Superseded Bench Mark Sheet for 8729169, SHELL POINT, WEST BAY FL

Present Epoch

Printable version

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
Datums Page                                                        Page  1 of  4

                                                   PUBLICATION DATE:  06/11/1984
Station ID: 8729169                                SUPERCEDED DATE:   04/21/2003
Name:       SHELL POINT, WEST BAY                             
            FLORIDA
NOAA Chart: 11389                                  Latitude:         30° 12.9' N
USGS Quad:  PANAMA CITY                            Longitude:        85° 44.4' W


To reach the tidal bench marks from the boat launch at the Carl Grey Park on the
NE side of the Hathaway Bridge over West Bay, proceed 1.72 nautical miles (2.8
m) NNW to Shell Point.  The gage site was 600 feet (183 m) SE of the point.  The
bench marks are in the near area.


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


                 PRIMARY BENCH MARK STAMPING:  9169 A 1976

MONUMENTATION:           Survey Disk                               VM#:    10039
AGENCY:                                                            PID:         
SETTING CLASSIFICATION:  Copper-Coated Steel Rod


The bench mark is 139.0 feet (42.4 m) NNE of Bench Mark 9169 B 1976, 30.0 feet
(9.1 m) west of the shoreline, 25.1 feet (7.6 m) south of a lone oak tree and
0.4 feet (0.1 m) east of a witness post, set on top of a 0.6 foot (0.2 m)
diameter copper-coated steel rod driven 40.0 feet (12.2 m) to refusal and
encased in a PVC protector pipe and concrete kickblock, 0.5 feet (0.15 m) below
ground surface.



                         BENCH MARK STAMPING:  9169 B 1976

MONUMENTATION:           Survey Disk                               VM#:    10040
AGENCY:                                                            PID:         
SETTING CLASSIFICATION:  Copper-Coated Steel Rod


The bench mark is 318.0 feet (96.9 m) NE of Bench Mark 9169 C 1976, 139.0 feet
(42.4 m) SSW of Bench Mark 9169 A 1976, 27.6 feet (8.4 m) west of the shoreline,
0.3 foot (0.09 m) east of a small single oak tree and 0.2 foot (0.06 m) NE of a
witness post, set on top of a 0.6 foot (0.2 m) diameter copper-coated steel rod
driven 40.0 feet (12.2 m) and encased in a PVC protector pipe and concrete
kickblock, 0.5 feet (0.1 m) below ground surface.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  2 of  4

                                                   PUBLICATION DATE:  06/11/1984
Station ID: 8729169                                SUPERCEDED DATE:   04/21/2003
Name:       SHELL POINT, WEST BAY                             
            FLORIDA
NOAA Chart: 11389                                  Latitude:         30° 12.9' N
USGS Quad:  PANAMA CITY                            Longitude:        85° 44.4' W


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


                         BENCH MARK STAMPING:  9169 C 1976

MONUMENTATION:           Survey Disk                               VM#:    10041
AGENCY:                                                            PID:         
SETTING CLASSIFICATION:  Copper-Coated Steel Rod


The bench mark is 318.0 feet (96.9 m) SW of Bench Mark 9169 B 1976, 309.0 feet
(94.2 m) SSW of  Bench Mark 9169 D 1976, 200.0 feet (61.0 m) SE of a line of
trees, 100.0 feet (30.5 m) west of the shoreline and 0.4 feet (0.1 m) north of a
witness post, 0.5 feet (0.2 m) below ground surface.



                         BENCH MARK STAMPING:  9169 D 1976

MONUMENTATION:           Survey Disk                               VM#:    10042
AGENCY:                                                            PID:         
SETTING CLASSIFICATION:  Copper-Coated Steel Rod


The bench mark is 309.0 feet (94.2 m) north of Bench Mark 9169 C 1976, 150 feet
(45.7 m) west of the shoreline, 35.7 feet (10.9 m) east of the center of a small
group of scrub oak, and 0.4 foot (0.11 m) south of a witness post, set on top of
a 0.6 foot (0.2 m) diameter copper-coated steel rod driven 32.0 feet (9.8 m) to
refusal and encased in a PVC protector pipe an concrete kickblock, 0.5 feet (0.1
m) below ground surface.



                         BENCH MARK STAMPING:  WEST BAY PT 2 NO 2

MONUMENTATION:           Survey Disk                               VM#:    10043
AGENCY:                                                            PID#:  AC8610
SETTING CLASSIFICATION:  Concrete Post


The bench mark is north of a line of cedar trees, 157.5 feet (48.0 m) NW of the
NE end of a dirt road, 48.2 feet (14.7 m) SW of the high water mark, 290 feet
(88.4 m) NE of Bench Mark 9169 D 1976, set into the top of a concrete filled
tile post.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  3 of  4

                                                   PUBLICATION DATE:  06/11/1984
Station ID: 8729169                                SUPERCEDED DATE:   04/21/2003
Name:       SHELL POINT, WEST BAY                             
            FLORIDA
NOAA Chart: 11389                                  Latitude:         30° 12.9' N
USGS Quad:  PANAMA CITY                            Longitude:        85° 44.4' W


                            T I D A L   D A T U M S 


Tidal datums at SHELL POINT, WEST BAY based on:

     LENGTH OF SERIES:      2 MONTHS
     TIME PERIOD:           OCTOBER & NOVEMBER 1976
     TIDAL EPOCH:           1960-1978
     CONTROL TIDE STATION:  8729197 WEST BAY CREEK, WEST BAY


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

     HIGHEST OBSERVED WATER LEVEL (01/14/1977)         =   2.50
     MEAN HIGHER HIGH WATER                     MHHW   =   1.46
     MEAN HIGH WATER                            MHW    =   1.34
     MEAN TIDE LEVEL                            MTL    =   0.75
     MEAN LOW WATER                             MLW    =   0.16
     MEAN LOWER LOW WATER                       MLLW   =   0.00
     LOWEST  OBSERVED WATER LEVEL (11/23/1977)         =  -1.12

North American Vertical Datum (NAVD88)

Bench Mark Elevation Information                In FEET above:

     Stamping or Designation                    MLLW        MHW

     9169 A 1976                                 1.91      0.57
     9169 B 1976                                 2.31      0.97
     9169 C 1976                                 1.12     -0.22
     9169 D 1976                                 1.38      0.04
     WEST BAY PT 2 NO 2                          2.03      0.69


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

                                                   PUBLICATION DATE:  06/11/1984
Station ID: 8729169                                SUPERCEDED DATE:   04/21/2003
Name:       SHELL POINT, WEST BAY                             
            FLORIDA
NOAA Chart: 11389                                  Latitude:         30° 12.9' N
USGS Quad:  PANAMA CITY                            Longitude:        85° 44.4' W


                             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 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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