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Bench Mark Sheet for 9449828, HANBURY POINT, SAN JUAN ISLAND WA

Superseded Epoch

Large map location marker Station Location
Small red map location marker Published bench mark
Small blue map location marker Unpublished bench mark

Bench mark positions only appear on the map if their coordinates in the CO-OPS database are at the precision of degrees/minutes/seconds/and tenths of seconds. If the coordinates are less precise, the mark will not appear.

Printable version

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
Datums Page                                                        Page  1 of  5

                                                                                
Station ID: 9449828                         PUBLICATION DATE:  07/15/2004
Name:       HANBURY POINT, SAN JUAN ISLAND                    
            WA
NOAA Chart: 18433                           Latitude:   48° 34.9' N (  48.58170)
USGS Quad:  ROCHE HARBOR                    Longitude: 123° 10.2' W (-123.17000)


To reach the tidal bench marks from Roche Harbor on San Juan Island, proceed by
boat WSW for about 3.7 km (2.3 statute mi) via Mosquito Pass to Hanbury Point. 
The bench marks are located at Hanbury Point, south of a pier and along the
shore between the shoreline and a rock bluff.  The gage and staff were located
at the offshore end of the pier.


                         T I D A L   B E N C H   M A R K S


                 PRIMARY BENCH MARK STAMPING:  BM 1 1973
                         DESIGNATION:          944 9828 TIDAL 1

MONUMENTATION:           Tidal Station disk                    VM#:         9310
AGENCY:                  National Ocean Survey (NOS)           IDB PID#:        
SETTING CLASSIFICATION:  Bedrock outcrop                       OPUS PID:        
LATITUDE:   48° 34.7' N (  48.57830)          LONGITUDE: 123° 10.4' W (-123.17300)


The primary bench mark is a disk set in a bedrock ledge of the bluff, 8 m (26
ft) south of the pier and boat house, and about level with the floor of the
fixed pier.



                         BENCH MARK STAMPING:  BM 2 1973
                         DESIGNATION:          944 9828 TIDAL 2

MONUMENTATION:           Tidal Station disk                    VM#:         9311
AGENCY:                  National Ocean Survey (NOS)           IDB PID#:        
SETTING CLASSIFICATION:  Bedrock outcrop                       OPUS PID:        
LATITUDE:   48° 34.7' N (  48.57830)          LONGITUDE: 123° 10.4' W (-123.17300)


The bench mark is a disk set in a bedrock ledge of the bluff, 34 m (112 ft)
south of the pier, 26 m (86 ft) south of bench mark BM 1 1973, and 1 m (3 ft)
above the approximate high water line.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  2 of  5

                                                                                
Station ID: 9449828                         PUBLICATION DATE:  07/15/2004
Name:       HANBURY POINT, SAN JUAN ISLAND                    
            WA
NOAA Chart: 18433                           Latitude:   48° 34.9' N (  48.58170)
USGS Quad:  ROCHE HARBOR                    Longitude: 123° 10.2' W (-123.17000)


                         T I D A L   B E N C H   M A R K S


                         BENCH MARK STAMPING:  BM 3 1973
                         DESIGNATION:          944 9828 TIDAL 3

MONUMENTATION:           Tidal Station disk                    VM#:         9312
AGENCY:                  National Ocean Survey (NOS)           IDB PID#:        
SETTING CLASSIFICATION:  Bedrock outcrop                       OPUS PID:        
LATITUDE:   48° 34.7' N (  48.57830)          LONGITUDE: 123° 10.4' W (-123.17300)


The bench mark is a disk set in a bedrock ledge of the bluff, 74 m (242 ft)
south of the pier, 40 m (130 ft) south of bench mark BM 2 1973, and 1 m (3 ft)
above the approximate high water line.



                         BENCH MARK STAMPING:  BM 4 1973
                         DESIGNATION:          944 9828 TIDAL 4

MONUMENTATION:           Tidal Station disk                    VM#:         9313
AGENCY:                  National Ocean Survey (NOS)           IDB PID#:        
SETTING CLASSIFICATION:  Bedrock outcrop                       OPUS PID:        
LATITUDE:   48° 34.7' N (  48.57830)          LONGITUDE: 123° 10.4' W (-123.17300)


The bench mark is a disk set in a bedrock ledge of the bluff, 98 m (320 ft)
south of the pier, 24 m (78 ft) south of bench mark BM 3 1973, 3 m (9 ft) north
of the west corner of the bottom concrete step of the stairs leading up the
bluff, and 1 m (3 ft) above the approximate high water line.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  3 of  5

                                                                                
Station ID: 9449828                         PUBLICATION DATE:  07/15/2004
Name:       HANBURY POINT, SAN JUAN ISLAND                    
            WA
NOAA Chart: 18433                           Latitude:   48° 34.9' N (  48.58170)
USGS Quad:  ROCHE HARBOR                    Longitude: 123° 10.2' W (-123.17000)


                         T I D A L   B E N C H   M A R K S


                         BENCH MARK STAMPING:  BM 5 1973
                         DESIGNATION:          944 9828 TIDAL 5

MONUMENTATION:           Tidal Station disk                    VM#:         9314
AGENCY:                  National Ocean Survey (NOS)           IDB PID#:        
SETTING CLASSIFICATION:  Bedrock outcrop                       OPUS PID:        
LATITUDE:   48° 34.7' N (  48.57830)          LONGITUDE: 123° 10.4' W (-123.17300)


The bench mark is a disk set in a bedrock ledge of the bluff, 138 m (454 ft)
south of the pier, 41 m (134 ft) south of bench mark BM 4 1973, and 1 m (3 ft)
above the approximate high water line.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  4 of  5

                                                                                
Station ID: 9449828                         PUBLICATION DATE:  07/15/2004
Name:       HANBURY POINT, SAN JUAN ISLAND                    
            WA
NOAA Chart: 18433                           Latitude:   48° 34.9' N (  48.58170)
USGS Quad:  ROCHE HARBOR                    Longitude: 123° 10.2' W (-123.17000)


                            T I D A L   D A T U M S 


Tidal datums at HANBURY POINT, SAN JUAN ISLAND based on:

     LENGTH OF SERIES:      2 MONTHS
     TIME PERIOD:           September 1974 - October 1974
     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   =  2.325
     MEAN HIGH WATER                            MHW    =  2.123
     MEAN TIDE LEVEL                            MTL    =  1.416
     MEAN SEA LEVEL                             MSL    =  1.367
     MEAN LOW WATER                             MLW    =  0.709
     MEAN LOWER LOW WATER                       MLLW   =  0.000

North American Vertical Datum (NAVD88)

Bench Mark Elevation Information                In METERS above:

     Stamping or Designation                    MLLW        MHW

     BM 1 1973                                   3.921    1.798
     BM 2 1973                                   3.559    1.436
     BM 3 1973                                   3.505    1.382
     BM 4 1973                                   3.859    1.736
     BM 5 1973                                   3.697    1.574


                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  5 of  5

                                                                                
Station ID: 9449828                         PUBLICATION DATE:  07/15/2004
Name:       HANBURY POINT, SAN JUAN ISLAND                    
            WA
NOAA Chart: 18433                           Latitude:   48° 34.9' N (  48.58170)
USGS Quad:  ROCHE HARBOR                    Longitude: 123° 10.2' W (-123.17000)


                             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.

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Products available at 9449828 HANBURY POINT, SAN JUAN ISLAND, WA

Revised: 08/08/2018
NOAA / National Ocean Service
Web site owner: Center for Operational Oceanographic Products and Services