U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Datums Page Page 1 of 6
Station ID: 8726853 PUBLICATION DATE: 04/01/2004
Name: INDIAN BLUFF ISLAND
FL
NOAA Chart: 11412 Latitude: 28° 6.2' N ( 28.10330)
USGS Quad: DUNEDIN Longitude: 82° 46.7' W ( -82.77830)
To reach the tidal bench marks from the intersection of U.S. Alt. Route 19 and
Klosterman Road (County Road 79), proceed south on U.S. Alt. Route 19 for 3.1 km
(1.9 mi) to the intersection with Desoto Boulevard, then turn right and proceed
north on Desoto Boulevard for 0.2 km (0.1 mi) to Oceanview Avenue, then turn
left and proceed west on Oceanview Avenue for 0.6 km (0.4 mi) to Phillips Way,
then turn right and proceed north on Phillips Way for 0.2 km (0.1 mi) to house #
117. The bench marks are located near house # 117 and near the intersection of
Oceanview Avenue and Desoto Boulevard. The tide gage and staff were on the wood
dock behind house # 117.
T I D A L B E N C H M A R K S
PRIMARY BENCH MARK STAMPING: NO 1 1975
DESIGNATION: 872 6853 TIDAL 1
MONUMENTATION: Tidal Station disk VM#: 7628
AGENCY: National Ocean Survey (NOS) IDB PID#: AL7485
SETTING CLASSIFICATION: Concrete patio OPUS PID:
LATITUDE: 28° 6.2' N ( 28.10330) LONGITUDE: 82° 46.7' W ( -82.77830)
The primary bench mark is a disk set in the SW corner of the concrete patio of
the house at 117 Phillips Way, 28.19 m (92.5 ft) NE of Bench Mark NO 2 1975, and
0.61 m (2.0 ft) SW of the SE corner of the house.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 2 of 6
Station ID: 8726853 PUBLICATION DATE: 04/01/2004
Name: INDIAN BLUFF ISLAND
FL
NOAA Chart: 11412 Latitude: 28° 6.2' N ( 28.10330)
USGS Quad: DUNEDIN Longitude: 82° 46.7' W ( -82.77830)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: NO 2 1975
DESIGNATION: 872 6853 TIDAL 2
MONUMENTATION: Tidal Station disk VM#: 7629
AGENCY: National Ocean Survey (NOS) IDB PID#: AL7484
SETTING CLASSIFICATION: Copper-clad steel rod OPUS PID:
LATITUDE: 28° 6.2' N ( 28.10330) LONGITUDE: 82° 46.7' W ( -82.77830)
The bench mark is a disk located on the south property line of the house at 117
Phillips Way, 17 m (57 ft) SW of the SW corner of the house, 13.56 m (44.5 ft)
west of the NW corner of house # 115, 6 m (21 ft) ENE of the centerline of
Phillip Way and 0.67 m (2.2 ft) east of utility pole No. 117. The bench mark is
0.06 m (0.2 ft) below ground level, crimped to the top of a copper-clad steel
rod driven an unspecified depth to refusal, and encased in a PVC pipe and
concrete kickblock.
