U.S. DEPARTMENT OF COMMERCE
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National Ocean Service
Datums Page Page 1 of 7
Station ID: 9414131 PUBLICATION DATE: 05/07/2014
Name: PILLAR POINT HARBOR
CA
NOAA Chart: 18680 Latitude: 37° 30.1' N ( 37.50250)
USGS Quad: MONTARA MOUNTAIN, CA Longitude: 122° 28.9' W (-122.48217)
To reach the tide station from the intersection of US Highway 1 and Capistrano
Road in Half Moon Bay, CA, proceed SW on Capistrano Road for 125.8 m (413 ft),
then take the first left and go 77.1 m (253 ft), then take the next right and go
118.9 m (390 ft), and arrive at Johnson Pier. Tide station is located 85.64 m
(280.97 ft) S from the N end of the pier, 89.76 m (294.48 ft) N of the SE corner
of pier, 5.86 m (19.23 ft) N of NE corner of E dock gangway, and 1.84 m (6.04
ft) N of light pole.
T I D A L B E N C H M A R K S
PRIMARY BENCH MARK STAMPING: HBR 2 USGS
DESIGNATION: HBR 2
MONUMENTATION: Tidal Station disk VM#: 21006
AGENCY: US Geological Survey IDB PID#:
SETTING CLASSIFICATION: Concrete Curb OPUS PID:
LATITUDE: 37° 30.2' N ( 37.50297) LONGITUDE: 122° 29.0' W (-122.48278)
The primary benchmark is a 1 disk set in a concrete curb 63.55 m (204.5 ft) W
from the NW corner of Johnson pier, 13.26 m (43.5 ft) E of the base of crane,
0.3 m (1 ft) N of rail, and 3.29 m (10.8 ft) S of edge of parking lot.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 2 of 7
Station ID: 9414131 PUBLICATION DATE: 05/07/2014
Name: PILLAR POINT HARBOR
CA
NOAA Chart: 18680 Latitude: 37° 30.1' N ( 37.50250)
USGS Quad: MONTARA MOUNTAIN, CA Longitude: 122° 28.9' W (-122.48217)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 4131 A
DESIGNATION: 941 4131 A PIER
MONUMENTATION: Tidal Station disk VM#: 21007
AGENCY: US Army Corps of Engineers IDB PID#:
SETTING CLASSIFICATION: Concrete curb OPUS PID:
LATITUDE: 37° 30.2' N ( 37.50286) LONGITUDE: 122° 28.9' W (-122.48206)
The benchmark is a 4 disk set in a concrete walkway W of Johnson Pier 13.26 m
(43.5 ft) S of flag pole, 6.19 m (20.3 ft) E of eastern leg of bench, 0.46 m
(1.5 ft) of stop sign, and 0.33 m (1.08 ft) N of rail.
BENCH MARK STAMPING: TIDAL 5
DESIGNATION: 941 4131 TIDAL 5
MONUMENTATION: Tidal Station disk VM#: 21008
AGENCY: National Geodetic Survey IDB PID#: HT0455
SETTING CLASSIFICATION: Concrete pipe culvert OPUS PID:
LATITUDE: 37° 30.2' N ( 37.50369) LONGITUDE: 122° 29.1' W (-122.48547)
From the intersection of US Highway 1 and Capistrano Road, proceed SW on
Capistrano Road for 0.4 km (0.25 mi) to concrete retaining wall. The benchmark
is a 3.5 disk set inside a concrete pipe culvert 23.3 m (76.4 ft) SE of the N
end of rail, 7.0 m (23.0 ft) NW of light pole, 5.7 m (18.7 ft) SW of centerline
of road, 0.12 m (0.4 ft) NE of rail, and 0.37 m (1.2 ft) below ground.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 3 of 7
Station ID: 9414131 PUBLICATION DATE: 05/07/2014
Name: PILLAR POINT HARBOR
CA
NOAA Chart: 18680 Latitude: 37° 30.1' N ( 37.50250)
USGS Quad: MONTARA MOUNTAIN, CA Longitude: 122° 28.9' W (-122.48217)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 4131 B
DESIGNATION: 941 4131 B Ramp
MONUMENTATION: Tidal Station disk VM#: 21009
AGENCY: US Army Corps of Engineers IDB PID#:
SETTING CLASSIFICATION: Concrete curb OPUS PID:
LATITUDE: 37° 30.2' N ( 37.50256) LONGITUDE: 122° 28.6' W (-122.47722)
The benchmark is located near the Pillar Point Harbor boat launch ramp. The
