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Bench Mark Sheet for 8727151, BAYPORT 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Superseded Epoch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Small blue map location marker Unpublished bench mark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  5

                                                                                
Station ID: 8727151                         PUBLICATION DATE:  12/12/2003
Name:       BAYPORT                                           
            FL
NOAA Chart: 11409                           Latitude:   28° 32.0' N (  28.53330)
USGS Quad:  BAYPORT                         Longitude:  82° 39.0' W ( -82.65000)


To reach the tidal bench marks from the intersection of U.S. Highway 19 and
State Road 50 in Weeki Wachee Springs, proceed west on State Road 50  for 10.0
km (6.2 mi) to its end at the County Park at Bayport. The bench marks are
located in area around the park.  The tide gage and staff were located on the
park fishing pier.


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


                 PRIMARY BENCH MARK STAMPING:  7151 D 1978
                         DESIGNATION:          872 7151 D TIDAL

MONUMENTATION:           Tidal Station disk                    VM#:         7743
AGENCY:                  National Ocean Survey (NOS)           IDB PID#:  AL7725
SETTING CLASSIFICATION:  Stainless steel rod                   OPUS PID:        
LATITUDE:   28° 32.1' N (  28.53500)          LONGITUDE:  82° 39.0' W ( -82.65000)


The primary bench mark is a disk located 11.70 m (38.4 ft) west of the the
centerline of the road, 2.01 m (6.6 ft) east of a concrete retaining wall, and
1.01 m (3.3 ft) north of a witness post.  The bench mark is crimped to the top
of a stainless steel rod driven 3.4 m (11 ft) to refusal and encased in PVC pipe
and a concrete kickblock.

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

                                                                                
Station ID: 8727151                         PUBLICATION DATE:  12/12/2003
Name:       BAYPORT                                           
            FL
NOAA Chart: 11409                           Latitude:   28° 32.0' N (  28.53330)
USGS Quad:  BAYPORT                         Longitude:  82° 39.0' W ( -82.65000)


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


                         BENCH MARK STAMPING:  7151 A 1978
                         DESIGNATION:          872 7151 A TIDAL

MONUMENTATION:           Tidal Station disk                    VM#:         7740
AGENCY:                  National Ocean Survey (NOS)           IDB PID#:  AL7724
SETTING CLASSIFICATION:  Concrete monument                     OPUS PID:        
LATITUDE:   28° 32.2' N (  28.53670)          LONGITUDE:  82° 39.0' W ( -82.65000)


The bench mark is a disk set in the top of a concrete monument located 30.48 m
(100.0 ft) north of a concrete bulkhead along a canal, 16.89 m (55.4 ft) west of
the SW corner of a covered picnic shelter, 4.57 m (15.0 ft) east of the
centerline of the paved entrance road, 2.13 m (7.0 ft) NE of the SW corner of
the curbing around the picnic area, 1.68 m (5.5 ft) SW of the westernmost palm
tree in the picnic area, and 0.03 m (0.1 ft) below ground level.  



                         BENCH MARK STAMPING:  7151 B 1978
                         DESIGNATION:          872 7151 B TIDAL

MONUMENTATION:           Tidal Station disk                    VM#:         7741
AGENCY:                  National Ocean Survey (NOS)           IDB PID#:  AL7722
SETTING CLASSIFICATION:  Concrete monument                     OPUS PID:        
LATITUDE:   28° 32.2' N (  28.53670)          LONGITUDE:  82° 39.0' W ( -82.65000)


The bench mark is a disk set in top of a concrete monument located in a
triangular grass median strip on the south side of the park entrance road, 98 m
(323 ft) NE of bench mark 7151 A 1978, 22.68 m (74.4 ft) NNE of the NE corner of
the restroom building, 4.97 m (16.3 ft) south of the centerline of the entrance
road, 4.21 m (13.8 ft) west of a palm tree, 2.99 m (9.8 ft) east of a 0.61 m
(2.0 ft) pine tree, 0.15 m (1.5 ft) south of a witness post, and 0.03 m (0.1 ft)
below ground level.

