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National Ocean Service
Datums Page Page 1 of 8
Station ID: 9431647 PUBLICATION DATE: 03/19/2021
Name: PORT ORFORD, PACIFIC OCEAN
OR
NOAA Chart: 18589 Latitude: 42° 44.3' N ( 42.73900)
USGS Quad: PORT ORFORD Longitude: 124° 29.9' W (-124.49830)
To reach the tidal bench marks from U.S. Highway 101 (6th Street) in Port
Orford, proceed south on Harbor Drive towards the port of Port Orford. The road
turns to the west and ends on the Port Orford wharf. The bench marks are located
on and near the wharf and jetty. The tide gauge is located at the east corner of
the wharf.
T I D A L B E N C H M A R K S
PRIMARY BENCH MARK STAMPING: NO 6 1937
DESIGNATION: 943 1647 TIDAL 6
MONUMENTATION: Tidal Station disk VM#: 1035
AGENCY: US Coast and Geodetic Survey
(USC&GS) IDB PID#: OA0075
SETTING CLASSIFICATION: Rock outcrop OPUS PID:
LATITUDE: 42° 44.4' N ( 42.74058) LONGITUDE: 124° 30.0' W (-124.49922)
The primary bench mark is a disk set flush in a large, gently curved outcropping
of bedrock, 37 m (120 ft) north of the Port Orford Municipal Pier, 8 m (25 ft)
north of the north face of a prominent pinnacle rock, and 3.20 m (10.5 ft) east
of the SE corner of Premium Pacific Seafoods.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 2 of 8
Station ID: 9431647 PUBLICATION DATE: 03/19/2021
Name: PORT ORFORD, PACIFIC OCEAN
OR
NOAA Chart: 18589 Latitude: 42° 44.3' N ( 42.73900)
USGS Quad: PORT ORFORD Longitude: 124° 29.9' W (-124.49830)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: NO 9 1974
DESIGNATION: 943 1647 TIDAL 9
MONUMENTATION: Tidal Station disk VM#: 1037
AGENCY: National Ocean Survey (NOS) IDB PID#: OA0785
SETTING CLASSIFICATION: Rock outcrop OPUS PID:
LATITUDE: 42° 44.4' N ( 42.73961) LONGITUDE: 124° 30.0' W (-124.49989)
The bench mark is a disk set flush in the bedrock base of a high cliff west of
Port Orford Municipal Pier, 91 m (300 ft) west of bench mark Lead 1961, 36 m
(118 ft) west of the NW corner of a building labeled "The Dock", and 7.77 m
(25.5 ft) NW of bench mark 1647 G 1977, and 5.87 m (19.25 ft) SW of the corner
of the cement edge of the parking lot.
BENCH MARK STAMPING: 1647 G 1977
DESIGNATION: 943 1647 G TIDAL
MONUMENTATION: Tidal Station disk VM#: 1038
AGENCY: National Ocean Survey (NOS) IDB PID#: OA0786
SETTING CLASSIFICATION: Rock outcrop OPUS PID:
LATITUDE: 42° 44.4' N ( 42.73953) LONGITUDE: 124° 30.0' W (-124.49981)
The bench mark is a disk, set in an irregular shaped 3.05 m (10.0 ft) rock
outcropping, 33.22 m (109.0 ft) west of the bait and snack bar building labeled
"The Dock," 12.31 m (40.4 ft) south of the SW corner of a cinder block
transformer building, 7.68 m (25.2 ft) SE of bench mark NO 9 1974, and 0.6 m
(2.0 ft) above the paved parking area.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 3 of 8
Station ID: 9431647 PUBLICATION DATE: 03/19/2021
Name: PORT ORFORD, PACIFIC OCEAN
OR
NOAA Chart: 18589 Latitude: 42° 44.3' N ( 42.73900)
USGS Quad: PORT ORFORD Longitude: 124° 29.9' W (-124.49830)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: TIDAL BM 1647 J 1978
DESIGNATION: 943 1647 J TIDAL
MONUMENTATION: Tidal Station disk VM#: 1039
AGENCY: National Ocean Survey (NOS) IDB PID#: OA0788
SETTING CLASSIFICATION: Rock outcrop OPUS PID:
LATITUDE: 42° 44.3' N ( 42.73894) LONGITUDE: 124° 30.0' W (-124.49933)
The bench mark is a disk set in bedrock, 73.15 m (240.0 ft) south of bench mark
1647 G 1977, 38.10 m (125.0 ft) west of a metal post with a green warning sign
in a concrete block, 38.10 m (125.0 ft) NW of bench mark TIDAL BM 1647 K 1978,
10.79 m (35.4 ft) NW of bench mark Lead 1961, 7.35 m (24.1 ft) east of exposed
pipe in a concrete patch, and 3.70 m (12.1 ft) south of the south edge of
concrete patch.
