U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Datums Page Page 1 of 6
Station ID: 9450618 PUBLICATION DATE: 03/06/2017
Name: SHINAKU INLET
AK
NOAA Chart: 17405 Latitude: 55° 35.6' N ( 55.59292)
USGS Quad: CRAIG (C-4) Longitude: 133° 9.1' W (-133.15200)
To reach the bench marks from Sitka, AK via boat, proceed SSW through Sitka
Sound for 25.0 km (13.5 nm) to Biorka Island, then turn SE and proceed 100.0 km
(54.0 nm) to Cape Ommaney, turn ESE and proceed 44.4 km (24.0 nm) through Cape
Decision to Warren Channel, turn SSE and proceed through Warren Channel for 27.8
km (15.0 nm) to Cape Lynch, turn SE and proceed 15.0 km (8.1 nm) through Bocas
de Finas to Pt. Disconocida, then turn SE and proceed 16.0 km (9.34 nm) across
Gulf of Esquibel, proceed SE 5.00 km (3.11 nm) through San Christoval Channel to
San Christoval Rock, turn ENE and proceed 10.6 km (5.9 nm) into Shinuku Inlet.
The tide gauge site is located 4.78 km (2.58 nm) bearing 324 T from Klawock,
AK. The tide staff was located on the north end of the islets and the gauge and
benchmarks were installed leading south along the island rocks. The bench marks
are located on the northern half of a large islet cluster, close to the tree
line.
T I D A L B E N C H M A R K S
PRIMARY BENCH MARK STAMPING: 945 0618 A 2008
DESIGNATION: 945 0618 A
MONUMENTATION: Tidal Station disk VM#: 18975
AGENCY: National Ocean Service (NOS) IDB PID#:
SETTING CLASSIFICATION: Bedrock OPUS PID:
LATITUDE: 55° 35.6' N ( 55.59306) LONGITUDE: 133° 9.1' W (-133.15167)
The primary bench mark is a disk set flush in bedrock 0.40 km (0.22 nm) bearing
086 T (064 M) from rocky islet at NW end of Shinaku Inlet, 125.00 m (410.1 ft)
bearing 280 T (258 M) from rock off the north shore of the SE islet, 85.00 m
(278.9 ft) bearing 231 T (209 M) from rock off from northern islet on which
the staff resides, north shore of SE islet, 7.00 m (23 ft) from the tree line,
and 0.40 m (1.3 ft) above the apparent high water line.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 2 of 6
Station ID: 9450618 PUBLICATION DATE: 03/06/2017
Name: SHINAKU INLET
AK
NOAA Chart: 17405 Latitude: 55° 35.6' N ( 55.59292)
USGS Quad: CRAIG (C-4) Longitude: 133° 9.1' W (-133.15200)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 945 0618 B 2008
DESIGNATION: 945 0618 B
MONUMENTATION: Tidal Station disk VM#: 18976
AGENCY: National Ocean Service (NOS) IDB PID#:
SETTING CLASSIFICATION: Bedrock OPUS PID:
LATITUDE: 55° 35.6' N ( 55.59278) LONGITUDE: 133° 9.1' W (-133.15111)
The bench mark is a disk set flush in bedrock 0.83 km (0.45 nm) bearing 229 T
(252 M) from rocky islet at NE end of Shinaku Inlet, 95.00 m (311.68 ft)
bearing 253 T (275 M) from the rock off the northern shore of the southern
islet, 80.00 m (262.46 ft) bearing 141 T (163 M) from the northern shore of the
northwestern islet, 15.00 m (49.2 ft) from the tree line on the central islet,
and -0.33 m (-1.08 ft) below the apparent high water line.
BENCH MARK STAMPING: 945 0618 C 2008
DESIGNATION: 945 0618 C
MONUMENTATION: Tidal Station disk VM#: 18977
AGENCY: National Ocean Service (NOS) IDB PID#:
SETTING CLASSIFICATION: Bedrock OPUS PID:
LATITUDE: 55° 35.5' N ( 55.59222) LONGITUDE: 133° 9.1' W (-133.15139)
The bench mark is a disk set flush in bedrock 1.50 km (0.81 nm) bearing 349 T
(011 M) from dock on the southeastern shore of Shinaku Inlet, 1.11 km (0.60 nm)
bearing 308 T (330 M) from prominent cliffs on the shore to the SE in Shinaku
Inlet, 0.42 km (0.23 nm) bearing 094 T (116 M) from rocky islet NE of the
islet where the gauge is installed, 20.00 m (65.6 ft) from the tree line on the
southern islet, and -0.35 m (-1.15 ft) below the apparent high water line.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 3 of 6
Station ID: 9450618 PUBLICATION DATE: 03/06/2017
Name: SHINAKU INLET
AK
NOAA Chart: 17405 Latitude: 55° 35.6' N ( 55.59292)
USGS Quad: CRAIG (C-4) Longitude: 133° 9.1' W (-133.15200)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 945 0618 D 2008
DESIGNATION: 945 0618 D
MONUMENTATION: Tidal Station disk VM#: 18978
AGENCY: National Ocean Service (NOS) IDB PID#:
SETTING CLASSIFICATION: Bedrock OPUS PID:
LATITUDE: 55° 35.6' N ( 55.59278) LONGITUDE: 133° 9.1' W (-133.15194)
The bench mark is a disk set flush in bedrock 1.50 km (0.81 nm) bearing 349 T
(011 M) from dock on the southeastern shore of Shinaku Inlet, 0.40 km (0.22 nm)
bearing 081 T (103 M) from rocky islet NE of the islet where the gauge is
installed, 110.00 m (360.9 ft) bearing 332 T (254 M) from the rock NE of the
central islet, 20.00 m (65.6 ft) from the tree line on the southern islet, -0.12
m (-0.39 ft) below the apparent high water line.
