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Bench Mark Sheet for 8724992, ADDISON BAY 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Superseded Epoch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Small blue map location marker Unpublished bench mark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: 8724992                         PUBLICATION DATE:  11/13/2003
Name:       ADDISON BAY                                       
            FL
NOAA Chart: 11429                           Latitude:   25° 57.8' N (  25.96330)
USGS Quad:  MARCO ISLAND                    Longitude:  81° 39.9' W ( -81.66500)


To reach the tidal bench marks from the Moran's Barge Marina at the west end of
State Road 92 bridge over Big Marco River, proceed by boat NW along the marked
channel of the Big Marco River to the vicinity of marker 20, then proceed north
along Angelwing Creek to Addison Bay, then proceed NE in Addison Bay to a small
mangrove island, then head east to the mainland.  The bench marks are located on
the mainland along a cut line in the mangroves.  The tide gage and staff were
located between the small island and mainland on a small offshore platform.


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


                 PRIMARY BENCH MARK STAMPING:  4992 A 1978
                         DESIGNATION:          872 4992 A

MONUMENTATION:           Tidal Station disk                    VM#:         9763
AGENCY:                  National Ocean Service (NOS)          IDB PID#:        
SETTING CLASSIFICATION:  Galvanized steel rod                  OPUS PID:        
LATITUDE:   25° 57.8' N (  25.96330)          LONGITUDE:  81° 39.9' W ( -81.66500)


The primary bench mark is a disk located 198 m (650 ft) east of a small island,
1.83 m (6.0 ft) east of the west edge of the mangroves and 0.37 m (1.2 ft) west
of a witness post.  The bench mark is 0.27 m (0.9 ft) above ground level,
crimped to a galvanized steel rod driven 10.7 m (35 ft) to refusal, and encased
in a 4-inch steel pipe.

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

                                                                                
Station ID: 8724992                         PUBLICATION DATE:  11/13/2003
Name:       ADDISON BAY                                       
            FL
NOAA Chart: 11429                           Latitude:   25° 57.8' N (  25.96330)
USGS Quad:  MARCO ISLAND                    Longitude:  81° 39.9' W ( -81.66500)


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


                         BENCH MARK STAMPING:  4992 B 1978
                         DESIGNATION:          872 4992 B

MONUMENTATION:           Tidal Station disk                    VM#:         9764
AGENCY:                  National Ocean Service (NOS)          IDB PID#:        
SETTING CLASSIFICATION:  Galvanized steel rod                  OPUS PID:        
LATITUDE:   25° 57.8' N (  25.96330)          LONGITUDE:  81° 39.9' W ( -81.66500)


The bench mark is a disk located 26.55 m (87.1 ft) north of bench mark 4992 A
1978, 7 m (23 ft) east of the west edge of the mangroves, and 0.37 m (1.2 ft)
west of a witness post.  The bench mark is 0.37 m (1.2 ft) above the ground
level, crimped to a galvanized steel rod driven 9.8 m (32 ft) to refusal, and
encased in a 4-inch steel pipe.



                         BENCH MARK STAMPING:  4992 C 1978
                         DESIGNATION:          872 4992 C

MONUMENTATION:           Tidal Station disk                    VM#:         9765
AGENCY:                  National Ocean Service (NOS)          IDB PID#:        
SETTING CLASSIFICATION:  Galvanized steel rod                  OPUS PID:        
LATITUDE:   25° 57.8' N (  25.96330)          LONGITUDE:  81° 39.9' W ( -81.66500)


The bench mark is a disk located 36.94 m (121.2 ft) east of the west edge of the
mangroves, 33.95 m (111.4 ft) ESE of bench mark 4992 B 1978, 0.40 m (1.3 ft) NNW
of an old witness post, and 0.30 m (1.0 ft) NNW of a new witness post.  The
bench mark is 0.27 m (0.9 ft) above ground level, crimped to a galvanized steel
rod driven 11.6 m (38 ft) to refusal, and encased in a 4-inch steel pipe.

