Bench Mark Sheet for 8729938, TARKLIN BAY

Superseded Epoch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Small blue map location marker Unpublished bench mark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: 8729938                         PUBLICATION DATE:  06/28/2004
Name:       TARKLIN BAY                                       
            FL
NOAA Chart: 11382                           Latitude:   30° 21.0' N (  30.35000)
USGS Quad:  PERDIDO BAY                     Longitude:  87° 24.9' W ( -87.41500)


To reach the tidal bench marks from the intersection of State Road 292 and
County Road 292-A (Gulf Beach Highway) in the community of Perdido Bay, proceed
north on State Road 292 for 2.82 km (1.75 mi) to Merlin Road, then turn left and
proceed NW on Merlin Road for 0.89 km (0.55 mi) to Meadson Road, then turn left
and proceed west and north on Meadson Road for 0.4 km (0.2 mi) to Meadson Way,
then turn left and proceed west and north on Meadson Way for 0.2 km (0.1 mi) to
the Robinson residence.  The bench marks are along Meadson Road and Meadson Way,
and at the Robinson residence.  The tide gage and staff were on a dock behind
the residence.


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


                 PRIMARY BENCH MARK STAMPING:  9938 A 1977
                         DESIGNATION:          872 9938 A TIDAL

MONUMENTATION:           Tidal Station disk                    VM#:        10317
AGENCY:                  National Ocean Survey (NOS)           IDB PID#:  BG3634
SETTING CLASSIFICATION:  Copper-clad steel rod                 OPUS PID:        
LATITUDE:   30° 21.0' N (  30.35000)          LONGITUDE:  87° 24.8' W ( -87.41330)


The primary bench mark is a disk located in the SE corner of the Robinson
property, 30.91 m (101.4 ft) west of the NW corner of a brown brick house, 5 m
(18 ft) west of the centerline of the dirt road, 2 m (6 ft) south of the
Robinson driveway, and 1.04 m (3.4 ft) north of power pole #0810250232.  The
bench mark is set 15 cm (0.5 ft) below ground level, crimped to the top of a
copper-clad steel rod driven 12.2 m (40 ft) to refusal, and encased in a PVC
pipe and concrete kickblock.

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

                                                                                
Station ID: 8729938                         PUBLICATION DATE:  06/28/2004
Name:       TARKLIN BAY                                       
            FL
NOAA Chart: 11382                           Latitude:   30° 21.0' N (  30.35000)
USGS Quad:  PERDIDO BAY                     Longitude:  87° 24.9' W ( -87.41500)


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


                         BENCH MARK STAMPING:  9938 B 1977
                         DESIGNATION:          872 9938 B TIDAL

MONUMENTATION:           Tidal Station disk                    VM#:        10318
AGENCY:                  National Ocean Survey (NOS)           IDB PID#:  BG3633
SETTING CLASSIFICATION:  Copper-clad steel rod                 OPUS PID:        
LATITUDE:   30° 21.0' N (  30.35000)          LONGITUDE:  87° 24.8' W ( -87.41330)


The bench mark is a disk located 0.08 km (0.05 mi) ESE of bench mark 9938 A
1977, 35 m (116 ft) SW of the SW corner of a small white cottage, 5 m (17 ft)
north of centerline of the dirt road leading west, 2.01 m (6.6 ft) south of a 1
m (3 ft) high concrete corner post, and 1.92 m (6.3 ft) east of a power pole
with a witness sign.  The bench mark is set 0.18 m (0.6 ft) below ground level,
crimped to the top of a copper-clad steel rod driven 12.2 m (40 ft) to refusal,
and encased in a PVC pipe and concrete kickblock.



                         BENCH MARK STAMPING:  9938 C 1977
                         DESIGNATION:          872 9938 C TIDAL

MONUMENTATION:           Tidal Station disk                    VM#:        10319
AGENCY:                  National Ocean Survey (NOS)           IDB PID#:  BG3632
SETTING CLASSIFICATION:  Copper-clad steel rod                 OPUS PID:        
LATITUDE:   30° 20.9' N (  30.34830)          LONGITUDE:  87° 24.7' W ( -87.41170)


The bench mark is a disk located 0.08 km (0.05 mi) SE of bench mark 9938 B 1977,
19 m (61 ft) NW of a fire hydrant, 6 m (20 ft) west of the centerline of Meadson
Road leading north, 3 m (11 ft) east of a barbed wire fence line, and 0.15 m
(0.5 ft) east of a witness post.  The bench mark is set 12 cm (0.4 ft) below
ground level, crimped to the top of a copper-clad steel rod driven 12.2 m (40
ft) to refusal, and encased in a PVC pipe and concrete kickblock.

