U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Datums Page Page 1 of 6
Station ID: 8726738 PUBLICATION DATE: 04/21/2003
Name: SAFETY HARBOR, OLD TAMPA BAY
FL
NOAA Chart: 11413 Latitude: 27° 59.3' N ( 27.98830)
USGS Quad: SAFETY HARBOR Longitude: 82° 41.1' W ( -82.68500)
To reach the tidal bench marks from the intersection of North Bayshore Drive and
South Boulevard in Safety Harbor, proceed south on South Boulevard for 0.2 km
(0.1 mi) to a marina. The bench marks are along Main Street, South Boulevard,
and North Bayshore Drive near the marina. The tide gage and staff were on the
city pier in the harbor beyond the east end of South Boulevard.
T I D A L B E N C H M A R K S
PRIMARY BENCH MARK STAMPING: NO 1 1950
DESIGNATION: 872 6738 TIDAL 1
MONUMENTATION: Bench Mark disk VM#: 7550
AGENCY: US Coast and Geodetic Survey
(USC&GS) IDB PID#: AG0994
SETTING CLASSIFICATION: Concrete base OPUS PID:
LATITUDE: 27° 59.4' N ( 27.99000) LONGITUDE: 82° 41.3' W ( -82.68830)
The primary bench mark is a disk set in the concrete base for an arch at
Baranoffs Health Resort, in line with the north half of Main Street, 13.56 m
(44.5 ft) SE of the centerline of North Bayshore Drive, 4 m (13 ft) north of the
extended centerline of Main Street, 1.68 m (5.5 ft) SE of the NW concrete block
pillar at the entrance to the resort, 0.2 m (0.5 ft) north of the archway, 0.2 m
(0.5 ft) from the edge of the step, and at sidewalk level.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 2 of 6
Station ID: 8726738 PUBLICATION DATE: 04/21/2003
Name: SAFETY HARBOR, OLD TAMPA BAY
FL
NOAA Chart: 11413 Latitude: 27° 59.3' N ( 27.98830)
USGS Quad: SAFETY HARBOR Longitude: 82° 41.1' W ( -82.68500)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: COURTNEY L
DESIGNATION: COURTNEY L
MONUMENTATION: Survey disk VM#: 7553
AGENCY: Pinellas County IDB PID#: AG0467
SETTING CLASSIFICATION: Concrete post OPUS PID:
LATITUDE: 27° 59.3' N ( 27.98830) LONGITUDE: 82° 41.4' W ( -82.69000)
The bench mark is a disk set in the top of a concrete post, south of the
intersection of South Boulevard and South Bayshore Drive, 44.96 m (147.5 ft)
east of power light pole #9A-475, 42.06 m (138.0 ft) SE of the SE corner of a
sanitary sewer pumping station, 27.58 m (90.5 ft) SE of the centerline of South
Bayshore Drive, 25.91 m (85.0 ft) ENE of a 0.40 m (1.3 ft) palm tree, 23.16 m
(76.0 ft) SE of a 0.52 m (1.7 ft) diameter palm tree, and level with the ground.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 3 of 6
Station ID: 8726738 PUBLICATION DATE: 04/21/2003
Name: SAFETY HARBOR, OLD TAMPA BAY
FL
NOAA Chart: 11413 Latitude: 27° 59.3' N ( 27.98830)
USGS Quad: SAFETY HARBOR Longitude: 82° 41.1' W ( -82.68500)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: Y 31
DESIGNATION: Y 31
MONUMENTATION: Bench Mark disk VM#: 7554
AGENCY: US Coast and Geodetic Survey
(USC&GS) IDB PID#: AG5385
SETTING CLASSIFICATION: Concrete curb OPUS PID:
LATITUDE: 27° 59.4' N ( 27.99000) LONGITUDE: 82° 41.2' W ( -82.68670)
The bench mark is a disk set in the top of the curb in front of Baronoffs Health
Resort, at the east end of and in line with the south side of Main Street, 31 m
(101 ft) east of the center of the intersection of Main Street and First Avenue,
2 m (8 ft) south of the centerline of Main Street, 0.12 m (0.4 ft) above the
level of the road, and 0.09 m (0.3 ft) below the level of the sidewalk.
