U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Datums Page Page 1 of 4
PUBLICATION DATE: 01/12/1988
Station ID: 8728262 SUPERCEDED DATE: 04/21/2003
Name: OCHLOCKONEE BAY
FLORIDA
NOAA Chart: 11405 Latitude: 29° 58.6' N
USGS Quad: LIGHTHOUSE POINT Longitude: 84° 22.5' W
To reach the tidal bench marks from the Post Office in Panacea, proceed 3.7
miles (6.0 km) south on U.S. Highway 98 to County Road C-372, then east on
County Road C-372 for 0.35 mile (0.56 km) to the Harvey Hill residence. The
bench marks are located along County Road C-372. The tide gage and staff were
located on Mr. Hills pier.
T I D A L B E N C H M A R K S
PRIMARY BENCH MARK STAMPING: 290841 AC1 1975
MONUMENTATION: Survey disk VM#: 9790
AGENCY: PID#: AS0482
SETTING CLASSIFICATION: Copper-clad Steel Rod
The bench mark is 0.35 mile (0.56 km) east of the intersection of U.S. Highway
98 and County Road C-372, 83.0 feet (25.3 m) NW of the centerline of a dirt road
that intersects County Road C-372, 24.7 feet (7.5 m) SW of the centerline of the
county road, 16.3 feet (5.0 m) ENE of utility pole #59V2190R, and 2 feet (1 m)
NE of a witness post. The bench mark is level with the ground, crimped to the
top of a copper-clad steel rod driven 48 feet (15 m), and encased in a PVC pipe
and concrete kickblock.
BENCH MARK STAMPING: 290841 AC2 1975
MONUMENTATION: Survey Disk VM#: 9791
AGENCY: PID#: AS0481
SETTING CLASSIFICATION: Copper-clad Steel Rod
The bench mark is 172.5 feet (52.6 m) WNW of Bench Mark 290841 AC1 1975, 86.8
feet (26.5 m) south of the eastern gate post to a private drive leading north,
28.3 feet (8.6 m) SW of the centerline of the county road, 24.0 feet (7.3 m) SE
of the centerline of a private drive leading south, 9.7 feet (3.0 m) ESE of
utility pole #59V-980, and 1.3 feet (0.4 m) NE of a witness post. The bench
mark is 0.3 foot (0.1 m) above ground, crimped to the top of a copper-clad steel
rod driven 48 feet (15 m) 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 4
PUBLICATION DATE: 01/12/1988
Station ID: 8728262 SUPERCEDED DATE: 04/21/2003
Name: OCHLOCKONEE BAY
FLORIDA
NOAA Chart: 11405 Latitude: 29° 58.6' N
USGS Quad: LIGHTHOUSE POINT Longitude: 84° 22.5' W
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 290841 AC4 1975
MONUMENTATION: Survey Disk VM#: 9792
AGENCY: PID#: AS0478
SETTING CLASSIFICATION: Concrete Sea Wall
The bench mark is set flush in the top of a concrete sea wall on the NE corner
of the County Road C-372 bridge over a tidal creek 0.25 mile (0.40 km) east of
U.S. Highway 98, 26.0 feet (7.9 m) north of the centerline of the county road,
16.8 feet (5.1 m) WNW of the NE bridge abutment, 12.2 feet (3.7 m) NE of the
most northeastern piling under the bridge, and 1.5 feet (0.5 m) east of the west
sea wall edge.
BENCH MARK STAMPING: 290841 AC5 1975
MONUMENTATION: Survey disk VM#: 9793
AGENCY: PID#: AS0479
SETTING CLASSIFICATION: Concrete Sea Wall
The bench mark is set flush in the top of a concrete sea wall on the SE corner
of the County Road C-372 bridge over a tidal creek 0.25 mile (0.40 km) east of
U.S. Highway 98, 45.7 feet (13.9 m) south of Bench Mark 290841 AC4 1975, 19.7
feet (6.0 m) south of the centerline of county road, 15.4 feet (4.7 m) WNW of
the SE tidal bridge abutment, 6.1 feet (1.9 m) SE of the most southeastern
piling under the tidal creek bridge, and 0.8 foot (0.2 m) east of the west sea
wall edge.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 3 of 4
PUBLICATION DATE: 01/12/1988
Station ID: 8728262 SUPERCEDED DATE: 04/21/2003
Name: OCHLOCKONEE BAY
FLORIDA
NOAA Chart: 11405 Latitude: 29° 58.6' N
USGS Quad: LIGHTHOUSE POINT Longitude: 84° 22.5' W
T I D A L D A T U M S
Tidal datums at OCHLOCKONEE BAY based on:
LENGTH OF SERIES: 3 MONTHS
TIME PERIOD: DECEMBER 1975-MARCH 1976
TIDAL EPOCH: 1960-1978
CONTROL TIDE STATION: 8728229 SHELL POINT
Elevations of tidal datums referred to Mean High Water (MHW), in FEET:
HIGHEST OBSERVED WATER LEVEL (12/25/1975) = 2.54
MEAN HIGHER HIGH WATER MHHW = 0.24
MEAN HIGH WATER MHW = 0.00
North American Vertical Datum (NAVD88)
Bench Mark Elevation Information In FEET above:
Stamping or Designation MHW
290841 AC1 1975 4.34
290841 AC2 1975 3.75
290841 AC4 1975 3.92
290841 AC5 1975 3.92
Foot Notes:
The datums were computed by the NOS Direct Method due to flat low waters.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 4 of 4
PUBLICATION DATE: 01/12/1988
Station ID: 8728262 SUPERCEDED DATE: 04/21/2003
Name: OCHLOCKONEE BAY
FLORIDA
NOAA Chart: 11405 Latitude: 29° 58.6' N
USGS Quad: LIGHTHOUSE POINT Longitude: 84° 22.5' 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.