U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Datums Page Page 1 of 5
PUBLICATION DATE: 06/11/1986
Station ID: 8728669 SUPERCEDED DATE: 04/21/2003
Name: SIKES CUT, ST. GEORGE ISLAND
FLORIDA
NOAA Chart: 11401 Latitude: 29° 36.8' N
USGS Quad: NEW INLET Longitude: 84° 57.6' W
To reach the tidal bench marks from the public marina in Apalachicola, proceed
by boat south on the main ship channel to can bouy C 1, then on a heading of 160
from the bouy for 3.0 miles (4.8 km) to Sikes Cut. The bench marks are located
on both sides of the cut. The tide gage and staff were located on a three-pile
platform on the west side of the cut 150 feet (46 m) north of the north end of
the rip-rap.
T I D A L B E N C H M A R K S
PRIMARY BENCH MARK STAMPING: 8669 G 1983
MONUMENTATION: Survey Disk VM#: 9860
AGENCY: PID#: AS0555
SETTING CLASSIFICATION: Stainless Steel Rod
The bench mark is on top of the grass-covered flat on the west side of Sikes
Cut, 222 feet (68 m) NW of Bench Mark 8669 F 1983, 69 feet (21 m) west of the
embankment of dredge spoil, and 2.2 feet (0.7 m) east of a witness post. The
bench mark is at ground level, crimped to a stainless steel rod driven 28 feet
(9 m) to substantial resistance, encased in a 4-inch PVC pipe and concrete
kickblock.
BENCH MARK STAMPING: 290844 AA2 1975
MONUMENTATION: Survey Disk VM#: 9858
AGENCY: PID#: AS0410
SETTING CLASSIFICATION: Copper-clad Steel Rod
The bench mark is located in the center of a grove of palm trees, along the
treeline on the west side of the grassy area on the west side of Sikes Cut, 421
feet (128 m) west of Bench Mark 4980 A17 along the treeline, 12.0 feet (3.7 m)
ENE of a 1.5-foot (0.5 m) diameter pine tree, and 1.5 feet (0.5 m) east of a
metal witness post. The bench mark is crimped to a copper-clad steel rod driven
32 feet (10 m) to refusal, encased in a 4-inch PVC pipe and concrete kickblock.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 2 of 5
PUBLICATION DATE: 06/11/1986
Station ID: 8728669 SUPERCEDED DATE: 04/21/2003
Name: SIKES CUT, ST. GEORGE ISLAND
FLORIDA
NOAA Chart: 11401 Latitude: 29° 36.8' N
USGS Quad: NEW INLET Longitude: 84° 57.6' W
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 8669 F 1983
MONUMENTATION: Survey Disk VM#: 9859
AGENCY: PID:
SETTING CLASSIFICATION: Stainless Steel Rod
The bench mark is on the west side of dune line on top of a grass-covered flat,
near the north end of rip-rap on the west side of Sikes Cut, 317 feet (97 m) ENE
of Bench Mark 49 80 A17, 222 feet (68 m) SE of Bench Mark 8669 G 1983 and 2.0
feet (0.6 m) east of a witness post. The bench mark is at ground level, crimped
to a stainless steel rod driven 32 feet (10 m) to substantial resistance,
encased in a 4-inch PVC pipe and concrete kickblock.
BENCH MARK STAMPING: 8669 H 1983
MONUMENTATION: Survey Disk VM#: 9861
AGENCY: PID#: AS0554
SETTING CLASSIFICATION: Stainless Steel Rod
The bench mark is on top of the grassy flat on the west side of Sikes Cut, 196
feet (60 m) NW of Bench Mark 8669 G 1983, 158 feet (48 m) NE of a lone cabbage
palm, 52 feet (16 m) west of an embankment starting the dredge spoil, and 1.8
feet (0.5 m) east of a witness post. The bench mark is at ground level, crimped
to a stainless steel rod driven 32 feet (10 m) to substantial resistance,
encased in a 4-inch PVC pipe and concrete kickblock.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 3 of 5
PUBLICATION DATE: 06/11/1986
Station ID: 8728669 SUPERCEDED DATE: 04/21/2003
Name: SIKES CUT, ST. GEORGE ISLAND
FLORIDA
NOAA Chart: 11401 Latitude: 29° 36.8' N
USGS Quad: NEW INLET Longitude: 84° 57.6' W
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 4980 A17
MONUMENTATION: Survey Disk VM#: 9862
AGENCY: PID#: AS0553
SETTING CLASSIFICATION: Concrete Monument
The bench mark is set in concrete on top of the grass-covered flat west of Sikes
Cut, 421 feet (128 m) east of Bench Mark 290844 AA2 1975 along the treeline, 196
feet (60 m) NW of a vegetation line, 5.5 feet (1.7 m) south of a witness post,
and 0.7 foot (0.2 m) below ground level.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 4 of 5
PUBLICATION DATE: 06/11/1986
Station ID: 8728669 SUPERCEDED DATE: 04/21/2003
Name: SIKES CUT, ST. GEORGE ISLAND
FLORIDA
NOAA Chart: 11401 Latitude: 29° 36.8' N
USGS Quad: NEW INLET Longitude: 84° 57.6' W
T I D A L D A T U M S
Tidal datums at SIKES CUT, ST. GEORGE ISLAND based on:
LENGTH OF SERIES: 1 MONTH
TIME PERIOD: MARCH 1984
TIDAL EPOCH: 1960-1978
CONTROL TIDE STATION: 8728690 APALACHICOLA
Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in FEET:
HIGHEST OBSERVED WATER LEVEL (03/20/1984) = 3.61
MEAN HIGHER HIGH WATER MHHW = 2.02
MEAN HIGH WATER MHW = 1.77
MEAN TIDE LEVEL MTL = 1.15
MEAN LOW WATER MLW = 0.54
MEAN LOWER LOW WATER MLLW = 0.00
LOWEST OBSERVED WATER LEVEL (02/29/1984) = -1.82
North American Vertical Datum (NAVD88)
Bench Mark Elevation Information In FEET above:
Stamping or Designation MLLW MHW
8669 G 1983 15.78 14.01
290844 AA2 1975 5.99 4.22
8669 F 1983 14.08 12.31
8669 H 1983 15.44 13.67
4980 A17 15.36 13.59
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 5 of 5
PUBLICATION DATE: 06/11/1986
Station ID: 8728669 SUPERCEDED DATE: 04/21/2003
Name: SIKES CUT, ST. GEORGE ISLAND
FLORIDA
NOAA Chart: 11401 Latitude: 29° 36.8' N
USGS Quad: NEW INLET Longitude: 84° 57.6' 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.