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

                                                                                
Station ID: 8729938                         PUBLICATION DATE:  06/28/2004
Name:       TARKLIN BAY                                       
            FL
NOAA Chart: 11382                           Latitude:   30° 21.0' N (  30.35000)
USGS Quad:  PERDIDO BAY                     Longitude:  87° 24.9' W ( -87.41500)


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


                         BENCH MARK STAMPING:  9938 D 1977
                         DESIGNATION:          872 9938 D TIDAL

MONUMENTATION:           Tidal Station disk                    VM#:        10320
AGENCY:                  National Ocean Survey (NOS)           IDB PID#:  BG3635
SETTING CLASSIFICATION:  Concrete foundation                   OPUS PID:        
LATITUDE:   30° 21.0' N (  30.35000)          LONGITUDE:  87° 24.9' W ( -87.41500)


The bench mark is a disk set in top of the SW corner of the concrete foundation
for the Robinson garage, 78 m (255 ft) NW of bench mark 9938 A 1977, 19 m (61
ft) NNE of the NE corner of the Robinson residence, and 1.13 m (3.7 ft) NW of
the SW corner of the garage.



                         BENCH MARK STAMPING:  9938 E 1977
                         DESIGNATION:          872 9938 E TIDAL

MONUMENTATION:           Tidal Station disk                    VM#:        17231
AGENCY:                  National Ocean Survey (NOS)           IDB PID#:  BG3636
SETTING CLASSIFICATION:  Concrete base for flagpole            OPUS PID:        
LATITUDE:   30° 21.0' N (  30.35000)          LONGITUDE:  87° 24.9' W ( -87.41500)


The bench mark is set flush in a 1 m (3 ft) x 1 m (3 ft) concrete flagpole
foundation located behind Robinsons residence just east of the water's edge, 36
m (117 ft) ENE of the centerline of the Robinson's driveway, 17.53 m (57.5 ft)
WSW of the SW corner of the residence, 11 m (37 ft) east of the water's edge,
and 0.27 m (0.9 ft) SE of the flagpole.

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

                                                                                
Station ID: 8729938                         PUBLICATION DATE:  06/28/2004
Name:       TARKLIN BAY                                       
            FL
NOAA Chart: 11382                           Latitude:   30° 21.0' N (  30.35000)
USGS Quad:  PERDIDO BAY                     Longitude:  87° 24.9' W ( -87.41500)


                            T I D A L   D A T U M S 


Tidal datums at TARKLIN BAY based on:

     LENGTH OF SERIES:      1 MONTH
     TIME PERIOD:           May 1977 - May 1977
     TIDAL EPOCH:           1983-2001
     CONTROL TIDE STATION:  8729962 PERDIDO BAY


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

     MEAN HIGHER HIGH WATER                     MHHW   =  0.193
     MEAN HIGH WATER                            MHW    =  0.191
     MEAN TIDE LEVEL                            MTL    =  0.097
     MEAN SEA LEVEL                             MSL    =  0.091
     MEAN LOW WATER                             MLW    =  0.003
     MEAN LOWER LOW WATER                       MLLW   =  0.000
     North American Vertical Datum              NAVD88 = -0.011

North American Vertical Datum (NAVD88)

Bench Mark Elevation Information                In METERS above:

     Stamping or Designation                    MLLW        MHW

     9938 A 1977                                 1.658    1.467
     9938 B 1977                                 2.145    1.954
     9938 C 1977                                 2.242    2.051
     9938 D 1977                                 1.475    1.284
     9938 E 1977                                 1.246    1.055


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

                                                                                
Station ID: 8729938                         PUBLICATION DATE:  06/28/2004
Name:       TARKLIN BAY                                       
            FL
NOAA Chart: 11382                           Latitude:   30° 21.0' N (  30.35000)
USGS Quad:  PERDIDO BAY                     Longitude:  87° 24.9' W ( -87.41500)


                             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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