U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Datums Page Page 1 of 6
Station ID: 9412553 PUBLICATION DATE: 11/13/2003
Name: SAN SIMEON
CA
NOAA Chart: 18700 Latitude: 35° 38.5' N ( 35.64170)
USGS Quad: SAN SIMEON Longitude: 121° 11.3' W (-121.18800)
To reach the tidal bench marks take US Highway 1 to the William Randolph Hearst
State Beach Exit, and proceed south (seaward) into the parking area. The bench
marks are located in a around the parking area, and extend 0.80 km (0.5 mi)
south along Old Highway 1 to a group of 5 warehouses. The tide gage and staff
were located on the southwest end of the pier. The former site (1933-34) was
located on a pier 365 m (1200 ft) west of the existing pier.
T I D A L B E N C H M A R K S
PRIMARY BENCH MARK STAMPING: NO 1 1933
DESIGNATION: 941 2553 TIDAL 1
MONUMENTATION: Tidal Station disk VM#: 8045
AGENCY: US Coast and Geodetic Survey
(USC&GS) IDB PID#: FV1124
SETTING CLASSIFICATION: Step OPUS PID:
LATITUDE: 35° 38.6' N ( 35.64330) LONGITUDE: 121° 11.5' W (-121.19200)
The primary bench mark is a disk set flush in the fifth step from top of the
western stairs on the south side of a Stucco Warehouse with a tiled roof, 56.7 m
(186 ft) south of the centerline of Old Highway 1, 18.6 m (61 ft) west of bench
mark BM 4 1934, 0.94 m (3.1 ft) south of the SW corner of the easternmost of
five warehouses.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 2 of 6
Station ID: 9412553 PUBLICATION DATE: 11/13/2003
Name: SAN SIMEON
CA
NOAA Chart: 18700 Latitude: 35° 38.5' N ( 35.64170)
USGS Quad: SAN SIMEON Longitude: 121° 11.3' W (-121.18800)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: NO 2 1933
DESIGNATION: 941 2553 TIDAL 2
MONUMENTATION: Tidal Station disk VM#: 8046
AGENCY: US Coast and Geodetic Survey
(USC&GS) IDB PID#: FV1125
SETTING CLASSIFICATION: Concrete apron OPUS PID:
LATITUDE: 35° 38.6' N ( 35.64330) LONGITUDE: 121° 11.6' W (-121.19300)
The bench mark is a disk set flush in the south end of concrete apron on the
west side of the southernmost corrugated iron warehouse, 57.9 m (190 ft) south
of the westerly extended centerline of Old Highway 1, 10.0 m (33.0 ft) south of
north corner of warehouse, 5.33 m (17.5 ft) north of SW corner of warehouse,
0.24 m (0.8 ft) west of west edge of corrugated warehouse.
BENCH MARK STAMPING: BM 4 1934
DESIGNATION: 941 2553 TIDAL 4
MONUMENTATION: Tidal Station disk VM#: 8047
AGENCY: US Coast and Geodetic Survey
(USC&GS) IDB PID#: FV1123
SETTING CLASSIFICATION: Pavement OPUS PID:
LATITUDE: 35° 38.6' N ( 35.64330) LONGITUDE: 121° 11.5' W (-121.19200)
The bench mark is a disk set flush in lowest step at SE corner of easternmost of
five warehouses, 59.1 m (194 ft) south of centerline of Old Highway 1, 1.0 m
(3.3 ft) south of SE corner of warehouse.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 3 of 6
Station ID: 9412553 PUBLICATION DATE: 11/13/2003
Name: SAN SIMEON
CA
NOAA Chart: 18700 Latitude: 35° 38.5' N ( 35.64170)
USGS Quad: SAN SIMEON Longitude: 121° 11.3' W (-121.18800)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 2553 A 1977
DESIGNATION: 941 2553 A TIDAL
MONUMENTATION: Tidal Station disk VM#: 8048
AGENCY: National Ocean Survey (NOS) IDB PID#: FV1121
SETTING CLASSIFICATION: Galvanized steel rod OPUS PID:
LATITUDE: 35° 38.6' N ( 35.64330) LONGITUDE: 121° 11.3' W (-121.18800)
The bench mark is a disk located in the William R. Hearst Memorial State Beach
Pinic area near the inshore end of the pier, 115.2 m (378 ft) SW of bench mark
2553 B 1977, 17.9 m (59.0 ft) NW of the end of the pier, 16.7 m (55.0 ft) WSW of
the westernmost corner of concrete block restroom, set in a grove of large
trees, 2.7 m (9.0 ft) NE of a 1.37 m (4.5 ft) diameter eucalyptus tree. The
bench mark is set 0.15 m (0.5 ft) below ground level, crimped to the top of a
galvanized steel rod driven 2.4 m (8 ft) to refusal and encased in a 4-inch PVC
pipe and concrete kickblock.
