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Bench Mark Sheet for 8724489, BIG COPPITT KEY 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Superseded Epoch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Small blue map location marker Unpublished bench mark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: 8724489                         PUBLICATION DATE:  02/05/2004
Name:       BIG COPPITT KEY                                   
            FL
NOAA Chart: 11445                           Latitude:   24° 36.1' N (  24.60170)
USGS Quad:  BOCA CHICA KEY                  Longitude:  81° 39.3' W ( -81.65500)


To reach the tidal bench marks from the Catholic Church in Key West, proceed NE
on U.S. Highway 1 for 15.9 km (9.9 mi) to Diamond Road, then turn left and
proceed north on Diamond Road for 0.3 km (0.2 mi) to the end of the road.  The
bench marks are located along Diamond Road.  The tide gage and staff were
located off the north end of Diamond Road.


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


                 PRIMARY BENCH MARK STAMPING:  NO 4 1974
                         DESIGNATION:          872 4489 TIDAL 4

MONUMENTATION:           Tidal Station disk                    VM#:        11038
AGENCY:                  National Ocean Survey (NOS)           IDB PID#:  AA0989
SETTING CLASSIFICATION:  Concrete monument                     OPUS PID:        
LATITUDE:   24° 36.2' N (  24.60330)          LONGITUDE:  81° 39.3' W ( -81.65500)


The primary bench mark is a disk set in a concrete post near the NW property
corner at 7 Diamond Road, 9 m (31 ft) east of the centerline of the road, and
0.06 m (0.2 ft) above the ground.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  2 of  7

                                                                                
Station ID: 8724489                         PUBLICATION DATE:  02/05/2004
Name:       BIG COPPITT KEY                                   
            FL
NOAA Chart: 11445                           Latitude:   24° 36.1' N (  24.60170)
USGS Quad:  BOCA CHICA KEY                  Longitude:  81° 39.3' W ( -81.65500)


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


                         BENCH MARK STAMPING:  U 70 RESET 1939
                         DESIGNATION:          U 70 RESET

MONUMENTATION:           Bench Mark disk                       VM#:        11033
AGENCY:                  US Coast and Geodetic Survey
                         (USC&GS)                              IDB PID#:  AA0109
SETTING CLASSIFICATION:  Concrete wing wall                    OPUS PID:        
LATITUDE:   24° 35.6' N (  24.59330)          LONGITUDE:  81° 39.9' W ( -81.66500)


The bench mark is a disk set in the top of the SE concrete wing wall at the NE
end of the Rockland Channel Viaduct, 5.03 m (16.5 ft) SE of the centerline of
U.S. Highway 1, and 0.76 m (2.5 ft) below highway level.



                         BENCH MARK STAMPING:  4489 F 1982
                         DESIGNATION:          872 4489 F TIDAL

MONUMENTATION:           Tidal Station disk                    VM#:        11034
AGENCY:                  National Ocean Survey (NOS)           IDB PID#:  AA0993
SETTING CLASSIFICATION:  Concrete and limerock pillar          OPUS PID:        
LATITUDE:   24° 35.9' N (  24.59830)          LONGITUDE:  81° 39.2' W ( -81.65330)


The bench mark is a disk set vertically in the west side of a 1 m (3 ft) square
and 2.44 m (8.0 ft) high concrete and limerock pillar at the junction of U.S.
Highway 1 and Diamond Road, 26.64 m (87.4 ft) ESE of the SE fence corner at
Southern Furniture Sales, 21.92 m (71.9 ft) NW of the centerline of U.S. Highway
1, 7.41 m (24.3 ft) east of the centerline of Diamond Road, and 0.21 m (0.7 ft)
above the ground.

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

                                                                                
Station ID: 8724489                         PUBLICATION DATE:  02/05/2004
Name:       BIG COPPITT KEY                                   
            FL
NOAA Chart: 11445                           Latitude:   24° 36.1' N (  24.60170)
USGS Quad:  BOCA CHICA KEY                  Longitude:  81° 39.3' W ( -81.65500)


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


                         BENCH MARK STAMPING:  NO 1 1974
                         DESIGNATION:          872 4489 TIDAL 1

MONUMENTATION:           Tidal Station disk                    VM#:        11035
AGENCY:                  National Ocean Survey (NOS)           IDB PID#:  AA0990
SETTING CLASSIFICATION:  Concrete monument                     OPUS PID:        
LATITUDE:   24° 36.1' N (  24.60170)          LONGITUDE:  81° 39.3' W ( -81.65500)


The bench mark is a disk set in a concrete post located near the north end of
Diamond Road on the extended centerline, 6 m (19 ft) north of a power pole and 2
m (5 ft) north of a guide wire. 



                         BENCH MARK STAMPING:  NO 2 1974
                         DESIGNATION:          872 4489 TIDAL 2

MONUMENTATION:           Tidal Station disk                    VM#:        11036
AGENCY:                  National Ocean Survey (NOS)           IDB PID#:  AA0991
SETTING CLASSIFICATION:  Concrete monument                     OPUS PID:        
LATITUDE:   24° 36.1' N (  24.60170)          LONGITUDE:  81° 39.3' W ( -81.65500)


The bench mark is a disk set in a concrete post near the north end of Diamond
Road on the exteded centerline, 1 m (4 ft) south of a power pole. 