BENCH MARK STAMPING: 6738 F 1990
DESIGNATION: 872 6738 F
MONUMENTATION: Flange-encased Rod VM#: 7555
AGENCY: National Ocean Service (NOS) IDB PID#:
SETTING CLASSIFICATION: Stainless steel rod OPUS PID:
LATITUDE: 27° 59.3' N ( 27.98830) LONGITUDE: 82° 41.1' W ( -82.68500)
The bench mark is a flange encased rod located near the NE corner of the marina
parking lot, 12 m (41 ft) NW of the west end of the pier walkway, 8 m (25 ft) NE
of a 0.46 m x 1 m (1.5 ft x 2 ft) rectangular steel storm water catch basin in
the parking lot, 1.43 m (4.7 ft) west of the face of the east curb of the
parking lot, and 0.3 m (1.0 ft) south of the east-west 2 m (6 ft) high chain
link fence. The datum point is 10 cm (0.4 ft) below ground level, being the top
of a stainless steel rod driven 20.1 m (66 ft) to refusal, and encased in a
5-inch diameter logo cap.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 4 of 6
Station ID: 8726738 PUBLICATION DATE: 04/21/2003
Name: SAFETY HARBOR, OLD TAMPA BAY
FL
NOAA Chart: 11413 Latitude: 27° 59.3' N ( 27.98830)
USGS Quad: SAFETY HARBOR Longitude: 82° 41.1' W ( -82.68500)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 6738 G 1990
DESIGNATION: 872 6738 G
MONUMENTATION: Flange-encased Rod VM#: 7556
AGENCY: National Ocean Service (NOS) IDB PID#:
SETTING CLASSIFICATION: Stainless steel rod OPUS PID:
LATITUDE: 27° 59.3' N ( 27.98830) LONGITUDE: 82° 41.1' W ( -82.68500)
The bench mark is a flange encased rod located near the NW corner of the marina
basin, 58.06 m (190.5 ft) east of the centerline of South Bayshore Drive, 4.51 m
(14.8 ft) south of the south edge of the east-west sidewalk along the south side
of the marina parking lot, 1.80 m (5.9 ft) east of a concrete light pole, and
0.46 m (1.5 ft) NW of the NW corner of a 1 m (4 ft) high chain link fence
surrounding the marina basin. The datum point is 10 cm (0.4 ft) below ground
level, being the top of a stainless steel rod driven 20.1 m (66 ft) to refusal,
and encased in a 5- inch diameter logo cap.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 5 of 6
Station ID: 8726738 PUBLICATION DATE: 04/21/2003
Name: SAFETY HARBOR, OLD TAMPA BAY
FL
NOAA Chart: 11413 Latitude: 27° 59.3' N ( 27.98830)
USGS Quad: SAFETY HARBOR Longitude: 82° 41.1' W ( -82.68500)
T I D A L D A T U M S
Tidal datums at SAFETY HARBOR, OLD TAMPA BAY based on:
LENGTH OF SERIES: 5 Months
TIME PERIOD: January 1991 - May 1991
TIDAL EPOCH: 1983-2001
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 = 0.850
MEAN HIGH WATER MHW = 0.744
North American Vertical Datum NAVD88 = 0.537
MEAN SEA LEVEL MSL = 0.452
MEAN TIDE LEVEL MTL = 0.452
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
NO 1 1950 4.790 4.046
COURTNEY L 1.155 0.411
Y 31 4.721 3.977
6738 F 1990 1.634 0.890
6738 G 1990 1.649 0.905
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 6 of 6
Station ID: 8726738 PUBLICATION DATE: 04/21/2003
Name: SAFETY HARBOR, OLD TAMPA BAY
FL
NOAA Chart: 11413 Latitude: 27° 59.3' N ( 27.98830)
USGS Quad: SAFETY HARBOR Longitude: 82° 41.1' W ( -82.68500)
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.