U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Datums Page Page 1 of 6
Station ID: 9410032 PUBLICATION DATE: 08/01/2018
Name: WILSON COVE, SAN CLEMENTE IS.
CA
NOAA Chart: 18763 Latitude: 33° 0.3' N ( 33.00500)
USGS Quad: SAN CLEMENTE ISLAND NORTH Longitude: 118° 33.4' W (-118.55700)
To reach the tide station from the Naval Auxiliary Landing Field (NALF) San
Clemente Island, proceed 3.7 km (2.3 mi) south on the main road from the air
terminal parking lot to a 3 way intersection with Wilson Cove North Road, turn
left on Wilson Cove North Road and proceed 2.0 km (1.2 mi) east and then north
and then west to the concrete pier and barge landing area. The tide station is
located on the concrete pier and the bench marks are along the shore.
T I D A L B E N C H M A R K S
PRIMARY BENCH MARK STAMPING: TIDAL 6 1971
DESIGNATION: 941 0032 TIDAL 6
MONUMENTATION: Tidal Station disk VM#: 22606
AGENCY: US Coast and Geodetic Survey IDB PID#:
SETTING CLASSIFICATION: Concrete Seawall OPUS PID#: BBFX11
LATITUDE: 33° 0.3' N ( 33.00483) LONGITUDE: 118° 33.4' W (-118.55744)
The primary bench mark is a USCGS disk set in the top of a 1.2 m (3.9 ft) wide
concrete seawall on the east side of the concrete pier, 16.56 m (54.3 ft) north
of power pole d2-4-1, 15.07 m (49.4 ft) WNW of the NW corner of building 60177,
7.51 m (24.6 ft) south of the light pole closest to land on the east side of the
pier, 5.62 m (18.4 ft) ESE of the east edge of the concrete vehicle ramp down to
the pier, 2.20 m (7.2 ft) south of the east side of the metal stairs to the
beach, and 0.50 m (1.6 ft) SSW of the seaward edge of the seawall.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 2 of 6
Station ID: 9410032 PUBLICATION DATE: 08/01/2018
Name: WILSON COVE, SAN CLEMENTE IS.
CA
NOAA Chart: 18763 Latitude: 33° 0.3' N ( 33.00500)
USGS Quad: SAN CLEMENTE ISLAND NORTH Longitude: 118° 33.4' W (-118.55700)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: NO 3 1933
DESIGNATION: TIDAL 3
MONUMENTATION: Tidal Station disk VM#: 22607
AGENCY: US Coast and Geodetic Survey IDB PID#:
SETTING CLASSIFICATION: Rock outcrop OPUS PID#: DY2122
LATITUDE: 33° 0.3' N ( 33.00511) LONGITUDE: 118° 33.3' W (-118.55550)
The bench mark is a USCGS bench mark set in bedrock outcrop along the shore of
Wilson Cove, 188 m (616.8 ft) east of the base of the concrete pier, 165 m
(541.3 ft) east of the side of the concrete pier, 57.5 m (188.6 ft) NNE of
building 60178, 4.60 m (15.1 ft) SSE of the seaward edge of the rock, 3.30 m
(10.8 ft) WNW of the edge of low scrub vegetation and about 0.02 m (0.1 ft)
higher than the rock.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 3 of 6
Station ID: 9410032 PUBLICATION DATE: 08/01/2018
Name: WILSON COVE, SAN CLEMENTE IS.
CA
NOAA Chart: 18763 Latitude: 33° 0.3' N ( 33.00500)
USGS Quad: SAN CLEMENTE ISLAND NORTH Longitude: 118° 33.4' W (-118.55700)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 4 1936
DESIGNATION: TIDAL 4
MONUMENTATION: Tidal Station disk VM#: 22608
AGENCY: US Coast and Geodetic Survey IDB PID#:
SETTING CLASSIFICATION: Rock outcrop OPUS PID#: DY2123
LATITUDE: 33° 0.3' N ( 33.00519) LONGITUDE: 118° 33.3' W (-118.55525)
The bench mark is a USCGS bench mark disk set in a bedrock outcrop ledge along
the shoreline of Wilson Cove, 212 m (695.5 ft) east of the base of the pier, 184
m (603.7 ft) east of the NE corner of the pier, 4.55 m (14.9 ft) ESE of the
seaward edge of the rock outcrop, 2.90 m (9.5 ft) north of the edge of low scrub
vegetation, 1.10 m (3.6 ft) WSW of the NE side of the rock ledge where it drops
off to a rock gully and about 0.02 m (0.1 ft) higher than the rock.
