U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Datums Page Page 1 of 8
Station ID: 9441102 PUBLICATION DATE: 12/29/2020
Name: WESTPORT, GRAYS HARBOR
WA
NOAA Chart: 18502 Latitude: 46° 54.3' N ( 46.90431)
USGS Quad: Longitude: 124° 6.3' W (-124.10508)
To reach the tidal bench marks from Aberdeen, follow State Highway 105 west for
32 km (20 mi) to Westport; at Westport turn north onto Montesano Street and
follow it to its termination at Dock Street, turn NE onto Dock Street and
continue to Westhaven Drive. The bench marks are located along Westhaven Drive
and across Westhaven Cove. The tide gauge is located on the US Coast Guard base
near the Westport Marina public boat ramp.
T I D A L B E N C H M A R K S
PRIMARY BENCH MARK STAMPING: 1102 K 2005
DESIGNATION: 944 1102 K
MONUMENTATION: Flange-encased Rod VM#: 18077
AGENCY: National Ocean Service (NOS) IDB PID:
SETTING CLASSIFICATION: Stainless steel rod OPUS PID#: BBCJ67
LATITUDE: 46° 54.2' N ( 46.90414) LONGITUDE: 124° 6.4' W (-124.10647)
The bench mark is set on the north corner of the north NYHUS Street and East
Wilson Avenue located 13.60 m (44.6 ft) NW of the centerline of East Wilson
Avenue, 1.70 (5.6 ft) north of the fire hydrant, and 0.15 m (0.49 ft) south of
the witness post. The datum point is set at ground level, being the top of a
stainless steel rod driven 25.0 m (82 ft), encased in a 5-inch PVC pipe and
aluminum access lid and concrete.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 2 of 8
Station ID: 9441102 PUBLICATION DATE: 12/29/2020
Name: WESTPORT, GRAYS HARBOR
WA
NOAA Chart: 18502 Latitude: 46° 54.3' N ( 46.90431)
USGS Quad: Longitude: 124° 6.3' W (-124.10508)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 1102 A 1982
DESIGNATION: 944 1102 A
MONUMENTATION: Tidal Station disk VM#: 8977
AGENCY: National Ocean Survey (NOS) IDB PID:
SETTING CLASSIFICATION: Concrete pad OPUS PID:
LATITUDE: 46° 54.5' N ( 46.90828) LONGITUDE: 124° 6.7' W (-124.11236)
The primary bench mark is a disk set in the east corner of the SE pad for
gasoline storage tanks at the Chevron depot at the corner of Westhaven Drive and
Dock Street, 43 m (140 ft) SE of the centerline of Dock Street, 34.29 m (112.5
ft) SW of the centerline of Westhaven Drive, 0.46 m (1.5 ft) east of the SE
tank, 0.40 m (1.3 ft) SW of the NE edge of the pad, and 0.34 m (1.1 ft) NW of
the SE edge of the pad.
BENCH MARK STAMPING: 1102 B 1982
DESIGNATION: 944 1102 B
MONUMENTATION: Tidal Station disk VM#: 8978
AGENCY: National Ocean Survey (NOS) IDB PID:
SETTING CLASSIFICATION: Concrete pad OPUS PID:
LATITUDE: 46° 54.5' N ( 46.90772) LONGITUDE: 124° 6.7' W (-124.11194)
The bench mark is a disk set in a concrete pad below fire escape stairs on the
north corner of the old U.S. Coast Guard Station building (presently Westport
Chamber of Commerce), 56 m (183 ft) SW of the centerline of Westhaven Drive,
20.30 m (66.60 ft) west of the southwest corner of the maritime museum, 12.83 m
(42.09 ft) south of the short flag pole, 4.9 m (16.08 ft) southeast of the
northeast corner of the old USCG building, 0.91 m (3.0 ft) SW of the NE edge of
the pad, and 0.55 m (1.8 ft) SE of the NW edge of the pad, and .15 m (.49 ft)
above ground level.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 3 of 8
Station ID: 9441102 PUBLICATION DATE: 12/29/2020
Name: WESTPORT, GRAYS HARBOR
WA
NOAA Chart: 18502 Latitude: 46° 54.3' N ( 46.90431)
USGS Quad: Longitude: 124° 6.3' W (-124.10508)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 1102 E 2005
DESIGNATION: 944 1102 E
MONUMENTATION: Tidal Station disk VM#: 18072
AGENCY: National Ocean Service (NOS) IDB PID:
SETTING CLASSIFICATION: Concrete monument OPUS PID:
LATITUDE: 46° 54.2' N ( 46.90411) LONGITUDE: 124° 6.3' W (-124.10564)
The bench mark is set in the NW corner of the boat house garage, 27.76 m (91.1
ft) south of the north corner of the fenceline that divides the public boat ramp
and the USCG, 8.59 m (28.2 ft) west of the NE corner of the boat house garage,
and 1.38 m (4.5 ft) east of the NW corner of the boat house garage, and set at
ground level.