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

                                                                                
Station ID: 8724992                         PUBLICATION DATE:  11/13/2003
Name:       ADDISON BAY                                       
            FL
NOAA Chart: 11429                           Latitude:   25° 57.8' N (  25.96330)
USGS Quad:  MARCO ISLAND                    Longitude:  81° 39.9' W ( -81.66500)


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


                         BENCH MARK STAMPING:  4992 D 1978
                         DESIGNATION:          872 4992 D

MONUMENTATION:           Tidal Station disk                    VM#:         9766
AGENCY:                  National Ocean Service (NOS)          IDB PID#:        
SETTING CLASSIFICATION:  Galvanized steel rod                  OPUS PID:        
LATITUDE:   25° 57.8' N (  25.96330)          LONGITUDE:  81° 39.9' W ( -81.66500)


The bench mark is a disk located 46.48 m (152.5 ft) east of the west edge of the
mangroves, 18.62 m (61.1 ft) NE of bench mark 4992 C 1978, and 0.27 m (0.9 ft)
SW of a witness post.  The bench mark is 0.27 m (0.9 ft) above ground level,
crimped to a galvanized steel rod driven 10.4 m (34 ft) to refusal, and encased
in a 4-inch steel pipe.



                         BENCH MARK STAMPING:  4992 E 1978
                         DESIGNATION:          872 4992 E

MONUMENTATION:           Tidal Station disk                    VM#:         9767
AGENCY:                  National Ocean Service (NOS)          IDB PID#:        
SETTING CLASSIFICATION:  Galvanized steel rod                  OPUS PID:        
LATITUDE:   25° 57.8' N (  25.96330)          LONGITUDE:  81° 39.9' W ( -81.66500)


The bench mark is a disk located 57.76 m (189.5 ft) east of the west edge of the
mangroves, 14.39 m (47.2 ft) NNE of Bench Mark 4992 D 1978, 9 m (30 ft) SW of
the SE end of a small creek, and 0.55 m (1.8 ft) SW of a witness post.  The
bench mark is 0.40 m (1.3 ft) above ground level, crimped to a galvanized steel
rod driven 9.8 m (32 ft) to refusal, and encased in a 4-inch steel pipe.

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

                                                                                
Station ID: 8724992                         PUBLICATION DATE:  11/13/2003
Name:       ADDISON BAY                                       
            FL
NOAA Chart: 11429                           Latitude:   25° 57.8' N (  25.96330)
USGS Quad:  MARCO ISLAND                    Longitude:  81° 39.9' W ( -81.66500)


                            T I D A L   D A T U M S 


Tidal datums at ADDISON BAY based on:

     LENGTH OF SERIES:      4 MONTHS
     TIME PERIOD:           July 1978 - October 1978
     TIDAL EPOCH:           1983-2001
     CONTROL TIDE STATION:  8724967 MARCO ISLAND, CAXAMBAS PASS


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

     MEAN HIGHER HIGH WATER                     MHHW   =  0.884
     MEAN HIGH WATER                            MHW    =  0.815
     MEAN SEA LEVEL                             MSL    =  0.500
     MEAN TIDE LEVEL                            MTL    =  0.487
     MEAN LOW WATER                             MLW    =  0.159
     MEAN LOWER LOW WATER                       MLLW   =  0.000

North American Vertical Datum (NAVD88)

Bench Mark Elevation Information                In METERS above:

     Stamping or Designation                    MLLW        MHW

     4992 A 1978                                 0.860    0.045
     4992 B 1978                                 0.999    0.184
     4992 C 1978                                 0.959    0.144
     4992 D 1978                                 1.014    0.199
     4992 E 1978                                 1.084    0.269


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

                                                                                
Station ID: 8724992                         PUBLICATION DATE:  11/13/2003
Name:       ADDISON BAY                                       
            FL
NOAA Chart: 11429                           Latitude:   25° 57.8' N (  25.96330)
USGS Quad:  MARCO ISLAND                    Longitude:  81° 39.9' W ( -81.66500)


                             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 8724992 ADDISON BAY, FL

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