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

                                                                                
Station ID: 8724489                         PUBLICATION DATE:  02/05/2004
Name:       BIG COPPITT KEY                                   
            FL
NOAA Chart: 11445                           Latitude:   24° 36.1' N (  24.60170)
USGS Quad:  BOCA CHICA KEY                  Longitude:  81° 39.3' W ( -81.65500)


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


                         BENCH MARK STAMPING:  NO 5 1974
                         DESIGNATION:          872 4489 TIDAL 5

MONUMENTATION:           Tidal Station disk                    VM#:        11039
AGENCY:                  National Ocean Survey (NOS)           IDB PID#:  AA1636
SETTING CLASSIFICATION:  Concrete monument                     OPUS PID:        
LATITUDE:   24° 36.2' N (  24.60330)          LONGITUDE:  81° 39.3' W ( -81.65500)


The bench mark is a disk set along Diamond Road, about halfway between U.S.
Highway 1 and the end of Diamond Road, 6 m (20 ft) west of the Diamond Road
centerline, and 1 m (2 ft) north of power pole #BC 21-150.



                         BENCH MARK STAMPING:  4489 G 1986
                         DESIGNATION:          872 4489 G TIDAL

MONUMENTATION:           Tidal Station disk                    VM#:        11310
AGENCY:                  National Ocean Service (NOS)          IDB PID#:  AA1637
SETTING CLASSIFICATION:  Concrete base for a metal power pole  OPUS PID:        
LATITUDE:   24° 35.9' N (  24.59830)          LONGITUDE:  81° 39.2' W ( -81.65330)


The bench mark is a disk set in the north edge of the concrete base for a metal
power pole, 51.82 m (170.0 ft) WSW of the extended centerline of Aquamarine
Drive, 46.33 m (152.0 ft) ESE of bench mark 4489 F 1982, 43.89 m (144.0 ft) ENE
of the NE corner of a fence around an electrical transmission station, 12.41 m
(40.7 ft) SSE of the centerline of U.S. Highway 1, and 1 m (3 ft) below the
level of the highway.

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

                                                                                
Station ID: 8724489                         PUBLICATION DATE:  02/05/2004
Name:       BIG COPPITT KEY                                   
            FL
NOAA Chart: 11445                           Latitude:   24° 36.1' N (  24.60170)
USGS Quad:  BOCA CHICA KEY                  Longitude:  81° 39.3' W ( -81.65500)


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


                         BENCH MARK STAMPING:  4489 H 1986
                         DESIGNATION:          872 4489 H TIDAL

MONUMENTATION:           Tidal Station disk                    VM#:        11311
AGENCY:                  National Ocean Service (NOS)          IDB PID#:  AA1638
SETTING CLASSIFICATION:  Concrete base for a metal power pole  OPUS PID:        
LATITUDE:   24° 35.8' N (  24.59670)          LONGITUDE:  81° 39.1' W ( -81.65170)


The bench mark is a disk set in the north edge of the concrete base for a metal
power  pole, 0.24 km (0.15 mi) NE of bench mark 4489 F 1986, 13.11 m (43.0 ft)
SSE of the centerline of U.S. Highway 1, 9.91 m (32.5 ft) ENE of the centerline
of County Road 941, and 0.61 m (2.0 ft) below the level of road.

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

                                                                                
Station ID: 8724489                         PUBLICATION DATE:  02/05/2004
Name:       BIG COPPITT KEY                                   
            FL
NOAA Chart: 11445                           Latitude:   24° 36.1' N (  24.60170)
USGS Quad:  BOCA CHICA KEY                  Longitude:  81° 39.3' W ( -81.65500)


                            T I D A L   D A T U M S 


Tidal datums at BIG COPPITT KEY based on:

     LENGTH OF SERIES:      2 MONTHS
     TIME PERIOD:           April 1974 - May 1974
     TIDAL EPOCH:           1983-2001
     CONTROL TIDE STATION:  8724580 KEY WEST


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

     MEAN HIGHER HIGH WATER                     MHHW   =  0.481
     MEAN HIGH WATER                            MHW    =  0.389
     North American Vertical Datum              NAVD88 =  0.354
     MEAN TIDE LEVEL                            MTL    =  0.206
     MEAN SEA LEVEL                             MSL    =  0.166
     MEAN LOW WATER                             MLW    =  0.023
     MEAN LOWER LOW WATER                       MLLW   =  0.000

North American Vertical Datum (NAVD88)

Bench Mark Elevation Information                In METERS above:

     Stamping or Designation                    MLLW        MHW

     NO 4 1974                                   1.507    1.118
     U 70 RESET 1939                             2.374    1.985
     4489 F 1982                                 2.406    2.017
     NO 1 1974                                   1.358    0.969
     NO 2 1974                                   1.431    1.042
     NO 5 1974                                   1.571    1.182
     4489 G 1986                                 1.223    0.834
     4489 H 1986                                 2.036    1.647


Foot Notes:

Bench marks U 70 RESET 1939. P 272 1966, 4489 G 1986 and  4489 H 1986 are based
on one differential leveling connection and do not meet the quality control
standards of the NOS. Therefore, caution should be used when deriving
elevationsfor these marks. 

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

                                                                                
Station ID: 8724489                         PUBLICATION DATE:  02/05/2004
Name:       BIG COPPITT KEY                                   
            FL
NOAA Chart: 11445                           Latitude:   24° 36.1' N (  24.60170)
USGS Quad:  BOCA CHICA KEY                  Longitude:  81° 39.3' W ( -81.65500)


                             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 8724489 BIG COPPITT KEY, FL

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