BENCH MARK STAMPING: 1102 F 2005
DESIGNATION: 944 1102 F
MONUMENTATION: Tidal Station disk VM#: 18073
AGENCY: National Ocean Service (NOS) IDB PID:
SETTING CLASSIFICATION: Concrete pad OPUS PID:
LATITUDE: 46° 54.2' N ( 46.90381) LONGITUDE: 124° 6.3' W (-124.10511)
The bench mark is a disk set in the SW corner of the brick gasoline storage
building, 16.96 m (55.6 ft) NE of a light pole nearest to the sidewalk that
cuts through a grass area, 7.85 m (25.8 ft) south of a light pole in te USCG
parking lot, 1.55 m (5.1 ft) east of the sidewalk edge that is on the parking
lot side fo the USCG and 0.14 m (0.5 ft) above the parking lot level.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 4 of 8
Station ID: 9441102 PUBLICATION DATE: 12/29/2020
Name: WESTPORT, GRAYS HARBOR
WA
NOAA Chart: 18502 Latitude: 46° 54.3' N ( 46.90431)
USGS Quad: Longitude: 124° 6.3' W (-124.10508)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 1102 G 2005
DESIGNATION: 944 1102 G
MONUMENTATION: Flange-encased Rod VM#: 18074
AGENCY: National Ocean Service (NOS) IDB PID:
SETTING CLASSIFICATION: Stainless steel rod OPUS PID:
LATITUDE: 46° 54.2' N ( 46.90356) LONGITUDE: 124° 6.4' W (-124.10614)
The BM is a stainless steel deep rod driven 78 ft set in the NW corner of the
USCG base in the ground. It is 16.30 m (53.48 ft) SW of the centerline of the
USCG entry road, 1.41 m (4.63 ft) west of the light pole in the west corner of
the USCG property, 1.41 m (4.63 ft) north of the USCG fence, and encased in a 5
inch PVC pipe and aluminum access lid and concrete. It is set level with the
ground and has witness post.
BENCH MARK STAMPING: 1102 H 2005
DESIGNATION: 944 1102 H
MONUMENTATION: Flange-encased Rod VM#: 18075
AGENCY: National Ocean Service (NOS) IDB PID:
SETTING CLASSIFICATION: Stainless steel rod OPUS PID#: BBGM78
LATITUDE: 46° 54.2' N ( 46.90294) LONGITUDE: 124° 6.3' W (-124.10478)
The bench mark is located 22.88 m (75.1 ft) east of the NE corner of the wood
storage shed, 2.51 m (8.2 ft) west of the fenceline and witness post, and 1.16 m
(3.8 ft) north of the light pole nearest to the witness post and encased in a 5
inch PVC sleeve with aluminum access lid and concrete. The bench mark is
stainless steel deep rod driven 92 ft, set in the SW corner of the USCG station
and set level with the rod.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 5 of 8
Station ID: 9441102 PUBLICATION DATE: 12/29/2020
Name: WESTPORT, GRAYS HARBOR
WA
NOAA Chart: 18502 Latitude: 46° 54.3' N ( 46.90431)
USGS Quad: Longitude: 124° 6.3' W (-124.10508)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 1102 J 2005
DESIGNATION: 944 1102 J
MONUMENTATION: Tidal Station disk VM#: 18076
AGENCY: National Ocean Service (NOS) IDB PID:
SETTING CLASSIFICATION: Concrete base OPUS PID:
LATITUDE: 46° 54.2' N ( 46.90342) LONGITUDE: 124° 6.3' W (-124.10456)
The bench mark is a disk set on the NW corner of the concrete base of the USCG
radio tower, 21.55 m (70.7 ft) south of the NE corner of the USCG main office
building, 17.71 m (58.1 ft) west of the red fire hydrant, 1.68 m (5.5 ft) south
of the south leg of the radio tower, adn 0.11 m (0.4 ft) above the parking lot.
