U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Datums Page Page 1 of 6
Station ID: 9449771 PUBLICATION DATE: 06/15/2016
Name: ROSARIO, ORCAS ISLAND
WA
NOAA Chart: 18430 Latitude: 48° 38.8' N ( 48.64670)
USGS Quad: MOUNT CONSTITUTION Longitude: 122° 52.2' W (-122.87000)
To reach the tidal bench marks, proceed to the Rosario Resort Hotel property on
Cascade Bay. The tide staff and gage were located on the pier east of the First
Mate Cafe and north of the rip rap jetty.
T I D A L B E N C H M A R K S
PRIMARY BENCH MARK STAMPING: 9771 A 2015
DESIGNATION: 944 9771 A
MONUMENTATION: Tidal Station disk VM#: 21790
AGENCY: National Ocean Service IDB PID#:
SETTING CLASSIFICATION: rock outcrop OPUS PID#: BBDY48
LATITUDE: 48° 38.7' N ( 48.64572) LONGITUDE: 122° 52.3' W (-122.87183)
The bench mark is a disk set in a bedrock outcrop SW of the Rosario resort
marina above a gravel parking area, 17.78 m (58.3 ft) NE of the nearest pillar
of the white circular guest house number 1320, 15.62 m (51.2 ft) ENE of a large
cedar tree, 9.19 m (30.2 ft) WSW of the lone cedar tree above rock face along
the waterfront, 3.15 m (10.3 ft) WNW of the nearest edge of the sidewalk, and
1.90 m (6.2 ft) SE of the edge of the rock bluff above the parking area.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 2 of 6
Station ID: 9449771 PUBLICATION DATE: 06/15/2016
Name: ROSARIO, ORCAS ISLAND
WA
NOAA Chart: 18430 Latitude: 48° 38.8' N ( 48.64670)
USGS Quad: MOUNT CONSTITUTION Longitude: 122° 52.2' W (-122.87000)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 1 1935
DESIGNATION: 944 9771 TIDAL 1
MONUMENTATION: Tidal Station disk VM#: 14395
AGENCY: US Coast and Geodetic Survey
(USC&GS) IDB PID#:
SETTING CLASSIFICATION: Concrete foundation OPUS PID:
LATITUDE: 48° 38.8' N ( 48.64731) LONGITUDE: 122° 52.2' W (-122.87069)
The bench mark is a disk set in a concrete foundation of a large white building
motel called Boatel at the Rosario Resort, 18.29 m (60.0 ft) inshore from a
large privately owned pier and 0.15 m (0.5 ft) east of the SW corner of the
building.
BENCH MARK STAMPING: 3 1935
DESIGNATION: 944 9771 TIDAL 3
MONUMENTATION: Tidal Station disk VM#: 14397
AGENCY: US Coast and Geodetic Survey
(USC&GS) IDB PID#:
SETTING CLASSIFICATION: Concrete foundation OPUS PID:
LATITUDE: 48° 38.9' N ( 48.64767) LONGITUDE: 122° 52.3' W (-122.87089)
The bench mark is a disk set flush with the sidewalk in a concrete foundation of
a generator house, 58 m (190 ft) NW of the Rosario Resort pier with gas pumps
and 0.3 m (1 ft) east of the SW corner on the south side of the building.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 3 of 6
Station ID: 9449771 PUBLICATION DATE: 06/15/2016
Name: ROSARIO, ORCAS ISLAND
WA
NOAA Chart: 18430 Latitude: 48° 38.8' N ( 48.64670)
USGS Quad: MOUNT CONSTITUTION Longitude: 122° 52.2' W (-122.87000)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 4 1935
DESIGNATION: 944 9771 TIDAL 4
MONUMENTATION: Tidal Station disk VM#: 14398
AGENCY: US Coast and Geodetic Survey
(USC&GS) IDB PID#:
SETTING CLASSIFICATION: Rock outcrop OPUS PID:
LATITUDE: 48° 38.7' N ( 48.64569) LONGITUDE: 122° 52.4' W (-122.87286)
The bench mark is a disk set in the top of a rock outcrop, the highest point of
knoll back of a small promontory jutting from the west shore of Rosario Harbor,
247 m (810 ft) along the cement walk from the pier toward Rosario Resorts main
lodge, 201.17 m (660.0 ft) SW of Rosario Resort pier with gas pumps and 15.24 m
(50.0 ft) south of the sidewalk.
