U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Datums Page Page 1 of 5
Station ID: 9450364 PUBLICATION DATE: 02/09/2009
Name: HYDABURG, SUKKWAN STRAIT
AK
NOAA Chart: 17431 Latitude: 55° 12.1' N ( 55.20169)
USGS Quad: CRAIG (A-3) Longitude: 132° 49.4' W (-132.82300)
To reach the bench marks from Hydaburg, AK begin in Hydaburg on Union Street,
proceed south to the end of the street, continue in a southerly direction past
two warehouse buildings and to the Hydaburg city pier. The tide staff was
located on the western face of the pier, on the pier extension where the Federal
Aviation Association (FAA) Automated Surface Observing System (ASOS) station is
positioned approximately 70.00 m (229.66 ft) from the primary bench mark. The
primary bench mark is located on the northerly side of the pier where the road
gravel intersects with the cement comprising the pier, set flush in concrete.
The other four bench marks are located along the shoreline in prominent rocks to
the east of the pier.
T I D A L B E N C H M A R K S
PRIMARY BENCH MARK STAMPING: 945 0364 C 2008
DESIGNATION: 945 0364 C
MONUMENTATION: Tidal Station disk VM#: 18968
AGENCY: National Ocean Service (NOS) IDB PID#:
SETTING CLASSIFICATION: Concrete pier OPUS PID:
LATITUDE: 55° 12.1' N ( 55.20222) LONGITUDE: 132° 49.3' W (-132.82167)
The primary bench mark is a disk set flush in concrete on the Hydaburg city pier
on the northern end, 150.00 m (492.0 ft) bearing 057 T from the large shed at
the southern end of the pier, 20.00 m (65.6 ft) bearing 207 T from the tan
warehouse north of the pier, 15.00 m (49.2 ft) bearing 312 T from the power
line pole immediately NE of the north end of the pier, 0.50 m (1.6 ft) from the
end of the pier, 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: 9450364 PUBLICATION DATE: 02/09/2009
Name: HYDABURG, SUKKWAN STRAIT
AK
NOAA Chart: 17431 Latitude: 55° 12.1' N ( 55.20169)
USGS Quad: CRAIG (A-3) Longitude: 132° 49.4' W (-132.82300)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 945 0364 A 2008
DESIGNATION: 945 0364 A
MONUMENTATION: Tidal Station disk VM#: 18969
AGENCY: National Ocean Service (NOS) IDB PID#:
SETTING CLASSIFICATION: Flat rock OPUS PID#: BBCM84
LATITUDE: 55° 12.1' N ( 55.20222) LONGITUDE: 132° 49.4' W (-132.82306)
The bench mark is a disk set flush in a 1 m x 1 m (3 ft x 3 ft) flat rock 177 m
( 581 ft) bearing 074 T from the large shed at the southern end of the pier,
90 m (295 ft) bearing 135 T from primary bench mark 9450364 C 2008, 90 m (295
ft) bearing 126 T from the tan shed NE of the northern end of the pier, and
0.31 m (1.02 ft) above the apparent high water line.
BENCH MARK STAMPING: 945 0364 B 2008
DESIGNATION: 945 0364 B
MONUMENTATION: Tidal Station disk VM#: 18970
AGENCY: National Ocean Service (NOS) IDB PID#:
SETTING CLASSIFICATION: Outcropping of bedrock OPUS PID:
LATITUDE: 55° 12.1' N ( 55.20222) LONGITUDE: 132° 49.3' W (-132.82167)
The bench mark is a disk set flush in a 3 m x 4 m (10 ft x 13 ft) outcropping of
bedrock, 0.76 km (0.42 nm) bearing 312 T from the closest island SE of the tide
gauge installation, 263 m ( 863 ft) bearing 077 T from the large shed at the
southern end of the pier, 160 m (525 ft) bearing 097 T from the tan shed NE
of the northern end of the pier, and 0.53 m (1.74 ft) above the apparent high
water line.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 3 of 5
Station ID: 9450364 PUBLICATION DATE: 02/09/2009
Name: HYDABURG, SUKKWAN STRAIT
AK
NOAA Chart: 17431 Latitude: 55° 12.1' N ( 55.20169)
USGS Quad: CRAIG (A-3) Longitude: 132° 49.4' W (-132.82300)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: NO 3 1955
DESIGNATION: 945 0364 Tidal 3
MONUMENTATION: Tidal Station disk VM#: 18971
AGENCY: US Coast and Geodetic Survey
(USC&GS) IDB PID#:
SETTING CLASSIFICATION: Rock OPUS PID:
LATITUDE: 55° 12.1' N ( 55.20222) LONGITUDE: 132° 49.4' W (-132.82278)
The bench mark is a disk set flush in a 2 m x 2 m (6 ft x 6 ft) rock, 205 m (673
ft) bearing 080 T from the large shed at the southern end of the pier, 140 m
(459 ft) bearing 141 T from the large tan warehouse NE of the northern end of
the pier, 30 m (98 ft) bearing 144 T from bench mark 945 0364 A, and 0.30 m
(0.98 ft) above the apparent high water line.
BENCH MARK STAMPING: POINT 1925
DESIGNATION: 945 0364 POINT 1925
MONUMENTATION: Tidal Station disk VM#: 18972
AGENCY: US Geological Survey (USGS) IDB PID#:
SETTING CLASSIFICATION: Outcropping of bedrock OPUS PID:
LATITUDE: 55° 12.1' N ( 55.20222) LONGITUDE: 132° 49.4' W (-132.82333)
The bench mark is a disk set flush in a 2 m x 3 m (6 ft x 10 ft) outcropping of
bedrock, 150 m (492 ft) bearing 074 T from the large shed at the southern end
of the pier, 100 m (328 ft) bearing 137 T from the large blue warehouse NE of
the northern end of the pier, 52 m (171 ft) bearing 048 T from a charted
prominent rock south of the bench mark, and 0.42 m (1.38 ft) above the apparent
high water line.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 4 of 5
Station ID: 9450364 PUBLICATION DATE: 02/09/2009
Name: HYDABURG, SUKKWAN STRAIT
AK
NOAA Chart: 17431 Latitude: 55° 12.1' N ( 55.20169)
USGS Quad: CRAIG (A-3) Longitude: 132° 49.4' W (-132.82300)
T I D A L D A T U M S
Tidal datums at HYDABURG, SUKKWAN STRAIT based on:
LENGTH OF SERIES: 33 DAYS
TIME PERIOD: October 8, 2008 - November 9, 2008
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 = 3.974
MEAN HIGH WATER MHW = 3.700
MEAN TIDE LEVEL MTL = 2.086
MEAN SEA LEVEL MSL = 2.075
MEAN LOW WATER MLW = 0.472
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 0364 C 2008 6.560 2.860
945 0364 A 2008 4.368 0.668
945 0364 B 2008 4.590 0.890
NO 3 1955 4.359 0.659
POINT 1925 4.480 0.780
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 5 of 5
Station ID: 9450364 PUBLICATION DATE: 02/09/2009
Name: HYDABURG, SUKKWAN STRAIT
AK
NOAA Chart: 17431 Latitude: 55° 12.1' N ( 55.20169)
USGS Quad: CRAIG (A-3) Longitude: 132° 49.4' W (-132.82300)
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.