U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Datums Page Page 1 of 9
Station ID: 8728619 PUBLICATION DATE: 07/22/2024
Name: CAT POINT, APALACHICOLA BAY
FL
NOAA Chart: 11401 Latitude: 29° 43.4' N ( 29.72330)
USGS Quad: APALACHICOLA Longitude: 84° 53.2' W ( -84.88670)
The (TBM) Aquatrak is about 10.2 mi (16.4 km) south-southeast of Beverly, 5.8 mi
(9.3 km) east of Apalachicola, 4.0 mi (6.5 km) southwest of Green Point, in
section 6, township 9 south, range 6 west. To reach the (TBM) Aquatrak from the
post office in Eastpoint, go west on U.S. Highway 98 for 0.5 mi (0.8 km) to the
Intersection of Norvell Street on the right and Island Drive (State Road 300) on
the left, turn left on Island Drive (State Road 300) and go south for 0.7 mi
(1.1 km) to a side road left parallels Island Drive (State Road 300), turn left
on the parallel road and go south for 0.15 mi (0.2 km) to the (TBM) Aquatrak on
the left on a piling of the old ferry landing. Located about 90.0 ft (27.4 m)
off-shore. Benchmarks are located in the vicinity along Island Drive (State Road
300) and U.S. Highway 98.
T I D A L B E N C H M A R K S
PRIMARY BENCH MARK STAMPING: 8619 B 1977
DESIGNATION: 872 8619 B TIDAL
MONUMENTATION: Tidal Station disk VM#: 9848
AGENCY: Florida Department of Natural Resources
(FLDNR) IDB PID#:
SETTING CLASSIFICATION: Copper-clad steel rod OPUS PID#: AS0512
LATITUDE: 29° 43.4' N ( 29.72330) LONGITUDE: 84° 53.3' W ( -84.88833)
The primary bench mark is a disk located 68.58 m (225.0 ft) WSW of bench mark
8619 A 1977, 60.96 m (200.0 ft) WNW of a ramp to the old ferry landing, 16.46 m
(54.0 ft) east of a chain link fence which borders the approach to Bryant Patton
Bridge to St. George Island, 7.83 m (25.7 ft) east of the centerline of a dirt
road, and 0.09 m (0.3 ft) north of a metal witness post. The bench mark is
crimped to the top of a copper-clad steel rod driven 12.19 m (40.0 ft) to
refusal, and encased in a 4-inch PVC pipe and concrete kick-block.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 2 of 9
Station ID: 8728619 PUBLICATION DATE: 07/22/2024
Name: CAT POINT, APALACHICOLA BAY
FL
NOAA Chart: 11401 Latitude: 29° 43.4' N ( 29.72330)
USGS Quad: APALACHICOLA Longitude: 84° 53.2' W ( -84.88670)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 8619 A 1977
DESIGNATION: 872 8619 A TIDAL
MONUMENTATION: Tidal Station disk VM#: 9847
AGENCY: Florida Department of Natural Resources
(FLDNR) IDB PID#:
SETTING CLASSIFICATION: Copper-clad steel rod OPUS PID:
LATITUDE: 29° 43.4' N ( 29.72330) LONGITUDE: 84° 53.2' W ( -84.88670)
The bench mark is a disk located NW of the abandoned ferry pier in a small grove
of trees, 26 m (85 ft) WNW of the approximate high water line on the beach,
11.67 m (38.3 ft) ESE of the SE corner of the foundation of a destroyed
building, 3.57 m (11.7 ft) SE of a two-trunked cedar tree, 2 m (7.0 ft) NNE of a
0.46 m (1.5 ft) diameter live oak tree, and 0.37 m (1.2 ft) WSW of a metal
witness post. The bench mark is set 9 cm (0.3 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 4-inch PVC pipe and concrete kickblock.