BENCH MARK STAMPING: TIDAL BM 1647 K 1978
DESIGNATION: 943 1647 K TIDAL
MONUMENTATION: Tidal Station disk VM#: 1040
AGENCY: National Ocean Survey (NOS) IDB PID#: OA0789
SETTING CLASSIFICATION: Rock outcrop OPUS PID:
LATITUDE: 42° 44.3' N ( 42.73867) LONGITUDE: 124° 29.9' W (-124.49908)
The bench mark is a disk set in a rock outcrop, 68.58 m (225.0 ft) SE of the end
of an asphalt road, 31.39 m (103.0 ft) SE of bench mark Lead (1981), and 16.76 m
(55.0 ft) west from a 1.37 m (4.5 ft) tall, 6-inch diameter steel pipe with a
green warning sign in a concrete block.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 4 of 8
Station ID: 9431647 PUBLICATION DATE: 03/19/2021
Name: PORT ORFORD, PACIFIC OCEAN
OR
NOAA Chart: 18589 Latitude: 42° 44.3' N ( 42.73900)
USGS Quad: PORT ORFORD Longitude: 124° 29.9' W (-124.49830)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 1647 N 1983
DESIGNATION: 943 1647 N TIDAL
MONUMENTATION: Tidal Station disk VM#: 1043
AGENCY: National Ocean Service (NOS) IDB PID#: OA0787
SETTING CLASSIFICATION: Rock outcrop OPUS PID:
LATITUDE: 42° 44.4' N ( 42.73931) LONGITUDE: 124° 30.0' W (-124.49978)
The bench mark is a disk set in a rock outcrop, 56.39 m (185.0 ft) NW of bench
mark 1647 J 1978, 48.46 m (159.0 ft) SW of the south corner of wooden building
labeled "The Dock", 27.74 m (91.0 ft) south of bench mark 1647 G 1977, and 6.10
m (20.0 ft) east of the SW edge of bedrock outcrop.
BENCH MARK STAMPING: LEAD 1961
DESIGNATION: 943 1647 TIDAL LEAD
MONUMENTATION: Bench Mark disk VM#: 1044
AGENCY: US Army Corps of Engineers (USE) IDB PID#: OA0790
SETTING CLASSIFICATION: Rock outcrop OPUS PID#: OA0790
LATITUDE: 42° 44.3' N ( 42.73903) LONGITUDE: 124° 30.0' W (-124.49925)
The bench mark is a disk set in a rock outcrop, 85.04 m (279.0 ft) SE of bench
mark 1647 G 1977, 31.39 m (103.0 ft) NW of bench mark TIDAL BM 1647 K 1978,
30.78 m (101.0 ft) south of the southern-most of two 1.8 m (5.9 ft) high, 2-inch
diameter steel pipes set in the low concrete wall of the SW entrance to the
wooden dock, 30.48 m (100.0 ft) NW of a 1.37 m (4.5 ft) high, 6-inch diameter
steel pipe with a green warning sign set in a concrete block, and 10.79 m (35.4
ft) SE of bench mark TIDAL BM 1647 J 1978.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 5 of 8
Station ID: 9431647 PUBLICATION DATE: 03/19/2021
Name: PORT ORFORD, PACIFIC OCEAN
OR
NOAA Chart: 18589 Latitude: 42° 44.3' N ( 42.73900)
USGS Quad: PORT ORFORD Longitude: 124° 29.9' W (-124.49830)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 1647 T 2002
DESIGNATION: 943 1647 T
MONUMENTATION: Tidal Station disk VM#: 16702
AGENCY: National Ocean Service (NOS) IDB PID:
SETTING CLASSIFICATION: Concrete pier deck OPUS PID:
LATITUDE: 42° 44.4' N ( 42.73964) LONGITUDE: 124° 29.9' W (-124.49853)
The bench mark is a disk set flush in concrete deck on the east of the pier,
3.70 m (12.1 ft) north of a large yellow crane, 0.58 m (1.9 ft) west of
north-south running section of a bullrail, and 0.55 m (1.8 ft) south of
east-west running section of the bullrail.
