U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Datums Page Page 1 of 5
PUBLICATION DATE: 12/15/1987
Station ID: 8726853 SUPERCEDED DATE: 04/21/2003
Name: INDIAN BLUFF ISLAND, BOGGY BAYOU
FLORIDA
NOAA Chart: 11412 Latitude: 28° 6.2' N
USGS Quad: DUNEDIN Longitude: 82° 46.7' W
To reach the tidal bench marks from the intersection of U.S. Highway 19 (ALT)
and Klosterman Road (CR 79), proceed south on U.S. Highway 19 (ALT) for 1.9
miles (3.1 km) to the intersection with Desoto Boulevard, continue northerly on
Desoto Boulevard to the intersection with Ocean View Avenue, then west on Ocean
View Avenue to Phillip Way, then turn right on Phillip Way to house No. 177.
The bench marks are located near house No. 117 and near the intersection of
Ocean View Avenue and DeSoto Boulevard, and the tide gage and staff were on the
wood dock behind house No. 177.
T I D A L B E N C H M A R K S
PRIMARY BENCH MARK STAMPING: NO 1 1975
MONUMENTATION: Survey Disk VM#: 7628
AGENCY: PID#: AL7485
SETTING CLASSIFICATION: Concrete Pad
The bench mark is on the east side of Phillip Way set flush in a concrete pad at
house No. 117, 92.5 feet (28.2 m) NE of Bench Mark NO 2 1975, and 2.0 feet (0.6
m) SW of the NE corner of house.
BENCH MARK STAMPING: NO 2 1975
MONUMENTATION: Survey Disk VM#: 7629
AGENCY: PID#: AL7484
SETTING CLASSIFICATION: Copper-clad Steel Rod
The bench mark is on the south property line and 57 feet (17 m) SW of the SE
corner of house No. 117, 44.5 feet (13.6 m) WNW of the NE corner of house No.
115, 21 feet (6 m) east of the centerline of Phillip Way and 2.2 feet (0.7 m)
east of utility pole No. 117. The bench mark is at ground level, crimped to a
copper-clad steel rod driven 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
PUBLICATION DATE: 12/15/1987
Station ID: 8726853 SUPERCEDED DATE: 04/21/2003
Name: INDIAN BLUFF ISLAND, BOGGY BAYOU
FLORIDA
NOAA Chart: 11412 Latitude: 28° 6.2' N
USGS Quad: DUNEDIN Longitude: 82° 46.7' W
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: NO 3 1975
MONUMENTATION: Survey Disk VM#: 7630
AGENCY: PID#: AL7483
SETTING CLASSIFICATION: Copper-clad Steel Rod
The bench mark is near the intersection of Desoto Boulevard and Ocean View
Avenue, 496 feet (151 m) NW of Bench Mark NO 4 1975, 39 feet (12 m) NNW of
utility pole No. 12 A-4460 R, 18 feet (6 m) NNE of the NE corner of the
intersection of the railroad track and Ocean View Avenue, 15.5 feet (4.7 m) NNW
of the centerline of Ocean View Avenue, and 2.5 feet (0.8 m) NW of a stop sign.
The bench mark is 0.5 foot (0.2 m) below ground level, crimped to a copper-clad
steel rod driven to refusal and encased in a PVC pipe and concrete kickblock.
BENCH MARK STAMPING: NO 4 1975
MONUMENTATION: Survey Disk VM#: 7631
AGENCY: PID#: AL7482
SETTING CLASSIFICATION: Copper-clad Steel Rod
The bench mark is at the SW corner of the intersection of Desoto Boulevard and
Ocean View Avenue, 485 feet ( 148 m) north of Bench Mark INNISBROOK K, 28.5 feet
(8.7 m) west of the centerline of Desoto Boulevard, 19.5 feet (5.9 m) south of
Ocean View Avenue and 3.5 feet (1.1 m) north of utility pole No. 101-4. The
bench mark is 0.3 foot (0.1 m) below ground level, crimped to a copper-clad
steel rod driven 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
PUBLICATION DATE: 12/15/1987
Station ID: 8726853 SUPERCEDED DATE: 04/21/2003
Name: INDIAN BLUFF ISLAND, BOGGY BAYOU
FLORIDA
NOAA Chart: 11412 Latitude: 28° 6.2' N
USGS Quad: DUNEDIN Longitude: 82° 46.7' W
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: INNISBROOK K
MONUMENTATION: Survey Disk VM#: 7632
AGENCY: PID#: AL0243
SETTING CLASSIFICATION: Concrete Post
The bench mark is set into the top of a concrete post at ground level, SW of the
intersection of U.S. Highway 19 (ALT) and Desoto Boulevard, 40 feet (12 m) SW of
the SE corner of the Jersey Bar, 26 feet (8 m) SW of a Jersey Bar sign, 7.3 feet
(2.2 m) SE of the SW corner of a brick driveway and 2.5 feet (0.8 m) NE of
utility pole No. 12A-5828R.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 4 of 5
PUBLICATION DATE: 12/15/1987
Station ID: 8726853 SUPERCEDED DATE: 04/21/2003
Name: INDIAN BLUFF ISLAND, BOGGY BAYOU
FLORIDA
NOAA Chart: 11412 Latitude: 28° 6.2' N
USGS Quad: DUNEDIN Longitude: 82° 46.7' W
T I D A L D A T U M S
Tidal datums at INDIAN BLUFF ISLAND, BOGGY BAYOU based on:
LENGTH OF SERIES: 1 MONTH
TIME PERIOD: NOVEMBER 1975
TIDAL EPOCH: 1960-1978
CONTROL TIDE STATION: 8726761 DUNEDIN
Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in FEET:
HIGHEST OBSERVED WATER LEVEL (11/07/1975) = 3.90
MEAN HIGHER HIGH WATER MHHW = 3.02
MEAN HIGH WATER MHW = 2.68
MEAN TIDE LEVEL MTL = 1.62
MEAN LOW WATER MLW = 0.56
MEAN LOWER LOW WATER MLLW = 0.00
LOWEST OBSERVED WATER LEVEL (12/03/1975) = -0.87
North American Vertical Datum (NAVD88)
Bench Mark Elevation Information In FEET above:
Stamping or Designation MLLW MHW
NO 1 1975 7.29 4.61
NO 2 1975 6.51 3.83
NO 3 1975 8.07 5.39
NO 4 1975 9.94 7.26
INNISBROOK K 28.22 25.54
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 5 of 5
PUBLICATION DATE: 12/15/1987
Station ID: 8726853 SUPERCEDED DATE: 04/21/2003
Name: INDIAN BLUFF ISLAND, BOGGY BAYOU
FLORIDA
NOAA Chart: 11412 Latitude: 28° 6.2' N
USGS Quad: DUNEDIN Longitude: 82° 46.7' 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.