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

                                                                                
Station ID: 9466328                         PUBLICATION DATE:  03/09/2011
Name:       LOMAVIK, AK                                       
            AK
NOAA Chart: 16304                           Latitude:   60° 33.3' N (  60.55428)
USGS Quad:  BAIRD INLET (A-2)               Longitude: 162° 17.8' W (-162.29714)


To reach the tidal bench marks from the Bethel, proceed by charter float plane
39 km (24 mi) SW to a small slough on the west bank of the Kuskokwim River, taxi
0.3 km (0.2 mi) south along the bank of the Kuskokwim River. The bench marks are
located between 20 m and 150 m from the river bank. The tide gauges were located
approximate 50 m (164 ft) offshore.


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


                 PRIMARY BENCH MARK STAMPING:  6328 A 2010
                         DESIGNATION:          946 6328 A

MONUMENTATION:           Metal Rod                             VM#:        19673
AGENCY:                  National Ocean Service (NOS)          IDB PID#:        
SETTING CLASSIFICATION:  Stainless steel rod                   OPUS PID:        
LATITUDE:   60° 33.3' N (  60.55444)          LONGITUDE: 162° 17.8' W (-162.29625)


The primary bench mark is set on the west bank of the Kuskokwim River, 66.43 m
(217.8 ft) north of bench mark 946 6328 C, 32.50 m (106.6 ft) WNW of the bank of
the Kuskokwim River, and 12.65 m (41.5 ft) south of a small drainage creek that
trickles into the Kuskokwim River.  The datum point is set 0.09 m (0.3 ft) below
grade, being the top of a rounded off stainless steel rod with a punch mark
driven 6.1 m (20 ft) to refusal and encased in a NGS Geodetic Control Mark Logo
cover.

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

                                                                                
Station ID: 9466328                         PUBLICATION DATE:  03/09/2011
Name:       LOMAVIK, AK                                       
            AK
NOAA Chart: 16304                           Latitude:   60° 33.3' N (  60.55428)
USGS Quad:  BAIRD INLET (A-2)               Longitude: 162° 17.8' W (-162.29714)


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


                         BENCH MARK STAMPING:  6328 B 2010
                         DESIGNATION:          946 6328 B

MONUMENTATION:           Metal Rod                             VM#:        19674
AGENCY:                  National Ocean Service (NOS)          IDB PID#:        
SETTING CLASSIFICATION:  Stainless steel rod                   OPUS PID#: BBBZ38
LATITUDE:   60° 33.3' N (  60.55419)          LONGITUDE: 162° 17.8' W (-162.29736)


The bench mark is set on the west bank of the Kuskokwim River, 71.47 m (234.5
ft) WSW of bench mark 946 6328 A, 60.06 m (198.8 ft) WNW of bench mark 946 6328
C, and 16.83 m (55.2 ft) north of a line an alders that run east/west.  The
datum point is set 0.09 m (0.3 ft) below grade, being the top of a rounded off
stainless steel rod with a punch mark driven 10.9 m (36 ft) to refusal and
encased in a NGS Geodetic Mark Logo Cover.



                         BENCH MARK STAMPING:  6328 C 2010
                         DESIGNATION:          946 6328 C

MONUMENTATION:           Metal Rod                             VM#:        19675
AGENCY:                  National Ocean Service (NOS)          IDB PID#:        
SETTING CLASSIFICATION:  Stainless steel rod                   OPUS PID:        
LATITUDE:   60° 33.2' N (  60.55386)          LONGITUDE: 162° 17.8' W (-162.29636)


The bench mark is set on the west bank of the Kuskokwim River, 61.00 m (200.1
ft) NE of bench mark 946 6328 D, 60.06 m (198.8 ft) ESE  of bench mark 946 6328
B, 28.79 m (94.5 ft) east of the edge of alders running east/west along another
slightly larger drainage creek that runs between benchmarks 946 6328 C and 946
6328 D and flows into the Kuskokwim River, and 23.50 m (77.1 ft) north of the
outlet of the same slightly larger drainage creek.  The datum point is set 0.10
m (0.3 ft) below grade, being the top of a rounded off stainless steel rod with
a punch mark driven 15.8 m (52 ft) to refusal and encased in a NGS Geodetic
Control Mark Logo cover.

