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Bench Mark Sheet for 8722861, HILLSBORO INLET, INSIDE FL

Superseded Epoch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Small blue map location marker Unpublished bench mark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  7

                                                                                
Station ID: 8722861                         PUBLICATION DATE:  12/12/2003
Name:       HILLSBORO INLET, INSIDE                           
            FL
NOAA Chart: 11466                           Latitude:   26° 15.5' N (  26.25830)
USGS Quad:  BOCA RATON                      Longitude:  80°  4.9' W ( -80.08170)


To reach the tidal bench marks from the intersection of State Highways A1A and
814 in Pompano Beach, proceed 3.78 km (2.35 mi) north on State Highway A1A to a
black-topped road just north of the bridge over Hillsboro Inlet, then turn right
and proceed 0.08 km (0.05 mi) east on the black-topped road to the entrance gate
of the Hillsboro Inlet Private Club, then proceed 0.24 km (0.15 mi) past the
gate to the U.S. Coast Guard Station.  The bench marks are in the vicinity of
the Coast Guard station.  The tide gage was located at the south end of the
Coast Guard Light Station pier.  The tide staff was located on a piling about 5
m (15 ft) NE of the gage (the same staff was used for both stations 872 2861 and
872 2862).


                         T I D A L   B E N C H   M A R K S
                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  2 of  7

                                                                                
Station ID: 8722861                         PUBLICATION DATE:  12/12/2003
Name:       HILLSBORO INLET, INSIDE                           
            FL
NOAA Chart: 11466                           Latitude:   26° 15.5' N (  26.25830)
USGS Quad:  BOCA RATON                      Longitude:  80°  4.9' W ( -80.08170)


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


                 PRIMARY BENCH MARK STAMPING:  Z 311 1970
                         DESIGNATION:          Z 311

MONUMENTATION:           Bench Mark disk                       VM#:         5674
AGENCY:                  National Geodetic Survey (NGS)        IDB PID#:  AD2605
SETTING CLASSIFICATION:  Concrete flagpole base                OPUS PID:        
LATITUDE:   26° 15.6' N (  26.26000)          LONGITUDE:  80°  4.8' W ( -80.08000)


The primary bench mark is a disk set in the top of the SE corner of the concrete
flagpole base located on the U.S. Coast Guard station, 20 m (64 ft) east of the
centerline of the driveway, 7 m (23 ft) SE of the SW corner of the radio house,
7 m (22 ft) SW of the SW corner of the fence around the radio tower, and level
with the ground.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  3 of  7

                                                                                
Station ID: 8722861                         PUBLICATION DATE:  12/12/2003
Name:       HILLSBORO INLET, INSIDE                           
            FL
NOAA Chart: 11466                           Latitude:   26° 15.5' N (  26.25830)
USGS Quad:  BOCA RATON                      Longitude:  80°  4.9' W ( -80.08170)


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


                         BENCH MARK STAMPING:  P 314 1970
                         DESIGNATION:          P 314

MONUMENTATION:           Bench Mark disk                       VM#:         5672
AGENCY:                  National Geodetic Survey (NGS)        IDB PID#:  AD2606
SETTING CLASSIFICATION:  Copper-clad steel rod                 OPUS PID:        
LATITUDE:   26° 15.6' N (  26.26000)          LONGITUDE:  80°  4.9' W ( -80.08170)


The bench mark is a disk located along the east-west fence around the U.S. Coast
Guard station, 5 m (16 ft) NE of the NE corner of the north wing of a 1-story
frame house, 4 m (13 ft) west of the centerline of the driveway, 1 m (4 ft) west
of the west face of the west gate post, 0.18 m (0.6 ft) south of the fence line,
and 0.12 m (0.4 ft) south of a metal witness post.  The bench mark is set level
with the driveway, crimped to the top of a copper-clad steel rod driven 8.9 m
(29.2 ft) to refusal, and encased in a metal pipe.  Note:  The bench mark was
hit by heavy equipment and is severely bent.  Use with caution.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  4 of  7

                                                                                
Station ID: 8722861                         PUBLICATION DATE:  12/12/2003
Name:       HILLSBORO INLET, INSIDE                           
            FL
NOAA Chart: 11466                           Latitude:   26° 15.5' N (  26.25830)
USGS Quad:  BOCA RATON                      Longitude:  80°  4.9' W ( -80.08170)


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


                         BENCH MARK STAMPING:  Y 311 1970
                         DESIGNATION:          Y 311

MONUMENTATION:           Bench Mark disk                       VM#:         5673
AGENCY:                  National Geodetic Survey (NGS)        IDB PID#:  AD2604
SETTING CLASSIFICATION:  Concrete lighthouse base              OPUS PID:        
LATITUDE:   26° 15.5' N (  26.25830)          LONGITUDE:  80°  4.8' W ( -80.08000)


The bench mark is a disk set in the top of the east side of the concrete
lighthouse base located at the U.S. Coast Guard station, 51 m (168 ft) south of
Bench Mark Z 311 1970, 4.45 m (14.6 ft) west of the SE leg of the lighthouse,
and 3 m (10 ft) south of the SE corner of the lighthouse steps. Note:  The bench
mark is covered by a thin layer of tar and gravel.



