) pipe mark that projects 0.27 m (0.9 ft) above
natural grade, and set in soilcrete.



                         BENCH MARK STAMPING:  4961 B 1985
                         DESIGNATION:          946 4961 B 1985

MONUMENTATION:           Survey disk                           VM#:        15293
AGENCY:                  National Ocean Service (NOS)          IDB PID:         
SETTING CLASSIFICATION:  Unspecified deep rod                  OPUS PID:        
LATITUDE:   58° 24.0' N (  58.40000)          LONGITUDE: 158° 55.0' W (-158.91700)


The bench mark is a disk attached to a 1/2-inch steel rod driven 1.83 m (6.0 ft)
into the ground, 40.0 m (131.2 ft) inland of the bank that runs along the beach,
7.60 m (24.9 ft) west of a peat bog in a peat mound, and about 2.0 m (6.6 ft)
above the approximate high water line.

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

                                                                                
Station ID: 9464961                         PUBLICATION DATE:  03/19/2019
Name:       CAPE CONSTANTINE, NUSHAGAK PENINSULA              
            AK
NOAA Chart:                                 Latitude:   58° 31.3' N (  58.52169)
USGS Quad:                                  Longitude: 159°  9.1' W (-159.15200)


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


                         BENCH MARK STAMPING:  4961 G 1986
                         DESIGNATION:          946 4961 G 1986

MONUMENTATION:           Survey disk                           VM#:        15294
AGENCY:                  National Ocean Service (NOS)          IDB PID:         
SETTING CLASSIFICATION:  Stainless steel rod                   OPUS PID:        
LATITUDE:   58° 24.0' N (  58.40000)          LONGITUDE: 158° 55.0' W (-158.91700)


The bench mark is a disk attached to the top of a stainless steel rod, 62.12 m
(203.8 ft) NE (062  magnetic) from bench mark 4961 K 1986, 84.28 m (276.5 ft) NE
(060  magnetic) from bench mark 4961 H 1986, and 22.86 m (75.0 ft) inshore from
a steep bluff which runs parallel to the beach.  The bench mark is flush with
the natural grade, attached to the top of a stainless steel rod, driven 7.32 m
(24.0 ft) to refusal, and protected by a 4-inch PVC pipe 0.3 m (1 ft) long
projecting 0.06 m (0.2 ft) above natural grade and set in soilcrete.



                         BENCH MARK STAMPING:  4961 H 1986
                         DESIGNATION:          946 4961 H 1986

MONUMENTATION:           Survey disk                           VM#:        15295
AGENCY:                  National Ocean Service (NOS)          IDB PID:         
SETTING CLASSIFICATION:  Stainless steel rod                   OPUS PID:        
LATITUDE:   58° 24.0' N (  58.40000)          LONGITUDE: 158° 55.0' W (-158.91700)


The bench mark is a disk attached to the top of a stainless steel rod, 84.28 m
(276.5 ft) NE (060  magnetic) from bench mark 4961 G 1986, 72.69 m (238.5 ft) NE
(055  magnetic) from bench mark 4961 J 1986, and 45.72 m (150.0 ft) inshore from
a steep bluff which runs parallel to the beach.  The bench mark is flush with
the natural grade, attached to the top of a stainless steel rod, driven 5.49 m
(18.0 ft) to refusal, and protected by a 4-inch PVC pipe 0.3 m (1 ft) long
projecting 0.06 m (0.2 ft) above natural grade and set in soilcrete.

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

                                                                                
Station ID: 9464961                         PUBLICATION DATE:  03/19/2019
Name:       CAPE CONSTANTINE, NUSHAGAK PENINSULA              
            AK
NOAA Chart:                                 Latitude:   58° 31.3' N (  58.52169)
USGS Quad:                                  Longitude: 159°  9.1' W (-159.15200)


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


                         BENCH MARK STAMPING:  4961 J 1986
                         DESIGNATION:          946 4961 J 1986

MONUMENTATION:           Survey disk                           VM#:        15296
AGENCY:                  National Ocean Service (NOS)          IDB PID:         
SETTING CLASSIFICATION:  Stainless steel rod                   OPUS PID:        
LATITUDE:   58° 24.0' N (  58.40000)          LONGITUDE: 158° 55.0' W (-158.91700)


The bench mark is a disk attached to the top of a stainless steel rod, 72.69 m
(238.5 ft) NE (055  magnetic) from bench mark 4961 H 1986, NE (080  magnetic)
from Round Island, and 68.58 m (225.0 ft) inshore from a steep bluff which runs
parallel to the beach.  The bench mark is flush with the natural grade, attached
to the top of a stainless steel rod, driven 2.44 m (8.0 ft) to substantial
resistance, and protected by a 4-inch PVC pipe 0.55 m (1.8 ft) long projecting
0.06 m (0.2 ft) above natural grade and set in soilcrete.

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

                                                                                
Station ID: 9464961                         PUBLICATION DATE:  03/19/2019
Name:       CAPE CONSTANTINE, NUSHAGAK PENINSULA              
            AK
NOAA Chart:                                 Latitude:   58° 31.3' N (  58.52169)
USGS Quad:                                  Longitude: 159°  9.1' W (-159.15200)


                            T I D A L   D A T U M S 


Tidal datums at CAPE CONSTANTINE, NUSHAGAK PENINSULA based on:

     LENGTH OF SERIES:      1 MONTH
     TIME PERIOD:           July 1986 - July 1986
     TIDAL EPOCH:           1983-2001
     CONTROL TIDE STATION:  9463502 PORT MOLLER, BRISTOL BAY


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

     MEAN HIGHER HIGH WATER                     MHHW   =  3.400
     MEAN HIGH WATER                            MHW    =  3.072
     MEAN SEA LEVEL                             MSL    =  1.844
     MEAN TIDE LEVEL                            MTL    =  1.834
     MEAN LOW WATER                             MLW    =  0.596
     MEAN LOWER LOW WATER                       MLLW   =  0.000



Bench Mark Elevation Information                In METERS above:

     Stamping or Designation                    MLLW        MHW

     4961 K 1986                                 9.647    6.575
     4961 B 1985                                 8.719    5.647
     4961 G 1986                                10.148    7.076
     4961 H 1986                                11.437    8.365
     4961 J 1986                                11.691    8.619


Foot Notes:

Data from this station was collected using methodology that does not meet CO-OPS
highest level of accuracy (no more than 10 cm, 95% Confidence Interval (CI)
referenced to a tidal datum). Recognizing that lower quality data can be used
for certain applications CO-OPS is making this data available to its users with
restraint. The average six-minute water level observations derived from this
system have an accuracy ranging from 10.0 - 30.0 cm, 95% CI on datum. Users are
cautioned to consider the accuracy of these data before using them for critical
navigational or coastal engineering purposes.

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

                                                                                
Station ID: 9464961                         PUBLICATION DATE:  03/19/2019
Name:       CAPE CONSTANTINE, NUSHAGAK PENINSULA              
            AK
NOAA Chart:                                 Latitude:   58° 31.3' N (  58.52169)
USGS Quad:                                  Longitude: 159°  9.1' W (-159.15200)


                             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.