U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Datums Page Page 1 of 5
Station ID: 8722445 PUBLICATION DATE: 01/26/2010
Name: HOBE SOUND, STATE PARK
FL
NOAA Chart: 11474 Latitude: 27° 2.2' N ( 27.03670)
USGS Quad: HOBE SOUND Longitude: 80° 6.4' W ( -80.10670)
To reach the tidal bench marks from the intersection of State Highway A1A and
State Road 707 (South Beach Road) in Hobe Sound, proceed SE on State Road 707
for 5.3 km (3.3 mi) to the private drive leading to the Mead residence, then
turn right and proceed west for 0.3 km (0.2 mi) on the drive to its end. The
bench marks are located in the vicinity of the dock and along the sea wall
behind the residence. The tide gage and staff were located on the private dock.
T I D A L B E N C H M A R K S
PRIMARY BENCH MARK STAMPING: NO 3 1972
MONUMENTATION: Tidal Station disk VM#: 5491
AGENCY: National Geodetic Survey (NGS) IDB PID#: AF6987
SETTING CLASSIFICATION: Concrete sea wall OPUS PID:
LATITUDE: 27° 2.2' N ( 27.03670) LONGITUDE: 80° 6.4' W ( -80.10670)
The primary bench mark is a disk set flush on the south end of the sea wall, 58
m (190 ft) west of the back porch of the private residence, 24.51 m (80.4 ft)
south of bench mark NO 4 1972, 18.81 m (61.7 ft) north of bench mark NO 2 1972,
15.61 m (51.2 ft) NE of bench mark NO 1 1972, and 0.21 m (0.7 ft) north of the
south end of the sea wall.
BENCH MARK STAMPING: NO 4 1972
MONUMENTATION: Tidal Station disk VM#: 5492
AGENCY: National Geodetic Survey (NGS) IDB PID#: AF6988
SETTING CLASSIFICATION: Concrete sea wall OPUS PID:
LATITUDE: 27° 2.2' N ( 27.03670) LONGITUDE: 80° 6.4' W ( -80.10670)
The bench mark is a disk set flush on the sea wall, 25.73 m (84.4 ft) south of
the north end of the sea wall, 25.60 m (84.0 ft) south of bench mark NO 5 1972,
24.72 m (81.1 ft) north of the south end of the sea wall, and 24.51 m (80.4 ft)
north of bench mark NO 3 1972.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 2 of 5
Station ID: 8722445 PUBLICATION DATE: 01/26/2010
Name: HOBE SOUND, STATE PARK
FL
NOAA Chart: 11474 Latitude: 27° 2.2' N ( 27.03670)
USGS Quad: HOBE SOUND Longitude: 80° 6.4' W ( -80.10670)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: NO 5 1972
MONUMENTATION: Tidal Station disk VM#: 5493
AGENCY: National Geodetic Survey (NGS) IDB PID#: AF6989
SETTING CLASSIFICATION: Concrete sea wall OPUS PID:
LATITUDE: 27° 2.2' N ( 27.03670) LONGITUDE: 80° 6.4' W ( -80.10670)
The bench mark is a disk set flush in the north end of the sea wall, 64 m (210
ft) NW of the NW corner of the back porch of the private residence, 50.32 m
(165.1 ft) north of the south end of the sea wall, 25.60 m (84.0 ft) north of
bench mark NO 4 1972, and 0.24 m (0.8 ft) south of the north end of the sea
wall.