BENCH MARK STAMPING: 945 0618 E 2008
DESIGNATION: 945 0618 E
MONUMENTATION: Tidal Station disk VM#: 18979
AGENCY: National Ocean Service (NOS) IDB PID#:
SETTING CLASSIFICATION: Bedrock OPUS PID:
LATITUDE: 55° 35.6' N ( 55.59250) LONGITUDE: 133° 9.0' W (-133.15083)
The bench mark is a disk set flush in bedrock 0.70 km (0.38 nm) bearing 227 T
(249 M) from rocky islet at NE end of Shinaku Inlet, 120.00 m (393.7 ft)
bearing 155 T (177 M) from the northern shore of the northwestern islet, 80.00 m
(262.46 ft) bearing 261 T (283 M) from the rock off the northern shore of the
southern islet, 5.00 m (16.4 ft) from the tree line on the SW islet, and -0.36 m
(1.18 ft) below the apparent high water line.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 4 of 6
Station ID: 9450618 PUBLICATION DATE: 03/06/2017
Name: SHINAKU INLET
AK
NOAA Chart: 17405 Latitude: 55° 35.6' N ( 55.59292)
USGS Quad: CRAIG (C-4) Longitude: 133° 9.1' W (-133.15200)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 1927
DESIGNATION: 945 0618 TIDAL 1927
MONUMENTATION: Tidal Station disk VM#: 18980
AGENCY: US Coast and Geodetic Survey
(USC&GS) IDB PID#:
SETTING CLASSIFICATION: Bedrock OPUS PID:
LATITUDE: 55° 35.6' N ( 55.59288) LONGITUDE: 133° 9.1' W (-133.15182)
The bench mark is a disk set flush in bedrock 0.35 km (0.19 nm) bearing 079 T
(059 M) from eastern islet on within Shinaku Inlet, 205.0 m (672.4 ft) bearing
233 T (213 M) from rocky islet at NE end of Shinaku Inlet, 75.00 m (246.0 ft)
bearing 277 T (257 M) from rock off north shore of SE islet, 12.00 m (39.4 ft)
from the tree line, and 0.22 m (0.72 ft) above the apparent high water line.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 5 of 6
Station ID: 9450618 PUBLICATION DATE: 03/06/2017
Name: SHINAKU INLET
AK
NOAA Chart: 17405 Latitude: 55° 35.6' N ( 55.59292)
USGS Quad: CRAIG (C-4) Longitude: 133° 9.1' W (-133.15200)
T I D A L D A T U M S
Tidal datums at SHINAKU INLET based on:
LENGTH OF SERIES: 29 DAYS
TIME PERIOD: October 11, 2008 - November 8, 2008
TIDAL EPOCH: 1983-2001
CONTROL TIDE STATION: 9451600 SITKA, BARONOF ISLAND, SITKA SOUND
Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in METERS:
MEAN HIGHER HIGH WATER MHHW = 3.077
MEAN HIGH WATER MHW = 2.812
MEAN TIDE LEVEL MTL = 1.614
MEAN SEA LEVEL MSL = 1.613
MEAN LOW WATER MLW = 0.416
MEAN LOWER LOW WATER MLLW = 0.000
North American Vertical Datum (NAVD88)
Bench Mark Elevation Information In METERS above:
Stamping or Designation MLLW MHW
945 0618 A 2008 3.976 1.163
945 0618 B 2008 3.245 0.433
945 0618 C 2008 3.228 0.415
945 0618 D 2008 3.455 0.642
945 0618 E 2008 3.211 0.399
1927 3.795 0.983
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 6 of 6
Station ID: 9450618 PUBLICATION DATE: 03/06/2017
Name: SHINAKU INLET
AK
NOAA Chart: 17405 Latitude: 55° 35.6' N ( 55.59292)
USGS Quad: CRAIG (C-4) Longitude: 133° 9.1' W (-133.15200)
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.