BENCH MARK STAMPING: BM 7 1973
DESIGNATION: 944 9771 TIDAL 7
MONUMENTATION: Tidal Station disk VM#: 14400
AGENCY: National Ocean Survey (NOS) IDB PID#:
SETTING CLASSIFICATION: Concrete sidewalk OPUS PID:
LATITUDE: 48° 38.8' N ( 48.64703) LONGITUDE: 122° 52.3' W (-122.87150)
The bench mark is a disk set horizontally in a concrete sidewalk on the north
side of the boat basin, south of a ship's figurehead at break in handrail,
112.78 m (370.0 ft) NE of bench mark 6 1973, 1.52 m (5.0 ft) north of a concrete
block stamped 1951, 0.21 m (0.7 ft) from a rail post and 0.09 m (0.3 ft) from
the edge of the sidewalk.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 4 of 6
Station ID: 9449771 PUBLICATION DATE: 06/15/2016
Name: ROSARIO, ORCAS ISLAND
WA
NOAA Chart: 18430 Latitude: 48° 38.8' N ( 48.64670)
USGS Quad: MOUNT CONSTITUTION Longitude: 122° 52.2' W (-122.87000)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: MC 1935 T37N R1W T36N R1W
DESIGNATION: MC 1935 T37N R1W T36N R1W
MONUMENTATION: Boundry marker VM#: 21791
AGENCY: IDB PID#:
SETTING CLASSIFICATION: OPUS PID:
LATITUDE: 48° 38.7' N ( 48.64511) LONGITUDE: 122° 52.3' W (-122.87236)
The bench mark is a disk without an agency logo on a concrete pedestal, 11.28 m
(37.0 ft) (slope distance) ESE of a stone wall, 10.13 m (33.2 ft) S of the SE
corner support for the stairs at the SE corner of 1300 Skagit building, 7.40 m
(24.3 ft) E of the gravel path, 4.05 m (13.3 ft) NE of the pine tree leaning at
a 45 degree angle, 2.00 m (6.6 ft) NW of the edge of the vegetation above the
rock shoreline and set in the top of a 13-cm square concrete post that is 0.44 m
(1.4 ft) tall.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 5 of 6
Station ID: 9449771 PUBLICATION DATE: 06/15/2016
Name: ROSARIO, ORCAS ISLAND
WA
NOAA Chart: 18430 Latitude: 48° 38.8' N ( 48.64670)
USGS Quad: MOUNT CONSTITUTION Longitude: 122° 52.2' W (-122.87000)
T I D A L D A T U M S
Tidal datums at ROSARIO, ORCAS ISLAND based on:
LENGTH OF SERIES: 3 MONTHS
TIME PERIOD: August 2015 - October 2015
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 = 2.404
MEAN HIGH WATER MHW = 2.208
MEAN TIDE LEVEL MTL = 1.455
MEAN SEA LEVEL MSL = 1.416
MEAN LOW WATER MLW = 0.703
MEAN LOWER LOW WATER MLLW = 0.000
North American Vertical Datum (NAVD88)
Bench Mark Elevation Information In METERS above:
Stamping or Designation MLLW MHW
9771 A 2015 9.311 7.103
1 1935 3.912 1.704
3 1935 4.480 2.272
4 1935 13.188 10.980
BM 7 1973 3.890 1.682
MC 1935 T37N R1W T36N R1W 6.441 4.233
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 6 of 6
Station ID: 9449771 PUBLICATION DATE: 06/15/2016
Name: ROSARIO, ORCAS ISLAND
WA
NOAA Chart: 18430 Latitude: 48° 38.8' N ( 48.64670)
USGS Quad: MOUNT CONSTITUTION Longitude: 122° 52.2' W (-122.87000)
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.