U.S. DEPARTMENT OF COMMERCE
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National Ocean Service
Datums Page Page 1 of 5
Station ID: 8726976 PUBLICATION DATE: 07/12/2004
Name: BAILEYS BLUFF INSIDE
FL
NOAA Chart: 11409 Latitude: 28° 12.1' N ( 28.20170)
USGS Quad: TARPON SPRINGS Longitude: 82° 46.8' W ( -82.78000)
To reach the tidal bench marks from Tarpon Springs City Hall, proceed north on
U.S. Highway ALT 19 for 3.2 km (2.0 mi) to Anclote Boulevard, then turn left and
proceed west on Anclote Boulevard for 3.2 km (2.0 mi) to its end at Baileys
Bluff Road, then turn right and proceed north and east on Baileys Bluff Road for
3.8 km (2.4 mi) to Gulfview Drive, then proceed north for 0.2 km (0.1 mi) on
Gulfview Drive to East Bayou Road. The bench marks are along Gulfview Drive.
The gage and staff were at house #12 on East Bayou Road.
T I D A L B E N C H M A R K S
PRIMARY BENCH MARK STAMPING: 6976 B 1976
DESIGNATION: 872 6976 B TIDAL
MONUMENTATION: Tidal Station disk VM#: 7677
AGENCY: National Ocean Survey (NOS) IDB PID#: AL7475
SETTING CLASSIFICATION: Copper-clad steel rod OPUS PID:
LATITUDE: 28° 12.2' N ( 28.20330) LONGITUDE: 82° 46.7' W ( -82.77830)
The primary bench mark is a disk located at the SW corner of the intersection of
Gulfview Drive and East Bayou Road, 6.71 m (22.0 ft) south of the centerline of
East Bayou Road, 5.67 m (18.6 ft) west of the centerline of Gulfview Drive, and
0.76 m (2.5 ft) NW of utility pole #14B-6795R with witness sign. The bench mark
is set at 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 2 of 5
Station ID: 8726976 PUBLICATION DATE: 07/12/2004
Name: BAILEYS BLUFF INSIDE
FL
NOAA Chart: 11409 Latitude: 28° 12.1' N ( 28.20170)
USGS Quad: TARPON SPRINGS Longitude: 82° 46.8' W ( -82.78000)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 6976 C 1976
DESIGNATION: 872 6976 C TIDAL
MONUMENTATION: Tidal Station disk VM#: 7678
AGENCY: National Ocean Survey (NOS) IDB PID#: AL7476
SETTING CLASSIFICATION: Copper-clad steel rod OPUS PID:
LATITUDE: 28° 12.4' N ( 28.20670) LONGITUDE: 82° 46.7' W ( -82.77830)
The bench mark is a disk located 0.2 km (0.1 mi) north of bench mark 6976 B
1976, 6.40 m (21.0 ft) east of the centerline of Gulfview Drive, 11.56 m (37.9
ft) east across the road from power pole #2-37407, 1.49 m (4.9 ft) west of a
wood fence, 18.01 m (59.1 ft) south of the south edge of the concrete drive to
house #21 and 65.68 m (215.5 ft) north of the centerline of Sandbay Drive. The
bench mark is set 0.09 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. NOTE: Mark not found in 1988 by US Power
Squadron.
BENCH MARK STAMPING: 6976 D 1976
DESIGNATION: 872 6976 D TIDAL
MONUMENTATION: Tidal Station disk VM#: 7679
AGENCY: National Ocean Survey (NOS) IDB PID#: AL7477
SETTING CLASSIFICATION: Copper-clad steel rod OPUS PID:
LATITUDE: 28° 12.4' N ( 28.20670) LONGITUDE: 82° 46.7' W ( -82.77830)
The bench mark is a disk located 0.3 km (0.2 mi) north of bench mark 6976 C
1976, 9.45 m (31.0 ft) ENE of the centerline of Gulfview Drive, 4.75 m (15.6 ft)
west of the centerline of Pineview Circle, and 0.30 m (1.0 ft) SSW of a utility
pole with witness sign. The bench mark is set at 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 5
Station ID: 8726976 PUBLICATION DATE: 07/12/2004
Name: BAILEYS BLUFF INSIDE
FL
NOAA Chart: 11409 Latitude: 28° 12.1' N ( 28.20170)
USGS Quad: TARPON SPRINGS Longitude: 82° 46.8' W ( -82.78000)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 6976 E 1983
DESIGNATION: 872 6976 E TIDAL
MONUMENTATION: Tidal Station disk VM#: 7680
AGENCY: National Ocean Survey (NOS) IDB PID#: AL7474
SETTING CLASSIFICATION: Concrete monument OPUS PID:
LATITUDE: 29° 12.2' N ( 29.20330) LONGITUDE: 82° 46.7' W ( -82.77830)
The bench mark is a disk set in the top of a concrete monument, 0.2 km (0.1 mi)
south of bench mark 6976 B 1976, 6.89 m (22.6 ft) west of the centerline of
Gulfview Drive, 6 m (20 ft) north of the extended centerline of Baileys Bluff
Road, 3.35 m (11.0 ft) east of the easternmost anchor for the utility pole, 0.73
m (2.4 ft) west of utility pole #2-36457 with witness sign, and at ground level.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 4 of 5
Station ID: 8726976 PUBLICATION DATE: 07/12/2004
Name: BAILEYS BLUFF INSIDE
FL
NOAA Chart: 11409 Latitude: 28° 12.1' N ( 28.20170)
USGS Quad: TARPON SPRINGS Longitude: 82° 46.8' W ( -82.78000)
T I D A L D A T U M S
Tidal datums at BAILEYS BLUFF INSIDE based on:
LENGTH OF SERIES: 1 MONTH
TIME PERIOD: March 1976 - March 1976
TIDAL EPOCH: 1983-2001
CONTROL TIDE STATION: 8726924 ANCLOTE RIVER
Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in METERS:
MEAN HIGHER HIGH WATER MHHW = 0.934
MEAN HIGH WATER MHW = 0.821
North American Vertical Datum NAVD88 = 0.588
MEAN SEA LEVEL MSL = 0.490
MEAN TIDE LEVEL MTL = 0.488
MEAN LOW WATER MLW = 0.155
MEAN LOWER LOW WATER MLLW = 0.000
North American Vertical Datum (NAVD88)
Bench Mark Elevation Information In METERS above:
Stamping or Designation MLLW MHW
6976 B 1976 2.426 1.605
6976 C 1976 4.771 3.950
6976 D 1976 3.371 2.550
6976 E 1983 6.135 5.313
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 5 of 5
Station ID: 8726976 PUBLICATION DATE: 07/12/2004
Name: BAILEYS BLUFF INSIDE
FL
NOAA Chart: 11409 Latitude: 28° 12.1' N ( 28.20170)
USGS Quad: TARPON SPRINGS Longitude: 82° 46.8' W ( -82.78000)
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.