U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Datums Page Page 1 of 5
PUBLICATION DATE: 08/22/2000
Station ID: 8726537 SUPERCEDED DATE: 04/21/2003
Name: APOLLO BEACH, HILLSBOROUGH BAY
FLORIDA
NOAA Chart: 11413 Latitude: 27° 47.2' N
USGS Quad: Gibsonton Longitude: 82° 25.6' W
To reach the tidal bench marks from the intersection of U.S. Highway 41 and
Apollo Boulevard, proceed west on Apollo Boulevard for 3.7 km (2.3 mi) to the
T-road junction of Surfside Boulevard and the Holiday Inn. The bench marks are
around the Holiday Inn's parking lot and along the eastbound lane of Apollo
Boulevard. The gage and staff were located on the Tiki Cay Condominium dock.
T I D A L B E N C H M A R K S
PRIMARY BENCH MARK STAMPING: 6537 A 1976
DESIGNATION: 872 6537 A TIDAL
MONUMENTATION: Tidal Station disk VM#: 11499
AGENCY: National Ocean Survey (NOS) PID#: AG6385
SETTING CLASSIFICATION: Concrete sidewalk
The primary bench mark is a disk set in a concrete sidewalk at the NW edge of a
breezeway near the NW corner of Holiday Inn, 11.37 m (37.3 ft) SE of the sea
wall, 1.31 m (4.3 ft) SW of the parking lot curb, and 0.21 m (0.7 ft) SE of the
motel.
BENCH MARK STAMPING: 6537 B 1976
DESIGNATION: 872 6537 B TIDAL
MONUMENTATION: Tidal Station disk VM#: 11500
AGENCY: National Ocean Survey (NOS) PID#: AG6386
SETTING CLASSIFICATION: Concrete light pole base
The bench mark is a disk set in the NE corner of the concrete base for a light
pole, 80 m (261 ft) NE of bench mark 6537 C 1976, 23.10 m (75.8 ft) SE of the NE
corner of the Holiday Inn, 11.52 m (37.8 ft) NW of the centerline of Surfside
Boulevard, and 0.61 m (2.0 ft) above the pavement.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 2 of 5
PUBLICATION DATE: 08/22/2000
Station ID: 8726537 SUPERCEDED DATE: 04/21/2003
Name: APOLLO BEACH, HILLSBOROUGH BAY
FLORIDA
NOAA Chart: 11413 Latitude: 27° 47.2' N
USGS Quad: Gibsonton Longitude: 82° 25.6' W
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 6537 C 1976
DESIGNATION: 872 6537 C TIDAL
MONUMENTATION: Tidal Station disk VM#: 11501
AGENCY: National Ocean Survey (NOS) PID#: AG6387
SETTING CLASSIFICATION: Concrete light pole base
The bench mark is a disk set in the SE corner of the concrete base of a light
pole, 19.72 m (64.7 ft) SE of the SE corner of the Holiday Inn, 11.09 m (36.4
ft) NW of the centerline of Surfside Boulevard, and 0.61 m (2.0 ft) above the
pavement.
BENCH MARK STAMPING: 6537 E 1976
DESIGNATION: 872 6537 E TIDAL
MONUMENTATION: Tidal Station disk VM#: 11502
AGENCY: National Ocean Survey (NOS) PID#: AG6388
SETTING CLASSIFICATION: Copper-Clad steel rod
The bench mark is a disk located at the NW corner of the westernmost entrance to
the Holiday Inn parking lot, 37.85 m (124.2 ft) SW of bench mark 6537 C 1976,
13.62 m (44.7 ft) south of the SE corner of the Holiday Inn, 5.97 m (19.6 ft) NW
of the centerline of Surfside Boulevard, and 0.27 m (0.9 ft) south of a witness
post. The bench mark is crimped to a copper-clad steel rod driven an unspecified
depth to refusal, and encased in a PVC pipe with concrete kickblock.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 3 of 5
PUBLICATION DATE: 08/22/2000
Station ID: 8726537 SUPERCEDED DATE: 04/21/2003
Name: APOLLO BEACH, HILLSBOROUGH BAY
FLORIDA
NOAA Chart: 11413 Latitude: 27° 47.2' N
USGS Quad: Gibsonton Longitude: 82° 25.6' W
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 6537 G 1990
DESIGNATION: 872 6537 G TIDAL
MONUMENTATION: Flange-encased Rod VM#: 11503
AGENCY: National Ocean Service (NOS) PID#: AG9409
SETTING CLASSIFICATION: Stainless steel rod
The bench mark is the top of a stainless steel rod located along the west side
of Apollo Boulevard, 0.3 km (0.2 mi) SE of bench mark 6537 E 1976, 21.28 m (69.8
ft) NW of the NW corner of a concrete block building, 9.63 m (31.6 ft) SW of the
centerline of Apollo Boulevard, and 1.16 m (3.8 ft) south of a power pole. The
bench mark is a flanged encased stainless steel rod driven 20.1 m (66 ft) to
refusal, and encased in a hinged-top access cover attached to a PVC pipe with
concrete kickblock.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 4 of 5
PUBLICATION DATE: 08/22/2000
Station ID: 8726537 SUPERCEDED DATE: 04/21/2003
Name: APOLLO BEACH, HILLSBOROUGH BAY
FLORIDA
NOAA Chart: 11413 Latitude: 27° 47.2' N
USGS Quad: Gibsonton Longitude: 82° 25.6' W
T I D A L D A T U M S
Tidal datums at APOLLO BEACH, HILLSBOROUGH BAY based on:
LENGTH OF SERIES: 13 MONTHS
TIME PERIOD: July 1990 - July 1991
TIDAL EPOCH: 1960-1978
CONTROL TIDE STATION: 8726520 ST. PETERSBURG, TAMPA BAY
Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in METERS:
MEAN HIGHER HIGH WATER MHHW = 0.749
MEAN HIGH WATER MHW = 0.654
North American Vertical Datum NAVD88 = 0.571
MEAN SEA LEVEL MSL = 0.401
MEAN TIDE LEVEL MTL = 0.398
MEAN LOW WATER MLW = 0.141
MEAN LOWER LOW WATER MLLW = 0.000
North American Vertical Datum (NAVD88)
Bench Mark Elevation Information In METERS above:
Stamping or Designation MLLW MHW
6537 A 1976 3.037 2.383
6537 B 1976 2.929 2.275
6537 C 1976 3.137 2.483
6537 E 1976 2.698 2.044
6537 G 1990 2.059 1.405
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 5 of 5
PUBLICATION DATE: 08/22/2000
Station ID: 8726537 SUPERCEDED DATE: 04/21/2003
Name: APOLLO BEACH, HILLSBOROUGH BAY
FLORIDA
NOAA Chart: 11413 Latitude: 27° 47.2' N
USGS Quad: Gibsonton Longitude: 82° 25.6' 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.