BENCH MARK STAMPING: 8619 C 1977
DESIGNATION: 872 8619 C TIDAL
MONUMENTATION: Tidal Station disk VM#: 9849
AGENCY: Florida Department of Natural Resources
(FLDNR) IDB PID#:
SETTING CLASSIFICATION: Concrete island OPUS PID:
LATITUDE: 29° 43.4' N ( 29.72330) LONGITUDE: 84° 53.2' W ( -84.88670)
The bench mark is a disk set in the north end of the concrete island of a toll
booth for Bryant Patton Bridge to St. George Island, 4 m (13 ft) NNW of the NE
corner of the toll booth, 3 m (10 ft) west of the center of the east lane of the
toll booth, and 2.99 m (9.8 ft) east of the center of the west lane of the toll
booth. NOTE: Mark not found in 1997 by US Power Squadron.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 3 of 9
Station ID: 8728619 PUBLICATION DATE: 07/22/2024
Name: CAT POINT, APALACHICOLA BAY
FL
NOAA Chart: 11401 Latitude: 29° 43.4' N ( 29.72330)
USGS Quad: APALACHICOLA Longitude: 84° 53.2' W ( -84.88670)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 8619 D 1977
DESIGNATION: 872 8619 D TIDAL
MONUMENTATION: Tidal Station disk VM#: 9850
AGENCY: Florida Department of Natural Resources
(FLDNR) IDB PID#:
SETTING CLASSIFICATION: Concrete monument OPUS PID:
LATITUDE: 29° 43.6' N ( 29.72670) LONGITUDE: 84° 53.3' W ( -84.88830)
The bench mark is a disk set in a concrete monument north of the toll booth for
Bryant Patton Bridge to St. George Island, 36 m (118 ft) NW of and across the
road from a telephone pole, 14.17 m (46.5 ft) south of power pole R-46, 12.19 m
(40.0 ft) west of the centerline of S-65, and 0.64 m (2.1 ft) east of a metal
witness post, and level with the ground.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 4 of 9
Station ID: 8728619 PUBLICATION DATE: 07/22/2024
Name: CAT POINT, APALACHICOLA BAY
FL
NOAA Chart: 11401 Latitude: 29° 43.4' N ( 29.72330)
USGS Quad: APALACHICOLA Longitude: 84° 53.2' W ( -84.88670)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: C 689 2007
DESIGNATION: C 689
MONUMENTATION: Flange-encased Rod VM#: 19020
AGENCY: National Geodetic Survey (NGS) IDB PID#:
SETTING CLASSIFICATION: Stainless steel rod in sleeve OPUS PID#: DM4876
LATITUDE: 29° 44.7' N ( 29.74500) LONGITUDE: 84° 51.8' W ( -84.86333)
The bench mark is a flange encased rod located 18.90 m (62.0 ft) north of the
centerline of U.S. Highway 98, 12.50 m (41.0 ft) NE of a fire hydrant, 4.21 m
(13.8 ft) east of the centerline of 7th Street, 0.58 km (1.9 ft) SE of an
information sign (WATCH FOR CHILDREN), and 0.55 m (1.8 ft) SE of a carsonite
witness post. The datum point is recessed 0.12 m (0.4 ft) below the level of
the NGS logo cap, being the top of a stainless steel rod in a sleeve, driven to
refusal at a depth of 17.37 m (57.0 ft) with a NGS logo cap flush with the
ground and 0.30 m (1.0 ft) below the level of the highway, and encased in a
5-inch NGS logo cap containing a magnet.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 5 of 9
Station ID: 8728619 PUBLICATION DATE: 07/22/2024
Name: CAT POINT, APALACHICOLA BAY
FL
NOAA Chart: 11401 Latitude: 29° 43.4' N ( 29.72330)
USGS Quad: APALACHICOLA Longitude: 84° 53.2' W ( -84.88670)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: B 689 2007
DESIGNATION: B 689
MONUMENTATION: Flange-encased Rod VM#: 19021
AGENCY: National Geodetic Survey (NGS) IDB PID#:
SETTING CLASSIFICATION: Stainless steel rod in sleeve OPUS PID:
LATITUDE: 29° 44.3' N ( 29.73833) LONGITUDE: 84° 52.5' W ( -84.87500)
The bench mark is a flange-encased rod located about 146.30 m (480.0 ft) SW of
the centerline of 1st Street, about 87.48 m (287.0 ft) NE of the centerline of
the school road, 12.50 m (41.0 ft) north of the centerline of U.S. Highway 98,
3.14 m (10.3 ft) SE of the SE corner of a vacant metal building, 0.30 m (1.0 ft)
north of the north edge of a concrete sidewalk, and 0.30 m (1.0 ft) south of a
carsonite witness post. The datum point is recessed 0.06 m (0.2 ft) below the
level of the logo cap, being the top of a stainless steel rod in a sleeve,
driven to refusal at a depth of 19.20 m (63.0 ft) flush with the ground and 0.30
m (1.0 ft) below the level of the U.S. Highway 98, and encased in a 5-inch NGS
logo cap (containing a magnet) flush with the ground.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 6 of 9
Station ID: 8728619 PUBLICATION DATE: 07/22/2024
Name: CAT POINT, APALACHICOLA BAY
FL
NOAA Chart: 11401 Latitude: 29° 43.4' N ( 29.72330)
USGS Quad: APALACHICOLA Longitude: 84° 53.2' W ( -84.88670)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 8619 E
DESIGNATION: 872 8619 E
MONUMENTATION: Survey disk VM#: 19023
AGENCY: Florida Dept. of Transportation (FLDOT)IDB PID#:
SETTING CLASSIFICATION: Concrete Guardrail OPUS PID:
LATITUDE: 29° 43.4' N ( 29.72291) LONGITUDE: 84° 53.3' W ( -84.88786)
The bench mark is a disk set flush in the top of the guardrail above the
abutment at the NE end of the bridge, 7.04 m (23.1 ft) east of the centerline of
the highway, 6.37 m (20.9 ft) south of the end of the asphalt pavement
approaching the bridge, 1.83 m (6.0 ft) east of bench mark 8619 F, 0.85 m (2.8
ft) above the level of the State Highway 300, and 0.18 m (0.6 ft) south of the
north end of the second guardrail section south of the end of the asphalt
pavement approaching the bridge.
