U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Datums Page Page 1 of 5
Station ID: 9440846 PUBLICATION DATE: 05/01/2003
Name: BAY CENTER
WA
NOAA Chart: 18504 Latitude: 46° 37.4' N ( 46.62330)
USGS Quad: NEMAH Longitude: 123° 56.7' W (-123.94500)
To reach the tidal bench marks from South Bend, proceed south on U.S. Highway
101 for 21 km (13 mi), then after crossing over Palix River, turn right at a
sign for Bay Center then proceed NW on Bay Center Dike Road for 3.9 km (2.4 mi)
to a bridge over Bay Center Channel. The bench marks are located near the
bridge. The tide gage and staff were on the Harbor Bell Inc., wharf along Palix
River, 0.6 km (0.4 mi) SE of the bridge.
T I D A L B E N C H M A R K S
PRIMARY BENCH MARK STAMPING: TIDAL NO 1 1954
DESIGNATION: 944 0846 TIDAL 1
MONUMENTATION: Tidal Station disk VM#: 8961
AGENCY: US Coast and Geodetic Survey
(USC&GS) IDB PID#:
SETTING CLASSIFICATION: Concrete pavement OPUS PID:
LATITUDE: 46° 37.4' N ( 46.62330) LONGITUDE: 123° 56.7' W (-123.94500)
The primary bench mark is a disk set in a 0.61 m (2.0 ft) wide concrete gas pump
island in front of a three-story corrugated tin walled, wood frame building, 69
m (225 ft) east of the intersection of Bay Center Dike Road and Rhodesia
Beach-Bay Center Highway, 8 m (26 ft) north of the centerline of Bay Center Dike
Road, and 1.37 m (4.5 ft) south of the south face of the building.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 2 of 5
Station ID: 9440846 PUBLICATION DATE: 05/01/2003
Name: BAY CENTER
WA
NOAA Chart: 18504 Latitude: 46° 37.4' N ( 46.62330)
USGS Quad: NEMAH Longitude: 123° 56.7' W (-123.94500)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 8 1944
DESIGNATION: 944 0846 TIDAL 8
MONUMENTATION: Tidal Station disk VM#: 8963
AGENCY: US Coast and Geodetic Survey
(USC&GS) IDB PID#:
SETTING CLASSIFICATION: Concrete foundation OPUS PID:
LATITUDE: 46° 37.4' N ( 46.62330) LONGITUDE: 123° 56.7' W (-123.94500)
The bench mark is a disk set in the SE end of an abandoned concrete foundation
in front of a one-story concrete block foundation building (Penguin Inn Cafe and
Tavern) at the intersection of Rhodesia Beach Highway and Bay Center Dike Road,
23 m (77 ft) SE of the SE corner of the bridge, 13 m (42 ft) north of the
centerline of Bay Center Dike Road, and 1.37 m (4.5 ft) SW of the SW building
face.
BENCH MARK STAMPING: 0846 A 1982
DESIGNATION: 944 0846 A
MONUMENTATION: Tidal Station disk VM#: 8964
AGENCY: National Ocean Survey (NOS) IDB PID#:
SETTING CLASSIFICATION: Concrete wing wall OPUS PID:
LATITUDE: 46° 37.4' N ( 46.62330) LONGITUDE: 123° 56.7' W (-123.94500)
The bench mark is a disk set in the SW concrete wing wall of the bridge over Bay
Center Channel, 6.00 m (19.7 ft) west of the centerline of the bridge, and 0.15
m (0.5 ft) east of the west end of the wing wall.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 3 of 5
Station ID: 9440846 PUBLICATION DATE: 05/01/2003
Name: BAY CENTER
WA
NOAA Chart: 18504 Latitude: 46° 37.4' N ( 46.62330)
USGS Quad: NEMAH Longitude: 123° 56.7' W (-123.94500)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 0846 B 1982
DESIGNATION: 944 0846 B
MONUMENTATION: Tidal Station disk VM#: 8965
AGENCY: National Ocean Survey (NOS) IDB PID#:
SETTING CLASSIFICATION: Concrete retaining wall OPUS PID:
LATITUDE: 46° 37.4' N ( 46.62330) LONGITUDE: 123° 56.7' W (-123.94500)
The bench mark is a disk set in the east end of a retaining wall in front of a
red one-story wooden house NE of the NE corner of the bridge over Bay Center
Channel, 9 m (29 ft) south of the centerline of the east-west road, 3.44 m (11.3
ft) north of the north face of the wooden house, and 1 m (3 ft) west of the east
edge of the retaining wall.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 4 of 5
Station ID: 9440846 PUBLICATION DATE: 05/01/2003
Name: BAY CENTER
WA
NOAA Chart: 18504 Latitude: 46° 37.4' N ( 46.62330)
USGS Quad: NEMAH Longitude: 123° 56.7' W (-123.94500)
T I D A L D A T U M S
Tidal datums at BAY CENTER based on:
LENGTH OF SERIES: 1 MONTH
TIME PERIOD: June 1982 - June 1982
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:
MEAN HIGHER HIGH WATER MHHW = 2.806
MEAN HIGH WATER MHW = 2.583
MEAN SEA LEVEL MSL = 1.529
MEAN TIDE LEVEL MTL = 1.506
MEAN LOW WATER MLW = 0.429
MEAN LOWER LOW WATER MLLW = 0.000
North American Vertical Datum (NAVD88)
Bench Mark Elevation Information In METERS above:
Stamping or Designation MLLW MHW
TIDAL NO 1 1954 3.966 1.383
8 1944 4.004 1.421
0846 A 1982 4.697 2.114
0846 B 1982 9.987 7.404
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 5 of 5
Station ID: 9440846 PUBLICATION DATE: 05/01/2003
Name: BAY CENTER
WA
NOAA Chart: 18504 Latitude: 46° 37.4' N ( 46.62330)
USGS Quad: NEMAH Longitude: 123° 56.7' W (-123.94500)
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.