                         BENCH MARK STAMPING:  16.770
                         DESIGNATION:          16.770 FLHD

MONUMENTATION:           Survey disk                           VM#:         5675
AGENCY:                  Florida Highway Department (FLHD)     IDB PID#:  AD2608
SETTING CLASSIFICATION:  Sidewalk                              OPUS PID:        
LATITUDE:   26° 15.7' N (  26.26170)          LONGITUDE:  80°  5.0' W ( -80.08330)


The bench mark is a disk set on the top of the sidewalk of the State Highway A1A
bridge located over Hillsboro Inlet, 60 m (198 ft) NE of the SW end of the
bridge, 5 m (15 ft) SE of the centerline of State Highway A1A, 0.3 m (1 ft) SE
of the NW edge of the sidewalk, and 0.3 m (1 ft) above the bridge floor.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  5 of  7

                                                                                
Station ID: 8722861                         PUBLICATION DATE:  12/12/2003
Name:       HILLSBORO INLET, INSIDE                           
            FL
NOAA Chart: 11466                           Latitude:   26° 15.5' N (  26.25830)
USGS Quad:  BOCA RATON                      Longitude:  80°  4.9' W ( -80.08170)


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


                         BENCH MARK STAMPING:  18.090
                         DESIGNATION:          18.090 FLHD

MONUMENTATION:           Survey disk                           VM#:         5676
AGENCY:                  Florida Highway Department (FLHD)     IDB PID#:  AD2607
SETTING CLASSIFICATION:  Curb                                  OPUS PID:        
LATITUDE:   26° 15.7' N (  26.26170)          LONGITUDE:  80°  5.0' W ( -80.08330)


The bench mark is a disk set in the top of the NW curb of the State Highway A1A
bridge located over Hillsboro Inlet, 4.75 m (15.6 ft) NW of the centerline of
State Highway A1A, 2 m (7 ft) SW of the NE end of the bannister, and 0.3 m (1
ft) above road level.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  6 of  7

                                                                                
Station ID: 8722861                         PUBLICATION DATE:  12/12/2003
Name:       HILLSBORO INLET, INSIDE                           
            FL
NOAA Chart: 11466                           Latitude:   26° 15.5' N (  26.25830)
USGS Quad:  BOCA RATON                      Longitude:  80°  4.9' W ( -80.08170)


                            T I D A L   D A T U M S 


Tidal datums at HILLSBORO INLET, INSIDE based on:

     LENGTH OF SERIES:      12 MONTHS
     TIME PERIOD:           May 1970 - April 1971
     TIDAL EPOCH:           1983-2001
     CONTROL TIDE STATION:  8723170 MIAMI BEACH (CITY PIER)


Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in METERS:

     HIGHEST OBSERVED WATER LEVEL (10/15/1970)         =  1.169
     MEAN HIGHER HIGH WATER                     MHHW   =  0.849
     MEAN HIGH WATER                            MHW    =  0.807
     North American Vertical Datum              NAVD88 =  0.715
     MEAN TIDE LEVEL                            MTL    =  0.428
     MEAN SEA LEVEL                             MSL    =  0.426
     MEAN LOW WATER                             MLW    =  0.048
     MEAN LOWER LOW WATER                       MLLW   =  0.000
     LOWEST  OBSERVED WATER LEVEL (04/26/1971)         = -0.342

North American Vertical Datum (NAVD88)

Bench Mark Elevation Information                In METERS above:

     Stamping or Designation                    MLLW        MHW

     Z 311 1970                                  4.096    3.289
     P 314 1970                                  3.761    2.954
     Y 311 1970                                  3.654    2.847
     16.770                                      5.336    4.529
     18.090                                      5.736    4.929


                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  7 of  7

                                                                                
Station ID: 8722861                         PUBLICATION DATE:  12/12/2003
Name:       HILLSBORO INLET, INSIDE                           
            FL
NOAA Chart: 11466                           Latitude:   26° 15.5' N (  26.25830)
USGS Quad:  BOCA RATON                      Longitude:  80°  4.9' W ( -80.08170)


                             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 8722861 HILLSBORO INLET, INSIDE, FL

Revised: 08/08/2018
NOAA / National Ocean Service
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