BENCH MARK STAMPING: 2553 B 1977
DESIGNATION: 941 2553 B TIDAL
MONUMENTATION: Tidal Station disk VM#: 8049
AGENCY: National Ocean Survey (NOS) IDB PID#: FV1119
SETTING CLASSIFICATION: Galvanized steel rod OPUS PID:
LATITUDE: 35° 38.6' N ( 35.64330) LONGITUDE: 121° 11.2' W (-121.18700)
The bench mark is a disk located along Old Highway 1, west of the entrance to
William R. Hearst Memorial State Beach, 15.8 m (52.0 ft) WNW of centerline of
the entrance road to the State Beach, 7.9 m (26.0 ft) SW of the centerline of
Old Highway 1, 0.5 m (1.8 ft) NNE of a wire mesh (hurricane) fence. The bench
mark is set 9 cm (0.3 ft) below ground level, crimped to the top of a galvanized
steel rod driven 3.3 m (11 ft) to refusal and encased in a 4-inch PVC pipe and
concrete kickblock.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 4 of 6
Station ID: 9412553 PUBLICATION DATE: 11/13/2003
Name: SAN SIMEON
CA
NOAA Chart: 18700 Latitude: 35° 38.5' N ( 35.64170)
USGS Quad: SAN SIMEON Longitude: 121° 11.3' W (-121.18800)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 2553 C 1977
DESIGNATION: 941 2553 C TIDAL
MONUMENTATION: Tidal Station disk VM#: 8050
AGENCY: National Ocean Survey (NOS) IDB PID#: FV1120
SETTING CLASSIFICATION: Galvanized steel rod OPUS PID:
LATITUDE: 35° 38.7' N ( 35.64500) LONGITUDE: 121° 11.2' W (-121.18700)
The bench mark is a disk located along the west side of US Highway 1, at the
fence junction with Old Highway 1 from San Simeon, 72.2 m (237 ft) NW of bench
mark 2553 B 1977, 17.7 m (58 ft) SSW of the centerline of US Highway 1, 9.7 m
(32 ft) NNE of the centerline of Old Highway 1, 0.8 m (2.5 ft) NNE of a wire
mesh (hurricane) fence. The bench mark is set 9 cm (0.3 ft) below ground level,
crimped to the top of a galvanized steel rod driven 1.5 m (5 ft) to refusal and
encased in a 4-inch PVC pipe and concrte kickblock.
BENCH MARK STAMPING: 19 1917
DESIGNATION: 19 USGS
MONUMENTATION: Survey disk VM#: 8051
AGENCY: USGS IDB PID#: FV0986
SETTING CLASSIFICATION: Abutment OPUS PID:
LATITUDE: 35° 38.6' N ( 35.64330) LONGITUDE: 121° 11.3' W (-121.18800)
The bench mark is a disk set flush in the top of the SE concrete guardrail of
the bridge over the Arroyo del Puerto at the east end of the town of the San
Simeon, 6.58 m (21.6 ft) NE of the SW end of the wall, 0.18 m (0.6 ft) SE of the
NW edge of the wall.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 5 of 6
Station ID: 9412553 PUBLICATION DATE: 11/13/2003
Name: SAN SIMEON
CA
NOAA Chart: 18700 Latitude: 35° 38.5' N ( 35.64170)
USGS Quad: SAN SIMEON Longitude: 121° 11.3' W (-121.18800)
T I D A L D A T U M S
Tidal datums at SAN SIMEON based on:
LENGTH OF SERIES: 3 MONTHS
TIME PERIOD: May 1978 - July 1978
TIDAL EPOCH: 1983-2001
CONTROL TIDE STATION: 9412110 PORT SAN LUIS, 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 = 1.381
MEAN TIDE LEVEL MTL = 0.851
MEAN SEA LEVEL MSL = 0.840
MEAN LOW WATER MLW = 0.322
MEAN LOWER LOW WATER MLLW = 0.000
North American Vertical Datum NAVD88 = -0.068
North American Vertical Datum (NAVD88)
Bench Mark Elevation Information In METERS above:
Stamping or Designation MLLW MHW
NO 1 1933 6.279 4.898
NO 2 1933 7.581 6.200
BM 4 1934 5.569 4.188
2553 A 1977 9.164 7.783
2553 B 1977 13.916 12.535
2553 C 1977 12.855 11.474
19 1917 6.783 5.402
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 6 of 6
Station ID: 9412553 PUBLICATION DATE: 11/13/2003
Name: SAN SIMEON
CA
NOAA Chart: 18700 Latitude: 35° 38.5' N ( 35.64170)
USGS Quad: SAN SIMEON Longitude: 121° 11.3' W (-121.18800)
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.