BENCH MARK STAMPING: M 308 1970
MONUMENTATION: Bench Mark disk VM#: 18934
AGENCY: US Coastal and Geodetic Survey
(USC&GS) IDB PID#: AF3020
SETTING CLASSIFICATION: Concrete Post OPUS PID:
LATITUDE: 27° 2.7' N ( 27.04500) LONGITUDE: 80° 6.4' W ( -80.10670)
The bench mark is a disk set in the top of a concrete post projecting 2-inches
above the level of the ground, 12.19 m (40.0 ft) west of the center line of
State Highway 707, 4.27 m (14.0 ft) south of the centerline of Devonshire Lane,
0.79 m (2.6 ft) east of the NE corner of a high fence around a private tennis
court, in line with a 6-foot high concrete east-west fence line, 0.18 m (0.6 ft)
west of a metal witness post, 0.30 m (1.0 ft) below the level of the highway,
and about level with the street.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 3 of 5
Station ID: 8722445 PUBLICATION DATE: 01/26/2010
Name: HOBE SOUND, STATE PARK
FL
NOAA Chart: 11474 Latitude: 27° 2.2' N ( 27.03670)
USGS Quad: HOBE SOUND Longitude: 80° 6.4' W ( -80.10670)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 2445 A 2005
MONUMENTATION: Tidal Station disk VM#: 18935
AGENCY: National Geodetic Survey (NGS) IDB PID#:
SETTING CLASSIFICATION: Stainless Steel Rod OPUS PID:
LATITUDE: 27° 2.1' N ( 27.03500) LONGITUDE: 80° 6.4' W ( -80.10670)
The benchmark is a stainless steel rod located 19.23 m (63.1 ft) north of bench
mark 2445 B 2005, 11.00 m (36.1 ft) north of the approximate centerline of the
asphalt drive leading to a boat dock, 3.38 m (11.1 ft) SE of bench mark No 3
1972, and 1.34 m (4.4 ft) NE of the NE corner of the concrete portion of the
dock. The benchmark is a stainless steel rod driven to refusal at a depth of
17.2 m (56.4 ft) with an NGS logo cap recessed 0.03 m (0.1 ft) below the level
of the ground and level with the asphalt drive, and the datum point recessed
0.09 m (0.3 ft) below the level of the NGS logo cap. NOTE: A magnet was placed
inside of the NGS logo cap.
BENCH MARK STAMPING: 2445 B 2005
MONUMENTATION: Tidal Station disk VM#: 18936
AGENCY: Florida Department of Environmental
Protection IDB PID#:
SETTING CLASSIFICATION: Concrete Monument OPUS PID:
LATITUDE: 27° 2.1' N ( 27.03500) LONGITUDE: 80° 6.4' W ( -80.10670)
The benchmark is a disk set in the top of a concrete monument recessed 0.03 m
(0.1 ft) below the level of the ground with access to the datum point had
through a 5-inch NGS logo cap, 19.23 m (63.1 ft) north of bench mark 2445 B
2005, 11.00 m (36.1 ft) north of the approximate centerline of the asphalt drive
leading to a boat dock, 3.38 m (11.1 ft) SE of bench mark disk No 3 1972, and
1.34 m (4.4 ft) NE of the NE corner of the concrete portion of the dock. NOTE:
A magnet was placed inside of the NGS logo cap.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 4 of 5
Station ID: 8722445 PUBLICATION DATE: 01/26/2010
Name: HOBE SOUND, STATE PARK
FL
NOAA Chart: 11474 Latitude: 27° 2.2' N ( 27.03670)
USGS Quad: HOBE SOUND Longitude: 80° 6.4' W ( -80.10670)
D A T U M S
Datums at HOBE SOUND, STATE PARK based on:
LENGTH OF SERIES: 2 MONTHS
TIME PERIOD: November 1972 - December 1972
TIDAL EPOCH: 1983-2001
CONTROL TIDE STATION: 8722371 SEWALL POINT. ST. LUCIE RIVER
Elevations of datums referred to Mean Lower Low Water (MLLW), in METERS:
MEAN HIGHER HIGH WATER MHHW = 0.599
North American Vertical Datum NAVD88 = 0.595
MEAN HIGH WATER MHW = 0.556
MEAN SEA LEVEL MSL = 0.302
MEAN TIDE LEVEL MTL = 0.299
MEAN LOW WATER MLW = 0.042
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 3 1972 1.464 0.908
NO 4 1972 1.464 0.908
NO 5 1972 1.453 0.897
M 308 1970 4.610 4.054
2445 A 2005 1.054 0.498
2445 B 2005 0.997 0.441
Foot Notes:
Geodetic heights of the bench marks meet all NOAA/NOS/NGS quality control
standards for Second Order, Class 1 leveling. It is advised that a confirmation
set of levels be established for bench marks M 308 1970, 2445 A 2005, and 2445 B
2005 to verify height differences before using tidal bench mark elevation
information.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 5 of 5
Station ID: 8722445 PUBLICATION DATE: 01/26/2010
Name: HOBE SOUND, STATE PARK
FL
NOAA Chart: 11474 Latitude: 27° 2.2' N ( 27.03670)
USGS Quad: HOBE SOUND Longitude: 80° 6.4' W ( -80.10670)
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.