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

                                                                                
Station ID: 9466328                         PUBLICATION DATE:  03/09/2011
Name:       LOMAVIK, AK                                       
            AK
NOAA Chart: 16304                           Latitude:   60° 33.3' N (  60.55428)
USGS Quad:  BAIRD INLET (A-2)               Longitude: 162° 17.8' W (-162.29714)


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


                         BENCH MARK STAMPING:  6328 D 2010
                         DESIGNATION:          946 6328 D

MONUMENTATION:           Metal Rod                             VM#:        19676
AGENCY:                  National Ocean Service (NOS)          IDB PID#:        
SETTING CLASSIFICATION:  Stainless steel rod                   OPUS PID:        
LATITUDE:   60° 33.2' N (  60.55353)          LONGITUDE: 162° 17.8' W (-162.29736)


The bench mark is set on the west bank of the Kuskowkim River, 61.00 m (200.1
ft) SW of bench mark 946 6328 C, 55.02 m (180.5 ft) east of bench mark 946 6328
E, 52.40 m (171.9 ft) west of the bank of the Kuskokwim River, and 33.70 m
(110.6 ft) south of a driftwood debris pile near a line of alders running
east/west.  The datum point is set 0.07 m (0.2 ft) below grade, being the top of
a rounded off stainless steel rod with a punch mark driven 12.2 m (39.9 ft) to
refusal and encased in a NGS Geodetic Control Mark Logo cover.



                         BENCH MARK STAMPING:  6328 E 2010
                         DESIGNATION:          946 6328 E

MONUMENTATION:           Metal Rod                             VM#:        19677
AGENCY:                  National Ocean Service (NOS)          IDB PID#:        
SETTING CLASSIFICATION:  Stainless steel rod                   OPUS PID:        
LATITUDE:   60° 33.2' N (  60.55356)          LONGITUDE: 162° 17.9' W (-162.29828)


The bench mark is set on the west bank of the Kuskokwim River, 55.70 m (182.7
ft) NW of the grass edge of small bay south of the slightly larger drainage
creek, 55.02 m (180.5 ft) west of bench mark 946 6328 D, and 46.90 m (153.9 ft)
SE of SW point of large driftwood pile congrated near a line of alders.  The
datum point is set 0.07 m (0.2 ft) below grade, being the top of a rounded off
stainless steel rod with a punch mark driven 12.2 m (40.0 ft) to refusal and
encased in a NGS Geodetic Control Mark Logo. cover.

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

                                                                                
Station ID: 9466328                         PUBLICATION DATE:  03/09/2011
Name:       LOMAVIK, AK                                       
            AK
NOAA Chart: 16304                           Latitude:   60° 33.3' N (  60.55428)
USGS Quad:  BAIRD INLET (A-2)               Longitude: 162° 17.8' W (-162.29714)


                            T I D A L   D A T U M S 


Tidal datums at LOMAVIK, AK based on:

     LENGTH OF SERIES:      2 MONTHS
     TIME PERIOD:           July 2010 - August 2010
     TIDAL EPOCH:           1983-2001
     CONTROL TIDE STATION:   


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

     MEAN HIGHER HIGH WATER                     MHHW   =  2.415
     MEAN HIGH WATER                            MHW    =  1.933
     MEAN SEA LEVEL                             MSL    =  1.183
     MEAN TIDE LEVEL                            MTL    =  1.073
     MEAN LOW WATER                             MLW    =  0.213
     MEAN LOWER LOW WATER                       MLLW   =  0.000

North American Vertical Datum (NAVD88)

Bench Mark Elevation Information                In METERS above:

     Stamping or Designation                    MLLW        MHW

     6328 A 2010                                 2.453    0.520
     6328 B 2010                                 2.492    0.559
     6328 C 2010                                 2.523    0.590
     6328 D 2010                                 2.520    0.587
     6328 E 2010                                 2.475    0.542


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

                                                                                
Station ID: 9466328                         PUBLICATION DATE:  03/09/2011
Name:       LOMAVIK, AK                                       
            AK
NOAA Chart: 16304                           Latitude:   60° 33.3' N (  60.55428)
USGS Quad:  BAIRD INLET (A-2)               Longitude: 162° 17.8' W (-162.29714)


                             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.