BENCH MARK STAMPING: 1102 L 2005
DESIGNATION: 944 1102 L
MONUMENTATION: Tidal Station disk VM#: 18078
AGENCY: National Ocean Service (NOS) IDB PID:
SETTING CLASSIFICATION: Loading dock OPUS PID:
LATITUDE: 46° 54.3' N ( 46.90553) LONGITUDE: 124° 6.5' W (-124.10861)
The bench mark is a disk set in the loading dock garage of the Oceans Gold Crab
Company located at 1804 North Nyhus Street Westport, WA 98595. BM is 14.10 m
(46.3 ft) east of the west corner of the Ocean Gold Crab Company building, 9.70
m (31.8 ft) SE of the centerline of the Nyhus Street, 2.14 m (7.0 ft) west of
the east corner of the Oceans Gold Crab Company, and 0.39 m (1.3 ft) above the
street.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 6 of 8
Station ID: 9441102 PUBLICATION DATE: 12/29/2020
Name: WESTPORT, GRAYS HARBOR
WA
NOAA Chart: 18502 Latitude: 46° 54.3' N ( 46.90431)
USGS Quad: Longitude: 124° 6.3' W (-124.10508)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 1102 M 2005
DESIGNATION: 944 1102 M
MONUMENTATION: Tidal Station disk VM#: 18079
AGENCY: National Ocean Service (NOS) IDB PID:
SETTING CLASSIFICATION: Garage door OPUS PID:
LATITUDE: 46° 54.4' N ( 46.90717) LONGITUDE: 124° 6.7' W (-124.11103)
The bench mark is a disk set in the garage door way for the Westport Marina
(Port of Grays Harbor), 14.10 m (46.3 ft) NE of the centerline of Nyhus Street,
10.40 m (34.1 ft) SE of the NW corner of the Westport Marina (Port of Grays
Harbor) building, 0.74 m (2.4 ft) NW of the SE corner of the Westport Marina
(Port of Grays Harbor) building. Set level with Nyhus Street.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 7 of 8
Station ID: 9441102 PUBLICATION DATE: 12/29/2020
Name: WESTPORT, GRAYS HARBOR
WA
NOAA Chart: 18502 Latitude: 46° 54.3' N ( 46.90431)
USGS Quad: Longitude: 124° 6.3' W (-124.10508)
T I D A L D A T U M S
Tidal datums at WESTPORT, GRAYS HARBOR based on:
LENGTH OF SERIES: 11 YEARS
TIME PERIOD: 1/07-12/09, 10/10 -9/14, 7/15-6/19
TIDAL EPOCH: 1983-2001
CONTROL TIDE STATION: 9440910 TOKE POINT, WILLAPA BAY
Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in METERS:
HIGHEST OBSERVED WATER LEVEL (11/24/2011) = 3.855
MEAN HIGHER HIGH WATER MHHW = 2.787
MEAN HIGH WATER MHW = 2.561
MEAN TIDE LEVEL MTL = 1.493
MEAN SEA LEVEL MSL = 1.484
MEAN LOW WATER MLW = 0.426
North American Vertical Datum NAVD88 = 0.343
MEAN LOWER LOW WATER MLLW = 0.000
LOWEST OBSERVED WATER LEVEL (05/07/2008) = -1.100
North American Vertical Datum (NAVD88)
Bench Mark Elevation Information In METERS above:
Stamping or Designation MLLW MHW
1102 K 2005 4.690 2.129
1102 A 1982 4.676 2.115
1102 B 1982 5.186 2.625
1102 E 2005 5.433 2.872
1102 F 2005 5.094 2.533
1102 G 2005 5.017 2.456
1102 H 2005 4.932 2.371
1102 J 2005 5.697 3.136
1102 L 2005 5.313 2.752
1102 M 2005 4.993 2.432
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 8 of 8
Station ID: 9441102 PUBLICATION DATE: 12/29/2020
Name: WESTPORT, GRAYS HARBOR
WA
NOAA Chart: 18502 Latitude: 46° 54.3' N ( 46.90431)
USGS Quad: Longitude: 124° 6.3' W (-124.10508)
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.