U.S. DEPARTMENT OF COMMERCE
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National Ocean Service
Datums Page Page 1 of 5
Station ID: 9448657 PUBLICATION DATE: 09/18/2015
Name: TURNER BAY, SIMILK BAY
WA
NOAA Chart: 18427 Latitude: 48° 26.7' N ( 48.44500)
USGS Quad: CRESCENT HARBOR Longitude: 122° 33.3' W (-122.55500)
To reach the tidal bench marks from Anacortes, drive east out of town on Highway
20, turn right on Reservation Road, turn right on second paved road and then
left on unpaved private road to dock. You will need permission of the landowner
to open the gate across the private drive. The tidal bench marks are located
along the road on the west side of the jetty owned by Culbertson Marine
Construction Company.
T I D A L B E N C H M A R K S
PRIMARY BENCH MARK STAMPING: SITC NAVD 88
DESIGNATION: 944 8657 SITC NAVD
MONUMENTATION: Bench Mark disk VM#: 16175
AGENCY: Swinomish Indian Tribal Community (SITC)IDB PID#:
SETTING CLASSIFICATION: Concrete pavement OPUS PID:
LATITUDE: 48° 26.7' N ( 48.44500) LONGITUDE: 122° 33.3' W (-122.55500)
The primary bench mark is a disk set in concrete pavement located on western end
of spit on the east side of the waterways that runs along Jetty owned by
Culbertson Marine Construction at Turner Bay, 165 m (541 ft) east of center
road, and 10m (33 ft) east of west end of spit.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 2 of 5
Station ID: 9448657 PUBLICATION DATE: 09/18/2015
Name: TURNER BAY, SIMILK BAY
WA
NOAA Chart: 18427 Latitude: 48° 26.7' N ( 48.44500)
USGS Quad: CRESCENT HARBOR Longitude: 122° 33.3' W (-122.55500)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 8657 A 2000
DESIGNATION: 944 8657 A
MONUMENTATION: Tidal Station disk VM#: 16176
AGENCY: National Ocean Service (NOS) IDB PID#:
SETTING CLASSIFICATION: Concrete foundation OPUS PID:
LATITUDE: 48° 26.7' N ( 48.44500) LONGITUDE: 122° 33.3' W (-122.55500)
The bench mark is a disk set in concrete foundation for a boat skid at the end
of a jetty owned by Culbertson Marine Construction in Turner Bay, 6.92 m (22.7
ft) west of east side of skid, 1.16 m (3.8 ft) below the highest part of the
skid on east side, 0.15 m (0.5 ft) north of south edge of the foundation, and
0.12 m (0.4 ft) east of west edge of foundation.
BENCH MARK STAMPING: 8657 B 2000
DESIGNATION: 944 8657 B
MONUMENTATION: Tidal Station disk VM#: 16177
AGENCY: National Ocean Service (NOS) IDB PID#:
SETTING CLASSIFICATION: Bedrock OPUS PID:
LATITUDE: 48° 26.7' N ( 48.44500) LONGITUDE: 122° 33.3' W (-122.55500)
The bench mark is a disk set in bedrock below a Madrona tree with a witness sign
in a small cove near west side of a jetty owned by Culbertson Marine
Construction in Turner Bay, 30 m (98 ft) west of middle of a road on jetty, 10 m
(33 ft) west of west side of jetty, and 4.14 m (13.6 ft) south of a large fire
tree with a wire rope around trunk.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 3 of 5
Station ID: 9448657 PUBLICATION DATE: 09/18/2015
Name: TURNER BAY, SIMILK BAY
WA
NOAA Chart: 18427 Latitude: 48° 26.7' N ( 48.44500)
USGS Quad: CRESCENT HARBOR Longitude: 122° 33.3' W (-122.55500)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 8657 C 2000
DESIGNATION: 944 8657 C
MONUMENTATION: Tidal Station disk VM#: 16178
AGENCY: National Ocean Service (NOS) IDB PID#:
SETTING CLASSIFICATION: Bedrock OPUS PID:
LATITUDE: 48° 26.7' N ( 48.44500) LONGITUDE: 122° 33.3' W (-122.55500)
The bench mark is a disk set on west side of a road leading to a jetty owned by
Culbertson Marine Construction on Turner Bay, 19.8 m (65.0 ft) north of northern
most corner of a welding shop, 6.10 m (20.0 ft) west of middle of a road on
jetty, and 0.91 m (3.0 ft) above grade.
BENCH MARK STAMPING: 8657 D 2000
DESIGNATION: 944 8657 D
MONUMENTATION: Tidal Station disk VM#: 16179
AGENCY: National Ocean Service (NOS) IDB PID#:
SETTING CLASSIFICATION: Bedrock OPUS PID:
LATITUDE: 48° 26.7' N ( 48.44500) LONGITUDE: 122° 33.3' W (-122.55500)
The bench mark is a disk set on a road leading to a jetty owned by Culbertson
Marine Construction on Turner Bay, 137 m (450 ft) west of northern point of a
small island in channel, 100 m (328 ft) north of north end of pond on west side
of road, 6.55 m (21.5 ft) west of center of road, 2.25 m (7.4 ft) north of an
orange NOS witness post, and 0.91 m (3.0 ft) above grade.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 4 of 5
Station ID: 9448657 PUBLICATION DATE: 09/18/2015
Name: TURNER BAY, SIMILK BAY
WA
NOAA Chart: 18427 Latitude: 48° 26.7' N ( 48.44500)
USGS Quad: CRESCENT HARBOR Longitude: 122° 33.3' W (-122.55500)
T I D A L D A T U M S
Tidal datums at TURNER BAY, SIMILK BAY based on:
LENGTH OF SERIES: 2 MONTHS
TIME PERIOD: June 2000 - July 2000
TIDAL EPOCH: 1983-2001
CONTROL TIDE STATION: 9449880 FRIDAY HARBOR, SAN JUAN CHANNEL
Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in METERS:
MEAN HIGHER HIGH WATER MHHW = 3.152
MEAN HIGH WATER MHW = 2.888
MEAN TIDE LEVEL MTL = 1.825
MEAN SEA LEVEL MSL = 1.812
MEAN LOW WATER MLW = 0.761
MEAN LOWER LOW WATER MLLW = 0.000
North American Vertical Datum (NAVD88)
Bench Mark Elevation Information In METERS above:
Stamping or Designation MLLW MHW
SITC NAVD 88 3.848 0.960
8657 A 2000 4.289 1.401
8657 B 2000 4.639 1.751
8657 C 2000 5.574 2.686
8657 D 2000 6.263 3.375
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 5 of 5
Station ID: 9448657 PUBLICATION DATE: 09/18/2015
Name: TURNER BAY, SIMILK BAY
WA
NOAA Chart: 18427 Latitude: 48° 26.7' N ( 48.44500)
USGS Quad: CRESCENT HARBOR Longitude: 122° 33.3' W (-122.55500)
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.