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National Ocean Service
Datums Page Page 1 of 6
Station ID: 9446705 PUBLICATION DATE: 04/29/2004
Name: YOMAN POINT, ANDERSON ISLAND
WA
NOAA Chart: 18445 Latitude: 47° 10.8' N ( 47.18000)
USGS Quad: MCNEIL ISLAND Longitude: 122° 40.5' W (-122.67500)
To reach the tidal bench marks from Steilacoom, take the Pierce County Ferry to
Yoman Point, Anderson Island. The bench marks are near the ferry slip. The
tide gage and staff were located on the ferry pier.
T I D A L B E N C H M A R K S
PRIMARY BENCH MARK STAMPING: 6705 E 1978
DESIGNATION: 944 6705 E
MONUMENTATION: Tidal Station disk VM#: 9175
AGENCY: National Ocean Survey (NOS) IDB PID#:
SETTING CLASSIFICATION: Concrete foundation OPUS PID:
LATITUDE: 47° 10.8' N ( 47.18000) LONGITUDE: 122° 40.5' W (-122.67500)
The primary bench mark is a disk set in the NE corner of a concrete slab
adjoining a large tin shed south of Villa Beach Road, 366 m (1200 ft) SE along
Villa Beach Road from its intersection with Yoman Road, 48 m (157 ft) north of
the north front of a store and garage, 31 m (102 ft) SW of a Standard Oil sign
at the south edge of Villa Beach Road, and 14 m (46 ft) SE of the NE corner of
the tin shed.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 2 of 6
Station ID: 9446705 PUBLICATION DATE: 04/29/2004
Name: YOMAN POINT, ANDERSON ISLAND
WA
NOAA Chart: 18445 Latitude: 47° 10.8' N ( 47.18000)
USGS Quad: MCNEIL ISLAND Longitude: 122° 40.5' W (-122.67500)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 6705 D 1978
DESIGNATION: 944 6705 D
MONUMENTATION: Tidal Station disk VM#: 9174
AGENCY: National Ocean Survey (NOS) IDB PID#:
SETTING CLASSIFICATION: Concrete step OPUS PID:
LATITUDE: 47° 10.8' N ( 47.18000) LONGITUDE: 122° 40.5' W (-122.67500)
The bench mark is a disk set in top step of a set of eleven concrete steps
leading northeasterly toward the beach from Villa Beach Road, 140 m (459 ft) SE
of the intersection of Villa Beach Road and Yoman Road, 8 m (26 ft) east of a
pair of mailboxes on the south side of Villa Beach Road, and 3.75 m (12.3 ft)
east of the centerline of Villa Beach Road.
BENCH MARK STAMPING: 6705 F 1984
DESIGNATION: 944 6705 F
MONUMENTATION: Tidal Station disk VM#: 13566
AGENCY: National Ocean Service (NOS) IDB PID#:
SETTING CLASSIFICATION: Concrete bulkhead OPUS PID:
LATITUDE: 47° 10.8' N ( 47.18000) LONGITUDE: 122° 40.5' W (-122.67500)
The bench mark is a disk located at the NW end of a concrete bulkhead located at
the west side of the inshore end of the Ferry Terminal, 3 m (11 ft) NW of the
wooden stairs in the bulkhead which lead down to the beach, and 1 m (4 ft) NW of
power pole C30.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 3 of 6
Station ID: 9446705 PUBLICATION DATE: 04/29/2004
Name: YOMAN POINT, ANDERSON ISLAND
WA
NOAA Chart: 18445 Latitude: 47° 10.8' N ( 47.18000)
USGS Quad: MCNEIL ISLAND Longitude: 122° 40.5' W (-122.67500)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 6705 G 1984
DESIGNATION: 944 6705 G
MONUMENTATION: Tidal Station disk VM#: 13567
AGENCY: National Ocean Service (NOS) IDB PID#:
SETTING CLASSIFICATION: Concrete bulkhead OPUS PID:
LATITUDE: 47° 10.8' N ( 47.18000) LONGITUDE: 122° 40.5' W (-122.67500)
The bench mark is a disk set at the SE end of a concrete bulkhead at the west
inshore end of the Ferry Terminal, 6 m (19 ft) SE of power pole # C30, and 3 m
(11 ft) SE of a stairway leading to the beach in the center of the bulkhead.