BENCH MARK STAMPING: 8619 F
DESIGNATION: 872 8619 F
MONUMENTATION: Survey disk VM#: 19024
AGENCY: Florida Dept. of Transportation (FLDOT)IDB PID#:
SETTING CLASSIFICATION: Concrete Guardrail OPUS PID:
LATITUDE: 29° 43.4' N ( 29.72292) LONGITUDE: 84° 53.3' W ( -84.88810)
The bench mark is a disk set flush in the top of the guardrail above the
abutment at the NW end of the bridge, 14.02 m (46.0 ft) west of bench mark 8619
E, 6.95 m (22.8 ft) west of the centerline of the highway, 6.40 m (21.0 ft)
south of the end of the asphalt pavement approaching the bridge, 0.85 m (2.8 ft)
above the level of the State Highway 300, and 0.18 m (0.6 ft) south of the north
end of the second guardrail section south of the end of the asphalt pavement
approaching the bridge.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 7 of 9
Station ID: 8728619 PUBLICATION DATE: 07/22/2024
Name: CAT POINT, APALACHICOLA BAY
FL
NOAA Chart: 11401 Latitude: 29° 43.4' N ( 29.72330)
USGS Quad: APALACHICOLA Longitude: 84° 53.2' W ( -84.88670)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 8619 G 2018
DESIGNATION: 872 8619 G
MONUMENTATION: Flange-encased Rod VM#: 24316
AGENCY: National Geodetic Survey (NGS) IDB PID#:
SETTING CLASSIFICATION: Stainless steel rod OPUS PID#: DR3132
LATITUDE: 29° 44.2' N ( 29.73589) LONGITUDE: 84° 53.5' W ( -84.89203)
The bench mark located 16.80 m (55.0 ft) west of the extended centerline of the
west entrance to (Badcock and more) furniture store located at U.S. mail address
197 U.S. highway 98, 14.80 m (48.5 ft) south of the approximate centerline of
U.S. highway 98, 13.60 m (44.5 ft) east of the west chain link fence corner,
1.25 m (4.1 ft) north of a chain link fence and 1.20 m (4.1 ft) north of a
carsonite witness post. The bench mark is a stainless steel rod driven to
refusal at a depth of 17.2 m (56.5 ft), recessed 0.09m (0.3 ft) below the level
of the ground and 0.5 m (1.5 ft) below the level of U.S. highway 98, the datum
point is recessed 0.15m (0.5 ft) below the level of the (NGS) logo cap.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 8 of 9
Station ID: 8728619 PUBLICATION DATE: 07/22/2024
Name: CAT POINT, APALACHICOLA BAY
FL
NOAA Chart: 11401 Latitude: 29° 43.4' N ( 29.72330)
USGS Quad: APALACHICOLA Longitude: 84° 53.2' W ( -84.88670)
T I D A L D A T U M S
Tidal datums at CAT POINT, APALACHICOLA BAY based on:
LENGTH OF SERIES: 6 MONTHS
TIME PERIOD: March 2021 - August 2021
TIDAL EPOCH: 1983-2001
CONTROL TIDE STATION: 8728690 APALACHICOLA, APALACHICOLA RIVER
Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in METERS:
MEAN HIGHER HIGH WATER MHHW = 0.613
MEAN HIGH WATER MHW = 0.569
MEAN TIDE LEVEL MTL = 0.359
MEAN SEA LEVEL MSL = 0.348
North American Vertical Datum NAVD88 = 0.343
MEAN LOW WATER MLW = 0.150
MEAN LOWER LOW WATER MLLW = 0.000
North American Vertical Datum (NAVD88)
Bench Mark Elevation Information In METERS above:
Stamping or Designation MLLW MHW
8619 B 1977 2.105 1.536
8619 A 1977 1.389 0.820
8619 C 1977 2.085 1.516
8619 D 1977 1.174 0.605
C 689 2007 3.024 2.455
B 689 2007 2.166 1.597
8619 E 7.957 7.388
8619 F 7.112 6.543
8619 G 2018 5.256 4.687
Foot Notes:
Bench marks B 689 2007 and C 689 2007 are based on one differential leveling
connection and do not meet the quality control standards of the NOS. Therefore,
caution should be used when deriving elevations for these marks.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 9 of 9
Station ID: 8728619 PUBLICATION DATE: 07/22/2024
Name: CAT POINT, APALACHICOLA BAY
FL
NOAA Chart: 11401 Latitude: 29° 43.4' N ( 29.72330)
USGS Quad: APALACHICOLA Longitude: 84° 53.2' W ( -84.88670)
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.