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Bench Mark Sheet for 8726574, BOCA CIEGA 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Superseded Epoch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Small blue map location marker Unpublished bench mark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.

Error: There is no bench mark map available for 8726574 BOCA CIEGA BAY, FL
Printable version

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
Datums Page                                                        Page  1 of  6

                                                                                
Station ID: 8726574                         PUBLICATION DATE:  09/16/2003
Name:       BOCA CIEGA BAY                                    
            FL
NOAA Chart: 11412                           Latitude:   27° 48.5' N (  27.80830)
USGS Quad:  SEMINOLE                        Longitude:  82° 47.7' W ( -82.79500)


To reach the tidal bench marks from the intersection of State Road 699 (Gulf
Boulevard) and Welch Causeway (State Road 666, 150th Avenue) in Madeira Beach,
proceed NE on Welch Causeway for 1.3 km (0.8 mi) to the Madeira Shopping Center
and McDonalds entrance, turn left and go 0.2 km (0.1 mi) to a stop sign at Black
Hawk Road, turn left and go 152 m (500 ft) to the end of the parking lot at
Brown Derby Restaurant (on the left) and American Legion Post 273 (on the
right).  The bench marks are between Brown Derby Restaurant and the Welch
Causeway bridge.  The tide gauge and staff were on the SE corner of the wooden
pier behind the post.  Access to the pier is through the American Legion Post
273 building.


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


                 PRIMARY BENCH MARK STAMPING:  6574 A 1976
                         DESIGNATION:          872 6574 A TIDAL

MONUMENTATION:           Tidal Station disk                    VM#:         6577
AGENCY:                  National Ocean Survey (NOS)           IDB PID#:  AG7426
SETTING CLASSIFICATION:  Concrete foundation                   OPUS PID:        
LATITUDE:   27° 48.6' N (  27.81000)          LONGITUDE:  82° 47.7' W ( -82.79500)


The primary bench mark is a disk set in the top of the foundation of the
American Legion Hall (Post 273) flagpole, 6.46 m (21.2 ft)  east of the front
door of the building, 4.11 m (13.5 ft) west of the curb of the road leading to
the building, and 0.15 m (0.5 ft) east of the flagpole.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  2 of  6

                                                                                
Station ID: 8726574                         PUBLICATION DATE:  09/16/2003
Name:       BOCA CIEGA BAY                                    
            FL
NOAA Chart: 11412                           Latitude:   27° 48.5' N (  27.80830)
USGS Quad:  SEMINOLE                        Longitude:  82° 47.7' W ( -82.79500)


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


                         BENCH MARK STAMPING:  6574 B 1976
                         DESIGNATION:          872 6574 B TIDAL

MONUMENTATION:           Tidal Station disk                    VM#:         6578
AGENCY:                  National Ocean Survey (NOS)           IDB PID#:  AG7424
SETTING CLASSIFICATION:  Concrete wing wall                    OPUS PID:        
LATITUDE:   27° 48.5' N (  27.80830)          LONGITUDE:  82° 47.7' W ( -82.79500)


The bench mark is a disk set in the NE wingwall of the Madeira Beach Causeway
bascule bridge, 10.76 m (35.3 ft) north of the bridge guardrail, 10.18 m (33.4
ft) NE of the NE end of the wingwall, 0.37 m (1.2 ft)  west of the east end of
the wingwall, and 4 m (13 ft) below the highway.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  3 of  6

                                                                                
Station ID: 8726574                         PUBLICATION DATE:  09/16/2003
Name:       BOCA CIEGA BAY                                    
            FL
NOAA Chart: 11412                           Latitude:   27° 48.5' N (  27.80830)
USGS Quad:  SEMINOLE                        Longitude:  82° 47.7' W ( -82.79500)


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


                         BENCH MARK STAMPING:  209 NO 2 RESET 1975
                         DESIGNATION:          209 2 RESET
                         ALIAS:                SRD 209

MONUMENTATION:           Survey disk                           VM#:         6580
AGENCY:                  Florida State Road Department (FLSRD) IDB PID#:  AG0166
SETTING CLASSIFICATION:  Concrete bridge guardrail             OPUS PID:        
LATITUDE:   27° 48.5' N (  27.80830)          LONGITUDE:  82° 47.6' W ( -82.79330)


The bench mark is a disk set in the top of the concrete bridge guardrail in the
NE corner of the Welch Causeway bridge, 1.1 km (0.7 mi) east of the intersection
of Welch Causeway and Gulf Boulevard.