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

                                                                                
Station ID: 8727151                         PUBLICATION DATE:  12/12/2003
Name:       BAYPORT                                           
            FL
NOAA Chart: 11409                           Latitude:   28° 32.0' N (  28.53330)
USGS Quad:  BAYPORT                         Longitude:  82° 39.0' W ( -82.65000)


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


                         BENCH MARK STAMPING:  7151 C 1978
                         DESIGNATION:          872 7151 C TIDAL

MONUMENTATION:           Tidal Station disk                    VM#:         7742
AGENCY:                  National Ocean Survey (NOS)           IDB PID#:  AL7723
SETTING CLASSIFICATION:  Concrete monument                     OPUS PID:        
LATITUDE:   28° 32.2' N (  28.53670)          LONGITUDE:  82° 39.0' W ( -82.65000)


The bench mark is a disk set in top of a concrete monument located 55.02 m
(180.5 ft) SSW of bench mark 7151 B 1978, 41.03 m (134.6 ft) east of the SE
corner of the westernmost of two boat ramps, 26.55 m (87.1 ft) south of the SE
corner of the restroom buildings, 4.57 m (15.0 ft) west of the west edge of the
easternmost boat ramp, 2.68 m (8.8 ft) north of a concrete bulkhead for the
canal, and 0.06 m (0.2 ft) below ground level.



                         BENCH MARK STAMPING:  50 ERS TT 1952 3.9
                         DESIGNATION:          50 ERS TT

MONUMENTATION:           Survey disk                           VM#:         7744
AGENCY:                  U.S. Geological Survey (USGS)         IDB PID#:  AL7726
SETTING CLASSIFICATION:  Concrete bulkhead                     OPUS PID:        
LATITUDE:   28° 32.0' N (  28.53330)          LONGITUDE:  82° 39.0' W ( -82.65000)


The bench mark is a disk set in the concrete bulkhead located at the west end of
the paved parking area at the end of the road, 7.74 m (25.4 ft) south of the
parking area, 5.79 m (19.0 ft) west of the NW end of the fishing pier, and 0.43
m (1.4 ft) north of the south edge of the concrete bulkhead.

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

                                                                                
Station ID: 8727151                         PUBLICATION DATE:  12/12/2003
Name:       BAYPORT                                           
            FL
NOAA Chart: 11409                           Latitude:   28° 32.0' N (  28.53330)
USGS Quad:  BAYPORT                         Longitude:  82° 39.0' W ( -82.65000)


                            T I D A L   D A T U M S 


Tidal datums at BAYPORT based on:

     LENGTH OF SERIES:      4 MONTHS
     TIME PERIOD:           December 1978 - March 1979
     TIDAL EPOCH:           1983-2001
     CONTROL TIDE STATION:  8726724 CLEARWATER BEACH, GULF OF MEXICO


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

     MEAN HIGHER HIGH WATER                     MHHW   =  0.963
     MEAN HIGH WATER                            MHW    =  0.846
     North American Vertical Datum              NAVD88 =  0.561
     MEAN TIDE LEVEL                            MTL    =  0.492
     MEAN SEA LEVEL                             MSL    =  0.480
     MEAN LOW WATER                             MLW    =  0.137
     MEAN LOWER LOW WATER                       MLLW   =  0.000

North American Vertical Datum (NAVD88)

Bench Mark Elevation Information                In METERS above:

     Stamping or Designation                    MLLW        MHW

     7151 D 1978                                 1.569    0.723
     7151 A 1978                                 2.100    1.254
     7151 B 1978                                 2.061    1.215
     7151 C 1978                                 1.604    0.758
     50 ERS TT 1952 3.9                          1.479    0.633


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

                                                                                
Station ID: 8727151                         PUBLICATION DATE:  12/12/2003
Name:       BAYPORT                                           
            FL
NOAA Chart: 11409                           Latitude:   28° 32.0' N (  28.53330)
USGS Quad:  BAYPORT                         Longitude:  82° 39.0' W ( -82.65000)


                             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 8727151 BAYPORT, FL

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