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

                                                                                
Station ID: 9452421                         PUBLICATION DATE:  07/02/2018
Name:       CHILKAT INLET                                     
            AK
NOAA Chart: 16700                           Latitude:   59° 10.2' N (  59.17000)
USGS Quad:  SKAGWAY (A-2)                   Longitude: 135° 24.0' W (-135.40000)


To reach the tidal bench marks, proceed to the eastern bank of Chilkat Inlet,
400 m (1312 ft) south of Letnikof Cove Light F1 R 4 sec.  The bench marks are
located in the vicinity on the SE to south side. The tide gauge was placed on a
small wooden platform, behind a rock cluster, 40 m (131 ft) inland from the
water's edge, approximately 6 m (20 ft) above the apparent high water.


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


                 PRIMARY BENCH MARK STAMPING:  2421 C 1998
                         DESIGNATION:          945 2421 C

MONUMENTATION:           Tidal Station disk                    VM#:        14041
AGENCY:                  National Ocean Service (NOS)          IDB PID#:        
SETTING CLASSIFICATION:  Rock outcrop                          OPUS PID:        
LATITUDE:   59° 10.2' N (  59.17000)          LONGITUDE: 135° 24.0' W (-135.40000)


The primary bench mark is a disk set on top of one of the highest points of a
prominent dark-coloured, steep-faced, mussel-encrusted, rocky ledge,
sharp-featured rock, on the eastern bank of Chilkat Inlet,  320 m (1050 ft)
south of Letnikof Cove Light F1 R 4 sec, 66 m (216 ft) NW (290 degrees magnetic)
from bench mark 2421 B 1998, 10 m (33 ft) inland of the water's edge, and 2.50 m
(8.2 ft) above the apparent high water line.

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

                                                                                
Station ID: 9452421                         PUBLICATION DATE:  07/02/2018
Name:       CHILKAT INLET                                     
            AK
NOAA Chart: 16700                           Latitude:   59° 10.2' N (  59.17000)
USGS Quad:  SKAGWAY (A-2)                   Longitude: 135° 24.0' W (-135.40000)


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


                         BENCH MARK STAMPING:  2421 A 1998
                         DESIGNATION:          945 2421 A

MONUMENTATION:           Tidal Station disk                    VM#:        14039
AGENCY:                  National Ocean Service (NOS)          IDB PID#:        
SETTING CLASSIFICATION:  Rock outcrop                          OPUS PID:        
LATITUDE:   59° 10.2' N (  59.17000)          LONGITUDE: 135° 24.0' W (-135.40000)


The bench mark is a disk set on top of a distinctive, flat, light-coloured, 1m x
1 m x 1 m (4 ft x 3 ft x 2 ft) rock on the eastern bank of Chilkat Inlet, 400 m
(1312 ft) south of Letnikof Cove Light F1 R 4 sec, along a relatively flat
section shore heavily strewn with small boulders and drift wood and sparsely
covered with tall grass, 100 m (328 ft) north of an isolated waterfront house,
39 m (128 ft) SE (60 degrees magnetic) from bench mark 2421 B 1998, 30 m (98 ft)
inland from the waterline, and 2 m (7 ft) away from the treeline.



                         BENCH MARK STAMPING:  2421 B 1998
                         DESIGNATION:          945 2421 B

MONUMENTATION:           Tidal Station disk                    VM#:        14040
AGENCY:                  National Ocean Service (NOS)          IDB PID#:        
SETTING CLASSIFICATION:  Rock outcrop                          OPUS PID:        
LATITUDE:   59° 10.2' N (  59.17000)          LONGITUDE: 135° 24.0' W (-135.40000)


The bench mark is a disk set on top of a distinctive, flat, light-coloured, 1m x
1 m x 1 m (4 ft x 3 ft x 2 ft) rock on the eastern bank of Chilkat Inlet, 400 m
(1312 ft) south of Letnikof Cove Light F1 R 4 sec, along a relatively flat
section shore heavily strewn with small boulders and drift wood and sparsely
covered with tall grass,  100 m (328 ft) north of an isolated waterfront house,
39 m (128 ft) NW (300 degrees magnetic) from bench mark 2421 A 1998, 30 m (98
ft) inland from the waterline, and 2 m (7 ft) away from the treeline.