BENCH MARK STAMPING: 1647 U 2011
DESIGNATION: 943 1647 U
MONUMENTATION: Tidal Station disk VM#: 19985
AGENCY: National Ocean Service (NOS) IDB PID:
SETTING CLASSIFICATION: Concrete bull rail OPUS PID:
LATITUDE: 42° 44.4' N ( 42.74014) LONGITUDE: 124° 29.9' W (-124.49875)
The bench mark is a disk set flush at the north end of the concrete bull rail on
the north east side of the Port Orford pier, 42.9 m (140.7 ft) NW of the walkway
entrance ramp to the floating dock, 6.66 m (21.9 ft) SSE of a fire hydrant, 5.94
m (19.5 ft) NNE of the NE edge of the NE concrete boat parking pad, 0.205 m (0.7
ft) SE of the northern most end of the bull rail and 0.32 m (1.0 ft) above
ground level.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 6 of 8
Station ID: 9431647 PUBLICATION DATE: 03/19/2021
Name: PORT ORFORD, PACIFIC OCEAN
OR
NOAA Chart: 18589 Latitude: 42° 44.3' N ( 42.73900)
USGS Quad: PORT ORFORD Longitude: 124° 29.9' W (-124.49830)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 1647 V 2014
DESIGNATION: 943 1647 V
MONUMENTATION: Bench Mark disk VM#: 21086
AGENCY: National Ocean Service IDB PID:
SETTING CLASSIFICATION: Concrete bull rail OPUS PID:
LATITUDE: 42° 44.3' N ( 42.73889) LONGITUDE: 124° 29.9' W (-124.49834)
Bench mark is a NOS disk set in the Bullrail along the SE end of Port Orford
pier, located 22.4 m (73.5 ft) SW of a light pole, 13.5 m (44.3 ft) NE of a
light pole, 10.7 m (35.1 ft) SE of a sewer manhole and 0.46 m (1.5 ft) above the
asphalt pier surface.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 7 of 8
Station ID: 9431647 PUBLICATION DATE: 03/19/2021
Name: PORT ORFORD, PACIFIC OCEAN
OR
NOAA Chart: 18589 Latitude: 42° 44.3' N ( 42.73900)
USGS Quad: PORT ORFORD Longitude: 124° 29.9' W (-124.49830)
T I D A L D A T U M S
Tidal datums at PORT ORFORD, PACIFIC OCEAN based on:
LENGTH OF SERIES: 32 YEARS
TIME PERIOD: 01/01/1982-12/31/1998, 01/01/2003-12/31/2017
TIDAL EPOCH: 1983-2001
CONTROL TIDE STATION: 9419750 CRESCENT CITY, PACIFIC OCEAN
Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in METERS:
HIGHEST OBSERVED WATER LEVEL (02/17/1978) = 3.484
MEAN HIGHER HIGH WATER MHHW = 2.219
MEAN HIGH WATER MHW = 2.004
MEAN TIDE LEVEL MTL = 1.209
MEAN SEA LEVEL MSL = 1.198
MEAN LOW WATER MLW = 0.414
North American Vertical Datum NAVD88 = 0.124
MEAN LOWER LOW WATER MLLW = 0.000
LOWEST OBSERVED WATER LEVEL (01/12/2009) = -0.996
North American Vertical Datum (NAVD88)
Bench Mark Elevation Information In METERS above:
Stamping or Designation MLLW MHW
NO 6 1937 5.212 3.208
NO 9 1974 8.361 6.357
1647 G 1977 7.725 5.721
TIDAL BM 1647 J 1978 5.589 3.585
TIDAL BM 1647 K 1978 6.432 4.428
1647 N 1983 5.237 3.233
LEAD 1961 6.006 4.002
1647 T 2002 7.623 5.619
1647 U 2011 7.453 5.449
1647 V 2014 8.006 6.002
Foot Notes:
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 8 of 8
Station ID: 9431647 PUBLICATION DATE: 03/19/2021
Name: PORT ORFORD, PACIFIC OCEAN
OR
NOAA Chart: 18589 Latitude: 42° 44.3' N ( 42.73900)
USGS Quad: PORT ORFORD Longitude: 124° 29.9' W (-124.49830)
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.