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Bench Mark Sheet for 8724996, MCILVAINE 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Superseded Epoch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Small blue map location marker Unpublished bench mark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: 8724996                         PUBLICATION DATE:  02/26/2004
Name:       MCILVAINE BAY                                     
            FL
NOAA Chart: 11429                           Latitude:   25° 59.1' N (  25.98500)
USGS Quad:  MARCO ISLAND                    Longitude:  81° 42.1' W ( -81.70170)


To reach the tidal bench marks from the intersection of U.S. Highway 41 (Tamiami
Trail East) and State Road 951 (Isle of Capri Road) south of Naples, proceed
south on State Road 951 for 8.0 km (5.0 mi) to the bridge over McIlvaine Bay. 
The bench marks are on the bridge and to the SE.  The tide gage and staff were
located on a small platform east of the SE corner of the bridge.


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


                 PRIMARY BENCH MARK STAMPING:  4996 E 1978
                         DESIGNATION:          872 4996 E TIDAL

MONUMENTATION:           Tidal Station disk                    VM#:         9770
AGENCY:                  National Ocean Survey (NOS)           IDB PID#:  AC3380
SETTING CLASSIFICATION:  Galvanized steel rod                  OPUS PID:        
LATITUDE:   25° 59.1' N (  25.98500)          LONGITUDE:  81° 42.1' W ( -81.70170)


The primary bench mark is a disk located about 0.24 km (0.15 mi) south of the
bridge, 108 m (354 ft) south of Bench Mark 4996 D 1978, 13 m (44 ft) east of the
centerline of State Road 951, and 0.30 m (1.0 ft)  west of a witness post.  The
bench mark is set 1 m (3 ft) below the road, crimped to the top of a galvanized
steel rod driven 9.8 m (32 ft) to refusal, and encased in a pipe recessed 9 cm
(0.3 ft).

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

                                                                                
Station ID: 8724996                         PUBLICATION DATE:  02/26/2004
Name:       MCILVAINE BAY                                     
            FL
NOAA Chart: 11429                           Latitude:   25° 59.1' N (  25.98500)
USGS Quad:  MARCO ISLAND                    Longitude:  81° 42.1' W ( -81.70170)


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


                         BENCH MARK STAMPING:  4996 C 1978
                         DESIGNATION:          872 4996 C TIDAL

MONUMENTATION:           Tidal Station disk                    VM#:         9768
AGENCY:                  National Ocean Survey (NOS)           IDB PID#:  AC3378
SETTING CLASSIFICATION:  Concrete monument                     OPUS PID:        
LATITUDE:   25° 59.2' N (  25.98670)          LONGITUDE:  81° 42.1' W ( -81.70170)


The bench mark is a disk set in a concrete monument 76 m (249 ft) south of the
SE corner of the bridge, 9 m (29 ft) east of the State Road 951 centerline, 0.30
m (1.0 ft) west of a metal witness post, 1 m (2 ft) below the road, and 0.15 m
(0.5 ft) below ground level.



                         BENCH MARK STAMPING:  4996 D 1978
                         DESIGNATION:          872 4996 D TIDAL

MONUMENTATION:           Tidal Station disk                    VM#:         9769
AGENCY:                  National Ocean Survey (NOS)           IDB PID#:  AC3379
SETTING CLASSIFICATION:  Concrete monument                     OPUS PID:        
LATITUDE:   25° 59.2' N (  25.98670)          LONGITUDE:  81° 42.1' W ( -81.70170)


The bench mark is a disk set in a concrete monument 137 m (450 ft) south of the
south end of the bridge, 61 m (200 ft) south of Bench Mark 4996 C 1978, 8 m (27
ft) east of the centerline of State Road 951, 0.30 m (1.0 ft) west of a witness
post, 1 m (3 ft) below the road, and 12 cm (0.4 ft)  below ground level.

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

                                                                                
Station ID: 8724996                         PUBLICATION DATE:  02/26/2004
Name:       MCILVAINE BAY                                     
            FL
NOAA Chart: 11429                           Latitude:   25° 59.1' N (  25.98500)
USGS Quad:  MARCO ISLAND                    Longitude:  81° 42.1' W ( -81.70170)


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


                         BENCH MARK STAMPING:  4996 A
                         DESIGNATION:          872 4996 A TIDAL

MONUMENTATION:           Bench Mark disk                       VM#:         9771
AGENCY:                  Florida Highway Department (FLHD)     IDB PID#:  AC3377
SETTING CLASSIFICATION:  Bridge abutment wing wall             OPUS PID:        
LATITUDE:   25° 59.2' N (  25.98670)          LONGITUDE:  81° 42.1' W ( -81.70170)


The bench mark is a disk set in the SE bridge abutment wingwall, 61 m (200 ft)
SSE of bench mark 4996 B, 6 m (19 ft) east of the centerline of State Road 951,
and level with the road.



                         BENCH MARK STAMPING:  4996 B
                         DESIGNATION:          872 4996 B TIDAL

MONUMENTATION:           Bench Mark disk                       VM#:         9772
AGENCY:                  Florida Highway Department (FLHD)     IDB PID#:  AC3376
SETTING CLASSIFICATION:  Bridge abutment wing wall             OPUS PID:        
LATITUDE:   25° 59.3' N (  25.98830)          LONGITUDE:  81° 42.1' W ( -81.70170)


The bench mark is a disk set in the NW bridge abutment wing wall, 6 m (20 ft)
west of the centerline of State Road 951, and level with the road.

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

                                                                                
Station ID: 8724996                         PUBLICATION DATE:  02/26/2004
Name:       MCILVAINE BAY                                     
            FL
NOAA Chart: 11429                           Latitude:   25° 59.1' N (  25.98500)
USGS Quad:  MARCO ISLAND                    Longitude:  81° 42.1' W ( -81.70170)


                            T I D A L   D A T U M S 


Tidal datums at MCILVAINE BAY based on:

     LENGTH OF SERIES:      5 MONTHS
     TIME PERIOD:           August 1978 - December 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   =  0.795
     MEAN HIGH WATER                            MHW    =  0.722
     North American Vertical Datum              NAVD88 =  0.618
     MEAN SEA LEVEL                             MSL    =  0.437
     MEAN TIDE LEVEL                            MTL    =  0.430
     MEAN LOW WATER                             MLW    =  0.138
     MEAN LOWER LOW WATER                       MLLW   =  0.000

North American Vertical Datum (NAVD88)

Bench Mark Elevation Information                In METERS above:

     Stamping or Designation                    MLLW        MHW

     4996 E 1978                                 1.178    0.456
     4996 C 1978                                 1.210    0.488
     4996 D 1978                                 1.127    0.405
     4996 A                                      3.978    3.256
     4996 B                                      3.973    3.251


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

                                                                                
Station ID: 8724996                         PUBLICATION DATE:  02/26/2004
Name:       MCILVAINE BAY                                     
            FL
NOAA Chart: 11429                           Latitude:   25° 59.1' N (  25.98500)
USGS Quad:  MARCO ISLAND                    Longitude:  81° 42.1' W ( -81.70170)


                             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 8724996 MCILVAINE BAY, FL

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