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

                                                                                
Station ID: 9452421                         PUBLICATION DATE:  07/02/2018
Name:       CHILKAT INLET                                     
            AK
NOAA Chart: 16700                           Latitude:   59° 10.2' N (  59.17000)
USGS Quad:  SKAGWAY (A-2)                   Longitude: 135° 24.0' W (-135.40000)


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


                         BENCH MARK STAMPING:  2421 D 1998
                         DESIGNATION:          945 2421 D

MONUMENTATION:           Tidal Station disk                    VM#:        14042
AGENCY:                  National Ocean Service (NOS)          IDB PID#:        
SETTING CLASSIFICATION:  Rock outcrop                          OPUS PID#: BBDX55
LATITUDE:   59° 10.2' N (  59.17000)          LONGITUDE: 135° 24.0' W (-135.40000)


The bench mark is a disk set on top of a low-lying flat 1 m x 1 m x 0.3 m (2 ft
x 3 ft x 1 ft) rock located on the eastern bank of Chilkat Inlet,  290 m (951
ft) SSE of Letnikof Cove Light F1 R 4 sec, on a boulder strewn section of beach
just north of the prominent, dark-coloured, steep-faced, mussel-encrusted rocky
ledge, 65 m (213 ft) NE (010 degrees magnetic) from bench mark 2421 C 1998, and
8 m (26 ft) inland of the apparent high water line.



                         BENCH MARK STAMPING:  2421 E 1998
                         DESIGNATION:          945 2421 E

MONUMENTATION:           Tidal Station disk                    VM#:        14043
AGENCY:                  National Ocean Service (NOS)          IDB PID#:        
SETTING CLASSIFICATION:  Rock outcrop                          OPUS PID#: BBDX54
LATITUDE:   59° 10.2' N (  59.17000)          LONGITUDE: 135° 24.0' W (-135.40000)


The bench mark is a disk set on top of a low-lying flat 1 m x 1 m x 0.3 m (2 ft
x 3 ft x 1 ft) rock located on the eastern bank of Chilkat Inlet,  235 m (771
ft) SE of Letnikof Cove Light F1 R 4 sec, on a boulder strewn section of beach
just north of the prominent, dark-coloured, steep-faced, mussel-encrusted rocky
ledge,  56 m (184 ft) NW (340 degrees magnetic) from bench mark 2421 D 1998, 15
m (49 ft) inland of the apparent high water line, and 10 m (33 ft) below the
treeline.

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

                                                                                
Station ID: 9452421                         PUBLICATION DATE:  07/02/2018
Name:       CHILKAT INLET                                     
            AK
NOAA Chart: 16700                           Latitude:   59° 10.2' N (  59.17000)
USGS Quad:  SKAGWAY (A-2)                   Longitude: 135° 24.0' W (-135.40000)


                            T I D A L   D A T U M S 


Tidal datums at CHILKAT INLET based on:

     LENGTH OF SERIES:      30 DAYS
     TIME PERIOD:           May 15 1998 - June 14 1998
     TIDAL EPOCH:           2012-2016
     CONTROL TIDE STATION:  9452400 SKAGWAY, TAIYA INLET


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

     MEAN HIGHER HIGH WATER                     MHHW   =  5.021
     MEAN HIGH WATER                            MHW    =  4.713
     MEAN SEA LEVEL                             MSL    =  2.639
     MEAN TIDE LEVEL                            MTL    =  2.598
     MEAN LOW WATER                             MLW    =  0.482
     MEAN LOWER LOW WATER                       MLLW   =  0.000

North American Vertical Datum (NAVD88)

Bench Mark Elevation Information                In METERS above:

     Stamping or Designation                    MLLW        MHW

     2421 C 1998                                 6.457    1.743
     2421 A 1998                                 7.345    2.632
     2421 B 1998                                 7.768    3.055
     2421 D 1998                                 6.336    1.622
     2421 E 1998                                 7.311    2.597


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

                                                                                
Station ID: 9452421                         PUBLICATION DATE:  07/02/2018
Name:       CHILKAT INLET                                     
            AK
NOAA Chart: 16700                           Latitude:   59° 10.2' N (  59.17000)
USGS Quad:  SKAGWAY (A-2)                   Longitude: 135° 24.0' W (-135.40000)


                             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.