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Bench Mark Sheet for 8724963, DISMAL KEY, PUMPKIN 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Superseded Epoch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Small blue map location marker Unpublished bench mark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: 8724963                         PUBLICATION DATE:  04/25/2012
Name:       DISMAL KEY, PUMPKIN BAY                           
            FL
NOAA Chart: 11429                           Latitude:   25° 53.7' N (  25.89500)
USGS Quad:  PANTHER KEY                     Longitude:  81° 33.5' W ( -81.55830)


To reach the tidal bench marks proceed to the NW side of Dismal Key.  The bench
marks are located along the trail leading around the island.  The tide gage and
staff were located on a dock.


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


                 PRIMARY BENCH MARK STAMPING:  4963 A 1978
                         DESIGNATION:          872 4963 A TIDAL

MONUMENTATION:           Tidal Station disk                    VM#:        10975
AGENCY:                  National Ocean Survey (NOS)           IDB PID#:        
SETTING CLASSIFICATION:  Galvanized steel rod                  OPUS PID:        
LATITUDE:   25° 53.7' N (  25.89500)          LONGITUDE:  81° 33.5' W ( -81.55830)


The primary bench mark is a disk located 8.50 m (27.9 ft) SE of the shoreline,
7.56 m (24.8 ft) WSW of the SW corner of a wooden shed, 5.09 m (16.7 ft) south
of the SW shoreward end of a wooden dock, and 0.12 m (0.4 ft) ENE of a witness
post.  The bench mark is set 0.03 m (0.1 ft) below ground level, crimped to the
top of a galvanized steel rod driven 10 m (32 ft) to refusal, encased in a steel
protector pipe extending 0.34 m (1.1 ft) above the ground, and a concrete
kickblock.

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

                                                                                
Station ID: 8724963                         PUBLICATION DATE:  04/25/2012
Name:       DISMAL KEY, PUMPKIN BAY                           
            FL
NOAA Chart: 11429                           Latitude:   25° 53.7' N (  25.89500)
USGS Quad:  PANTHER KEY                     Longitude:  81° 33.5' W ( -81.55830)


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


                         BENCH MARK STAMPING:  4963 B 1978
                         DESIGNATION:          872 4963 B TIDAL

MONUMENTATION:           Tidal Station disk                    VM#:        10976
AGENCY:                  National Ocean Survey (NOS)           IDB PID#:        
SETTING CLASSIFICATION:  Galvanized steel rod                  OPUS PID:        
LATITUDE:   25° 53.7' N (  25.89500)          LONGITUDE:  81° 33.5' W ( -81.55830)


The bench mark is a disk located 38.65 m (126.8 ft) SSE of bench mark 4963 A
1978, 2.77 m (9.1 ft) WSW of the centerline of a path leading SE to a wooden
house, 1.58 m (5.2 ft) west of the north corner of a cistern, and 0.15 m (0.5
ft) NE of a witness post.  The bench mark is set 0.03 m (0.1 ft) below ground
level, crimped to the top of a galvanized steel rod driven 10 m (32 ft) to
refusal, encased in a steel protector pipe extending 0.34 m (1.1 ft) above the
ground, and a concrete kickblock.



                         BENCH MARK STAMPING:  4963 C 1978
                         DESIGNATION:          872 4963 C TIDAL

MONUMENTATION:           Tidal Station disk                    VM#:        10977
AGENCY:                  National Ocean Survey (NOS)           IDB PID#:        
SETTING CLASSIFICATION:  Galvanized steel rod                  OPUS PID:        
LATITUDE:   25° 53.7' N (  25.89500)          LONGITUDE:  81° 33.5' W ( -81.55830)


The bench mark is a disk located 51.21 m (168.0 ft) NE of bench mark 4963 D
1978, 2.13 m (7.0 ft) SE of the centerline of the trail, and 0.12 m (0.4 ft)
east of a witness post. The bench mark is set 0.9 m (0.3 ft) above ground level,
crimped to the top of a galvanized steel rod driven 10 m (32 ft) to refusal,
encased in a steel protector pipe extending 0.46 m (1.5 ft) above the ground,
and a concrete kickblock.