BENCH MARK STAMPING: 0032 A 2018
DESIGNATION: 941 0032 A
MONUMENTATION: Bench Mark disk VM#: 22609
AGENCY: National Ocean Service IDB PID#:
SETTING CLASSIFICATION: Concrete building foundation OPUS PID:
LATITUDE: 33° 0.3' N ( 33.00450) LONGITUDE: 118° 33.4' W (-118.55642)
The bench mark is a disk set in the SE corner of the concrete foundation of
building 60138 in the Wilson Cove port area, 27.53 m (90.3 ft) WSW of the SW
corner of building 60178, 19.57 m (64.2 ft) NW of the vertical white pipe on the
south side of the road, 10.24 m (33.6 ft) north of the centerline of the road,
3.70 m (12.1 ft) NE of the NE corner of a rectangular storm drain, 1.83 m (6.0
ft) WNW of the NW corner of the bottom of 3 concrete steps down from the road
level towards the building, and 1.51 m (5.0 ft) east of the east edge of a man
door on the south side of building 60138.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 4 of 6
Station ID: 9410032 PUBLICATION DATE: 08/01/2018
Name: WILSON COVE, SAN CLEMENTE IS.
CA
NOAA Chart: 18763 Latitude: 33° 0.3' N ( 33.00500)
USGS Quad: SAN CLEMENTE ISLAND NORTH Longitude: 118° 33.4' W (-118.55700)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 0032 B 2018
DESIGNATION: 941 0032 B
MONUMENTATION: Bench Mark disk VM#: 22610
AGENCY: National Ocean Service IDB PID#:
SETTING CLASSIFICATION: Concrete base for large bollard OPUS PID#: BBFX10
LATITUDE: 33° 0.3' N ( 33.00517) LONGITUDE: 118° 33.5' W (-118.55806)
The bench mark is a disk set in the circular concrete base of a 1.07 m (3.5 ft)
high by 0.65 m (2.1 ft) wide steel bollard with square base, 26.39 m (86.6 ft)
NW of a flagpole along the north side of the road, 14.37 m (47.1 ft) east of the
second large steel bollard, 6.35 m (20.8 ft) north of the NE corner of a
concrete catch basin for a fuel line box, 5.22 m (17.1 ft) SSW of the large
concrete post along the east side of the barge landing, 1.72 m (5.6 ft) east of
a 30 degree bend in a 0.17 m (0.6 ft) diameter white elevated fuel pipe, 0.64 m
(2.1 ft) south of the center of the bollard, 0.14 m (0.5 ft) south of the edge
of the square base and about 0.11 m (0.4 ft) higher than the surrounding
concrete.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 5 of 6
Station ID: 9410032 PUBLICATION DATE: 08/01/2018
Name: WILSON COVE, SAN CLEMENTE IS.
CA
NOAA Chart: 18763 Latitude: 33° 0.3' N ( 33.00500)
USGS Quad: SAN CLEMENTE ISLAND NORTH Longitude: 118° 33.4' W (-118.55700)
T I D A L D A T U M S
Tidal datums at WILSON COVE, SAN CLEMENTE IS. based on:
LENGTH OF SERIES: 3 MONTHS
TIME PERIOD: March 2018 - May 2018
TIDAL EPOCH: 1983-2001
CONTROL TIDE STATION: 9410230 LA JOLLA, PACIFIC OCEAN
Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in METERS:
MEAN HIGHER HIGH WATER MHHW = 1.598
MEAN HIGH WATER MHW = 1.369
MEAN TIDE LEVEL MTL = 0.821
MEAN SEA LEVEL MSL = 0.814
MEAN LOW WATER MLW = 0.272
North American Vertical Datum NAVD88 = 0.000
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 6 1971 5.319 3.950
NO 3 1933 4.465 3.096
4 1936 5.444 4.075
0032 A 2018 6.205 4.836
0032 B 2018 3.778 2.409
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 6 of 6
Station ID: 9410032 PUBLICATION DATE: 08/01/2018
Name: WILSON COVE, SAN CLEMENTE IS.
CA
NOAA Chart: 18763 Latitude: 33° 0.3' N ( 33.00500)
USGS Quad: SAN CLEMENTE ISLAND NORTH Longitude: 118° 33.4' W (-118.55700)
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.