BENCH MARK STAMPING: 6705 H 1996
DESIGNATION: 944 6705 H
MONUMENTATION: Tidal Station disk VM#: 13568
AGENCY: National Ocean Service (NOS) IDB PID#:
SETTING CLASSIFICATION: Concrete walkway OPUS PID:
LATITUDE: 47° 10.8' N ( 47.18000) LONGITUDE: 122° 40.5' W (-122.67500)
The bench mark is a disk set in the concrete walkway leading to the Ferry
Terminal loading area building, 15 m (49 ft) NNW of the SE corner of the
building at the end of the Ferry Terminal, and 10 m (33 ft) SSE of the edge of
the west side of the Ferry Terminal loading ramp.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 4 of 6
Station ID: 9446705 PUBLICATION DATE: 04/29/2004
Name: YOMAN POINT, ANDERSON ISLAND
WA
NOAA Chart: 18445 Latitude: 47° 10.8' N ( 47.18000)
USGS Quad: MCNEIL ISLAND Longitude: 122° 40.5' W (-122.67500)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 6705 I 1996
DESIGNATION: 944 6705 I
MONUMENTATION: Tidal Station disk VM#: 13569
AGENCY: National Ocean Service (NOS) IDB PID#:
SETTING CLASSIFICATION: Concrete loading ramp OPUS PID:
LATITUDE: 47° 10.8' N ( 47.18000) LONGITUDE: 122° 40.5' W (-122.67500)
The bench mark is a disk set in the concrete loading ramp of the Yoman Point
Ferry Terminal, on the east side of the foot passenger station, 32 m (104 ft)
WNW of the SE corner of the Ferry Terminal Building at the end of the terminal,
30 m (98 ft) NE of the inshore end of the loading ramp, and 0.61 m (2.0 ft) west
of the east edge of ramp.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 5 of 6
Station ID: 9446705 PUBLICATION DATE: 04/29/2004
Name: YOMAN POINT, ANDERSON ISLAND
WA
NOAA Chart: 18445 Latitude: 47° 10.8' N ( 47.18000)
USGS Quad: MCNEIL ISLAND Longitude: 122° 40.5' W (-122.67500)
T I D A L D A T U M S
Tidal datums at YOMAN POINT, ANDERSON ISLAND based on:
LENGTH OF SERIES: 7 MONTHS
TIME PERIOD: April 1996 - October 1996
TIDAL EPOCH: 1983-2001
CONTROL TIDE STATION: 9447130 SEATTLE, PUGET SOUND
Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in METERS:
MEAN HIGHER HIGH WATER MHHW = 4.108
MEAN HIGH WATER MHW = 3.826
MEAN TIDE LEVEL MTL = 2.362
MEAN SEA LEVEL MSL = 2.351
MEAN LOW WATER MLW = 0.897
MEAN LOWER LOW WATER MLLW = 0.000
North American Vertical Datum (NAVD88)
Bench Mark Elevation Information In METERS above:
Stamping or Designation MLLW MHW
6705 E 1978 7.383 3.557
6705 D 1978 6.116 2.290
6705 F 1984 9.167 5.341
6705 G 1984 9.165 5.339
6705 H 1996 7.188 3.362
6705 I 1996 8.020 4.194
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 6 of 6
Station ID: 9446705 PUBLICATION DATE: 04/29/2004
Name: YOMAN POINT, ANDERSON ISLAND
WA
NOAA Chart: 18445 Latitude: 47° 10.8' N ( 47.18000)
USGS Quad: MCNEIL ISLAND Longitude: 122° 40.5' W (-122.67500)
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.