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National Ocean Service
Datums Page Page 1 of 5
Station ID: 8727604 PUBLICATION DATE: 05/12/2004
Name: SHIRED ISLAND
FL
NOAA Chart: 11408 Latitude: 29° 23.9' N ( 29.39830)
USGS Quad: SHIRED ISLAND Longitude: 83° 12.4' W ( -83.20670)
To reach the tidal bench marks from intersection of U.S. Highway 19/98 and
County Road C-351 in Cross City, proceed SW on County Road C-351 for 13.2 km
(8.2 mi) to the junction of County Road C-357 (Shired Island Road), then turn
left and proceed south on County Road C-357 for 17.7 km (11.0 mi) to a paved
road leading west, then turn right and proceed west on the paved road for 0.3 km
(0.2 mi) to the parking area for a state archeological site. The bench marks
are in the area west of the parking area, at the parking area, and along the
highway. The tide gauge and staff were on a pier in Shired Island .
T I D A L B E N C H M A R K S
PRIMARY BENCH MARK STAMPING: 7604 C 1978
DESIGNATION: 872 7604 C TIDAL
MONUMENTATION: Tidal Station disk VM#: 8216
AGENCY: National Ocean Survey (NOS) IDB PID#: AR1647
SETTING CLASSIFICATION: Concrete monument OPUS PID:
LATITUDE: 29° 23.9' N ( 29.39830) LONGITUDE: 83° 12.3' W ( -83.20500)
The primary bench mark is a disk set in the top of a concrete monument at the
east edge of the parking area, 57.91 m (190.0 ft) east of bench mark 7604 B
1978, 27 m (87 ft) south of a concrete sea wall, 8 m (25 ft) east of a palm
tree, 5 m (16 ft) NW of the center of a cattle gap, 1.77 m (5.8 ft) west of a
wire fence, 0.46 m (1.5 ft) west of a witness sign, and 0.06 m (0.2 ft) below
ground level.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 2 of 5
Station ID: 8727604 PUBLICATION DATE: 05/12/2004
Name: SHIRED ISLAND
FL
NOAA Chart: 11408 Latitude: 29° 23.9' N ( 29.39830)
USGS Quad: SHIRED ISLAND Longitude: 83° 12.4' W ( -83.20670)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 7604 A 1978
DESIGNATION: 872 7604 A TIDAL
MONUMENTATION: Tidal Station disk VM#: 8214
AGENCY: National Ocean Survey (NOS) IDB PID#:
SETTING CLASSIFICATION: Concrete post OPUS PID:
LATITUDE: 29° 23.9' N ( 29.39830) LONGITUDE: 83° 12.4' W ( -83.20670)
The bench mark is a disk set in a concrete post, 33 m (108 ft) east of the bait
house, 5 m (15 ft) NE of a large oak tree, 2 m (8 ft) west of the centerline of
the boat ramp, 0.98 m (3.2 ft) SW of the NE corner of the boat ramp, 0.49 m (1.6
ft) south of the north edge of the sea wall, and 0.46 m (1.5 ft) north of the
south edge of the sea wall.
BENCH MARK STAMPING: 7604 B 1978
DESIGNATION: 872 7604 B TIDAL
MONUMENTATION: Tidal Station disk VM#: 8215
AGENCY: National Ocean Survey (NOS) IDB PID#: AR1648
SETTING CLASSIFICATION: Concrete monument OPUS PID:
LATITUDE: 29° 23.9' N ( 29.39830) LONGITUDE: 83° 12.3' W ( -83.20500)
The bench mark is a disk set in the top of a concrete monument at the west edge
of the parking area, 5 m (17 ft) north of the centerline of a dirt road, 0.76 m
(2.5 ft) NW of a palm tree, 0.70 m (2.3 ft) west of a powerline pole with
witness sign attached.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 3 of 5
Station ID: 8727604 PUBLICATION DATE: 05/12/2004
Name: SHIRED ISLAND
FL
NOAA Chart: 11408 Latitude: 29° 23.9' N ( 29.39830)
USGS Quad: SHIRED ISLAND Longitude: 83° 12.4' W ( -83.20670)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 7604 D 1978
DESIGNATION: 872 7604 D TIDAL
MONUMENTATION: Tidal Station disk VM#: 8217
AGENCY: National Ocean Survey (NOS) IDB PID#: AR1646
SETTING CLASSIFICATION: Concrete monument OPUS PID#: AR1646
LATITUDE: 29° 24.0' N ( 29.40000) LONGITUDE: 83° 12.1' W ( -83.20170)
The bench mark is set in the top of a concrete monument, 14 m (45 ft) north of
the centerline of the paved road leading west, 13 m (44 ft) WSW of the
centerline of the highway, 5 m (17 ft) east of a lone palm tree, 1 m (2 ft) east
of a powerline pole with a witness sign attached, and 0.06 m (0.2 ft) below
ground level.
BENCH MARK STAMPING: 41 ATA 11 1951 TT
DESIGNATION: 41 ATA
MONUMENTATION: Bench Mark disk VM#: 8218
AGENCY: US Geological Survey (USGS) IDB PID#: AR1649
SETTING CLASSIFICATION: Concrete monument OPUS PID:
LATITUDE: 29° 23.9' N ( 29.39830) LONGITUDE: 83° 12.5' W ( -83.20830)
The bench mark is a disk set in the top of a concrete monument, 0.5 km (0.3 mi)
west of bench mark 7604 B 1978, 10 m (33 ft) south of the centerline of a track
road, 7 m (22 ft) east of a twin oak tree, 6 m (20 ft) north of the approximate
south shoreline, 3.29 m (10.8 ft) SE of a large cedar tree, 0.30 m (1.0 ft) east
of a witness post, and 0.12 m (0.4 ft) above ground level.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 4 of 5
Station ID: 8727604 PUBLICATION DATE: 05/12/2004
Name: SHIRED ISLAND
FL
NOAA Chart: 11408 Latitude: 29° 23.9' N ( 29.39830)
USGS Quad: SHIRED ISLAND Longitude: 83° 12.4' W ( -83.20670)
T I D A L D A T U M S
Tidal datums at SHIRED ISLAND based on:
LENGTH OF SERIES: 3 MONTHS
TIME PERIOD: September 1978 - November 1978
TIDAL EPOCH: 1983-2001
CONTROL TIDE STATION: 8727520 CEDAR KEY, GULF OF MEXICO
Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in METERS:
MEAN HIGHER HIGH WATER MHHW = 1.059
MEAN HIGH WATER MHW = 0.974
North American Vertical Datum NAVD88 = 0.601
MEAN TIDE LEVEL MTL = 0.567
MEAN SEA LEVEL MSL = 0.565
MEAN LOW WATER MLW = 0.161
MEAN LOWER LOW WATER MLLW = 0.000
North American Vertical Datum (NAVD88)
Bench Mark Elevation Information In METERS above:
Stamping or Designation MLLW MHW
7604 C 1978 2.624 1.650
7604 A 1978 1.829 0.855
7604 B 1978 2.315 1.341
7604 D 1978 2.182 1.208
41 ATA 11 1951 TT 3.731 2.757
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 5 of 5
Station ID: 8727604 PUBLICATION DATE: 05/12/2004
Name: SHIRED ISLAND
FL
NOAA Chart: 11408 Latitude: 29° 23.9' N ( 29.39830)
USGS Quad: SHIRED ISLAND Longitude: 83° 12.4' W ( -83.20670)
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.
Station Location
Published bench mark
Unpublished bench mark