                         BENCH MARK STAMPING:  6574 C 1990
                         DESIGNATION:          872 6574 C TIDAL

MONUMENTATION:           Tidal Station disk                    VM#:         6581
AGENCY:                  Florida Department of Natural Resources
                         (FLDNR)                               IDB PID#:  AG9392
SETTING CLASSIFICATION:  Concrete foundation                   OPUS PID:        
LATITUDE:   27° 48.5' N (  27.80830)          LONGITUDE:  82° 47.7' W ( -82.79500)


The bench mark is a disk set in the foundation that supports an old anchor and
two cannon barrels, 6.19 m (20.3 ft) ) SW of the bow of the fixed boat that is
Brown Derby Restaurant, 0.70 m (2.3 ft) north of the south side of a seawall,
and 0.27 m (0.9 ft) north of the south edge of the foundation.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  4 of  6

                                                                                
Station ID: 8726574                         PUBLICATION DATE:  09/16/2003
Name:       BOCA CIEGA BAY                                    
            FL
NOAA Chart: 11412                           Latitude:   27° 48.5' N (  27.80830)
USGS Quad:  SEMINOLE                        Longitude:  82° 47.7' W ( -82.79500)


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


                         BENCH MARK STAMPING:  WELCH JAX 1985
                         DESIGNATION:          WELCH JAX

MONUMENTATION:           Survey disk                           VM#:         6582
AGENCY:                  US Army Corps of Engineers (USCOE)    IDB PID#:  AG9393
SETTING CLASSIFICATION:  Sidewalk                              OPUS PID:        
LATITUDE:   27° 48.5' N (  27.80830)          LONGITUDE:  82° 47.7' W ( -82.79500)


The bench mark is a disk set in the sidewalk on the Welch Causeway bridge, 58.70
m (192.6 ft) NE of the point where the concrete ends and the metal lift begins,
43.80 m (143.7 ft) SE of the NE end of the bridge and of bench mark 209 NO 2
RESET 1975, and 8.11 m (26.6 ft) north of the centerline of Welch Causeway.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  5 of  6

                                                                                
Station ID: 8726574                         PUBLICATION DATE:  09/16/2003
Name:       BOCA CIEGA BAY                                    
            FL
NOAA Chart: 11412                           Latitude:   27° 48.5' N (  27.80830)
USGS Quad:  SEMINOLE                        Longitude:  82° 47.7' W ( -82.79500)


                            T I D A L   D A T U M S 


Tidal datums at BOCA CIEGA BAY based on:

     LENGTH OF SERIES:      1 MONTH
     TIME PERIOD:           August 1990 - August 1990
     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   =  0.736
     MEAN HIGH WATER                            MHW    =  0.648
     North American Vertical Datum              NAVD88 =  0.498
     MEAN SEA LEVEL                             MSL    =  0.396
     MEAN TIDE LEVEL                            MTL    =  0.392
     MEAN LOW WATER                             MLW    =  0.136
     MEAN LOWER LOW WATER                       MLLW   =  0.000

North American Vertical Datum (NAVD88)

Bench Mark Elevation Information                In METERS above:

     Stamping or Designation                    MLLW        MHW

     6574 A 1976                                 1.895    1.247
     6574 B 1976                                 1.480    0.832
     209 NO 2 RESET 1975                         6.419    5.771
     6574 C 1990                                 1.959    1.311
     WELCH JAX 1985                              7.647    6.999


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

                                                                                
Station ID: 8726574                         PUBLICATION DATE:  09/16/2003
Name:       BOCA CIEGA BAY                                    
            FL
NOAA Chart: 11412                           Latitude:   27° 48.5' N (  27.80830)
USGS Quad:  SEMINOLE                        Longitude:  82° 47.7' W ( -82.79500)


                             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 8726574 BOCA CIEGA BAY, FL

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