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

                                                                                
Station ID: 8724963                         PUBLICATION DATE:  04/25/2012
Name:       DISMAL KEY, PUMPKIN BAY                           
            FL
NOAA Chart: 11429                           Latitude:   25° 53.7' N (  25.89500)
USGS Quad:  PANTHER KEY                     Longitude:  81° 33.5' W ( -81.55830)


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


                         BENCH MARK STAMPING:  4963 D 1978
                         DESIGNATION:          872 4963 D TIDAL

MONUMENTATION:           Tidal Station disk                    VM#:        10978
AGENCY:                  National Ocean Survey (NOS)           IDB PID#:        
SETTING CLASSIFICATION:  Galvanized steel rod                  OPUS PID:        
LATITUDE:   25° 53.7' N (  25.89500)          LONGITUDE:  81° 33.5' W ( -81.55830)


The bench mark is a disk located 21.31 m (69.9 ft) east of bench mark 4963 E
1978, 8.84 m (29.0 ft) south of the centerline of the trail, and 0.15 m (0.5 ft)
east of a witness post. The bench mark is set 0.09 m (0.3 ft) above ground
level, crimped to the top of a galvanized steel rod driven 10 m (32 ft) to
refusal, encased in a steel protector pipe extending 0.18 m (0.6 ft) above the
ground, and a concrete kickblock.



                         BENCH MARK STAMPING:  4963 E 1978
                         DESIGNATION:          872 4963 E TIDAL

MONUMENTATION:           Tidal Station disk                    VM#:        10979
AGENCY:                  National Ocean Survey (NOS)           IDB PID#:        
SETTING CLASSIFICATION:  Galvanized steel rod                  OPUS PID:        
LATITUDE:   25° 53.7' N (  25.89500)          LONGITUDE:  81° 33.5' W ( -81.55830)


The bench mark is a disk located 5 m (16 ft) west of a 12-inch diameter
mangrove, 4.42 m (14.5 ft) south of the centerline of the trail, and 0.24 m (0.8
ft) north of a witness post.  The bench mark is set 0.09 m (0.3 ft) above ground
level, crimped to the top of a galvanized steel rod driven 12 m (40 ft) to
refusal, encased in a steel protector pipe extending 0.24 m (0.8 ft) above the
ground, and a concrete kickblock.

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

                                                                                
Station ID: 8724963                         PUBLICATION DATE:  04/25/2012
Name:       DISMAL KEY, PUMPKIN BAY                           
            FL
NOAA Chart: 11429                           Latitude:   25° 53.7' N (  25.89500)
USGS Quad:  PANTHER KEY                     Longitude:  81° 33.5' W ( -81.55830)


                            T I D A L   D A T U M S 


Tidal datums at DISMAL KEY, PUMPKIN BAY based on:

     LENGTH OF SERIES:      3 MONTHS
     TIME PERIOD:           March 1978 - May 1978
     TIDAL EPOCH:           1983-2001
     CONTROL TIDE STATION:  8725110 NAPLES, GULF OF MEXICO


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

     MEAN HIGHER HIGH WATER                     MHHW   =  1.150
     MEAN HIGH WATER                            MHW    =  1.060
     MEAN SEA LEVEL                             MSL    =  0.623
     MEAN TIDE LEVEL                            MTL    =  0.620
     MEAN LOW WATER                             MLW    =  0.181
     MEAN LOWER LOW WATER                       MLLW   =  0.000

North American Vertical Datum (NAVD88)

Bench Mark Elevation Information                In METERS above:

     Stamping or Designation                    MLLW        MHW

     4963 A 1978                                 1.311    0.251
     4963 B 1978                                 2.600    1.540
     4963 C 1978                                 2.194    1.134
     4963 D 1978                                 1.732    0.672
     4963 E 1978                                 2.157    1.097


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

                                                                                
Station ID: 8724963                         PUBLICATION DATE:  04/25/2012
Name:       DISMAL KEY, PUMPKIN BAY                           
            FL
NOAA Chart: 11429                           Latitude:   25° 53.7' N (  25.89500)
USGS Quad:  PANTHER KEY                     Longitude:  81° 33.5' W ( -81.55830)


                             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 8724963 DISMAL KEY, PUMPKIN BAY, FL

Revised: 10/15/2013
NOAA / National Ocean Service
Web site owner: Center for Operational Oceanographic Products and Services