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.