BENCH MARK STAMPING: NO 3 1975
DESIGNATION: 872 6853 TIDAL 3
MONUMENTATION: Tidal Station disk VM#: 7630
AGENCY: National Ocean Survey (NOS) IDB PID#: AL7483
SETTING CLASSIFICATION: Copper-clad steel rod OPUS PID:
LATITUDE: 28° 6.1' N ( 28.10170) LONGITUDE: 82° 46.4' W ( -82.77330)
The bench mark is a disk located 0.2 km (0.1 mi) west of the intersection of
Desoto Boulevard and Oceanview Avenue, 151 m (496 ft) NW of Bench Mark NO 4
1975, 12 m (39 ft) NNW of utility pole #12 A-4460R, 6 m (18 ft) NNE of the NE
corner of the intersection of the railroad track and Ocean View Avenue, 4.72 m
(15.5 ft) north of the centerline of Ocean View Avenue, 2.04 m (6.7 ft) SSW of a
railroad signal light, and 0.76 m (2.5 ft) NW of a stop sign. The bench mark is
0.15 m (0.5 ft) below ground level, crimped to the top of a copper-clad steel
rod driven an unspecified depth 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 6
Station ID: 8726853 PUBLICATION DATE: 04/01/2004
Name: INDIAN BLUFF ISLAND
FL
NOAA Chart: 11412 Latitude: 28° 6.2' N ( 28.10330)
USGS Quad: DUNEDIN Longitude: 82° 46.7' W ( -82.77830)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: NO 4 1975
DESIGNATION: 872 6853 TIDAL 4
MONUMENTATION: Tidal Station disk VM#: 7631
AGENCY: National Ocean Survey (NOS) IDB PID#: AL7482
SETTING CLASSIFICATION: Copper-clad steel rod OPUS PID#: AL7482
LATITUDE: 28° 6.0' N ( 28.10000) LONGITUDE: 82° 46.4' W ( -82.77330)
The bench mark is a disk located at the SW corner of the intersection of Desoto
Boulevard and Oceanview Avenue, 148 m (485 ft) north of Bench Mark INNISBROOK K,
8.69 m (28.5 ft) west of the centerline of Desoto Boulevard, 5.94 m (19.5 ft)
south of the centerline of Ocean View Avenue, and 1.07 m (3.5 ft) north of
utility pole #101-4. The bench mark is 0.30 m (0.3 ft) below ground level,
crimped to the top of a copper-clad steel rod driven an unspecified depth 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 4 of 6
Station ID: 8726853 PUBLICATION DATE: 04/01/2004
Name: INDIAN BLUFF ISLAND
FL
NOAA Chart: 11412 Latitude: 28° 6.2' N ( 28.10330)
USGS Quad: DUNEDIN Longitude: 82° 46.7' W ( -82.77830)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: INNISBROOK K
DESIGNATION: INNISBROOK K
MONUMENTATION: Survey disk VM#: 7632
AGENCY: Pinellas County IDB PID#: AL0243
SETTING CLASSIFICATION: Concrete monument OPUS PID:
LATITUDE: 28° 6.0' N ( 28.10000) LONGITUDE: 82° 46.4' W ( -82.77330)
The bench mark is a disk set into the top of a concrete monument SW of the
intersection of U.S. Alt. Route 19 and Desoto Boulevard, 12 m (40 ft) SW of the
SE corner of the Jersey Bar, 8 m (26 ft) SW of a Jersey Bar sign, 2.23 m (7.3
ft) SE of the SW corner of a brick driveway, 0.76 m (2.5 ft) NE of powerline
pole # 12A-5828R.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 5 of 6
Station ID: 8726853 PUBLICATION DATE: 04/01/2004
Name: INDIAN BLUFF ISLAND
FL
NOAA Chart: 11412 Latitude: 28° 6.2' N ( 28.10330)
USGS Quad: DUNEDIN Longitude: 82° 46.7' W ( -82.77830)
T I D A L D A T U M S
Tidal datums at INDIAN BLUFF ISLAND based on:
LENGTH OF SERIES: 1 MONTH
TIME PERIOD: November 1975 - November 1975
TIDAL EPOCH: 1983-2001
CONTROL TIDE STATION: 8726724 CLEARWATER BEACH, GULF OF MEXICO
Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in METERS:
MEAN HIGHER HIGH WATER MHHW = 0.930
MEAN HIGH WATER MHW = 0.824
North American Vertical Datum NAVD88 = 0.583
MEAN SEA LEVEL MSL = 0.505
MEAN TIDE LEVEL MTL = 0.496
MEAN LOW WATER MLW = 0.168
MEAN LOWER LOW WATER MLLW = 0.000
North American Vertical Datum (NAVD88)
Bench Mark Elevation Information In METERS above:
Stamping or Designation MLLW MHW
NO 1 1975 2.177 1.353
NO 2 1975 1.940 1.116
NO 3 1975 2.414 1.590
NO 4 1975 2.985 2.161
INNISBROOK K 8.556 7.732
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 6 of 6
Station ID: 8726853 PUBLICATION DATE: 04/01/2004
Name: INDIAN BLUFF ISLAND
FL
NOAA Chart: 11412 Latitude: 28° 6.2' N ( 28.10330)
USGS Quad: DUNEDIN Longitude: 82° 46.7' W ( -82.77830)
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.