benchmark is a 4 disk set in a concrete sidewalk 9.5 m (31.2 ft) SE of the SW
corner of restroom, 5.91 m (19.4 ft) SSW of the SE corner of restroom, 7.52 m
(24.7 ft) E of curb, and 1.19 m (3.9 ft) W of SW corner of cleaning stall.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 4 of 7
Station ID: 9414131 PUBLICATION DATE: 05/07/2014
Name: PILLAR POINT HARBOR
CA
NOAA Chart: 18680 Latitude: 37° 30.1' N ( 37.50250)
USGS Quad: MONTARA MOUNTAIN, CA Longitude: 122° 28.9' W (-122.48217)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: HMB 25
DESIGNATION: HMB 25 USACE
MONUMENTATION: Tidal Station disk VM#: 21010
AGENCY: US Army Corps of Engineers IDB PID#:
SETTING CLASSIFICATION: Concrete curb OPUS PID:
LATITUDE: 37° 30.1' N ( 37.50231) LONGITUDE: 122° 28.5' W (-122.47547)
The benchmark is located in the SE end of Sam s Chowder House parking lot at
4210 N Cabrillo Hwy in Half Moon Bay, CA. The benchmark is a 2 disk set in a
concrete walkway 22.1 m (72.5 ft) SE of the SE corner of restaurant, 10.5 m
(34.6 ft) W of western side of metal gate, 2.10 m (6.9 ft) S of light pole, and
1.98 m (6.5 ft) W of the E side of rail.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 5 of 7
Station ID: 9414131 PUBLICATION DATE: 05/07/2014
Name: PILLAR POINT HARBOR
CA
NOAA Chart: 18680 Latitude: 37° 30.1' N ( 37.50250)
USGS Quad: MONTARA MOUNTAIN, CA Longitude: 122° 28.9' W (-122.48217)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: N1240
DESIGNATION: N1240 1972
MONUMENTATION: Tidal Station disk VM#: 21011
AGENCY: National Geodetic Survey IDB PID#: HT0453
SETTING CLASSIFICATION: Concrete conduit OPUS PID:
LATITUDE: 37° 30.1' N ( 37.50108) LONGITUDE: 122° 28.2' W (-122.47056)
From the intersection of US Highway 1 and Coronado St. in Half Moon Bay, proceed
NW on US Highway 1 for 0.3 km (0.2 mi). Benchmark is a 3.5 disk located N of
the highway and set into the top of a concrete head wall of double pipe culverts
32.89 m (107.9 ft) NW of E end of guard rail, 16.64 m (54.6 ft) SE of W end of
guard rail, 10.52 m (34.5 ft) NE of centerline of highway, and 0.40 m (1.3 ft)
NW of the SW end of head wall.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 6 of 7
Station ID: 9414131 PUBLICATION DATE: 05/07/2014
Name: PILLAR POINT HARBOR
CA
NOAA Chart: 18680 Latitude: 37° 30.1' N ( 37.50250)
USGS Quad: MONTARA MOUNTAIN, CA Longitude: 122° 28.9' W (-122.48217)
T I D A L D A T U M S
Tidal datums at PILLAR POINT HARBOR based on:
LENGTH OF SERIES: 3 MONTHS
TIME PERIOD: June 2011 - August 2011
TIDAL EPOCH: 1983-2001
CONTROL TIDE STATION: 9415020 POINT REYES, DRAKES BAY
Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in METERS:
MEAN HIGHER HIGH WATER MHHW = 1.707
MEAN HIGH WATER MHW = 1.509
MEAN TIDE LEVEL MTL = 0.923
MEAN SEA LEVEL MSL = 0.911
MEAN LOW WATER MLW = 0.338
MEAN LOWER LOW WATER MLLW = 0.000
North American Vertical Datum NAVD88 = -0.013
North American Vertical Datum (NAVD88)
Bench Mark Elevation Information In METERS above:
Stamping or Designation MLLW MHW
HBR 2 USGS 3.804 2.295
4131 A 3.810 2.301
TIDAL 5 4.322 2.813
4131 B 4.430 2.921
HMB 25 9.921 8.412
N1240 6.076 4.567
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 7 of 7
Station ID: 9414131 PUBLICATION DATE: 05/07/2014
Name: PILLAR POINT HARBOR
CA
NOAA Chart: 18680 Latitude: 37° 30.1' N ( 37.50250)
USGS Quad: MONTARA MOUNTAIN, CA Longitude: 122° 28.9' W (-122.48217)
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.