U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Datums Page Page 1 of 7
Station ID: 8725916 PUBLICATION DATE: 06/02/2011
Name: CASEY KEY
FL
NOAA Chart: 11424 Latitude: 27° 9.2' N ( 27.15330)
USGS Quad: LAUREL Longitude: 82° 29.0' W ( -82.48330)
To reach the tidal bench marks from the intersection of U.S. Highway 41 and
state road 72 in Sarasota proceed 9.8 km (6.1 mi) south to a road leading to
Blackburn Point and Casey Key, proceed 2 km (1 mi) west on the road to Casey Key
turn left and go south for 3 km (2 mi) to Jeff Mathers resident. The bench
marks are located along the seawall. 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: 5916 A 1977
DESIGNATION: 872 5916 A TIDAL
MONUMENTATION: Tidal Station disk VM#: 6102
AGENCY: National Ocean Survey (NOS) IDB PID#: AG7747
SETTING CLASSIFICATION: Concrete sea wall OPUS PID:
LATITUDE: 28° 9.6' N ( 28.16000) LONGITUDE: 82° 29.2' W ( -82.48670)
The primary bench mark is a disk set in the top of a concrete seawall, 14.14 m
(46.4 ft) north of a wooden boat dock, 14 m (46 ft) east of the centerline of
the blacktop road, and 0.46 m (1.5 ft) south of the north end of the seawall.
BENCH MARK STAMPING: 5916 B 1977
DESIGNATION: 872 5916 B TIDAL
MONUMENTATION: Tidal Station disk VM#: 6103
AGENCY: National Ocean Survey (NOS) IDB PID#: AG7748
SETTING CLASSIFICATION: Concrete sea wall OPUS PID:
LATITUDE: 28° 9.6' N ( 28.16000) LONGITUDE: 82° 29.2' W ( -82.48670)
The bench mark is a disk set in the top of the sea wall, 24.38 m (80.0 ft) south
of Bench Mark 5916 A 1977, 10.36 m (34.0 ft) east of the centerline of a
blacktop rod, and 8.66 m (28.4 ft) south of the west end of the boat dock.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 2 of 7
Station ID: 8725916 PUBLICATION DATE: 06/02/2011
Name: CASEY KEY
FL
NOAA Chart: 11424 Latitude: 27° 9.2' N ( 27.15330)
USGS Quad: LAUREL Longitude: 82° 29.0' W ( -82.48330)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 5916 C 1977
DESIGNATION: 872 5916 C TIDAL
MONUMENTATION: Tidal Station disk VM#: 6104
AGENCY: National Ocean Survey (NOS) IDB PID#: AG7749
SETTING CLASSIFICATION: Concrete sea wall OPUS PID:
LATITUDE: 28° 9.6' N ( 28.16000) LONGITUDE: 82° 29.2' W ( -82.48670)
The bench mark is a disk set in the top of the concrete seawall, 22.25 m (73.0
ft) south of Bench Mark 5916 B 1977, and 11.28 m (37.0 ft) east of the
centerline of a blacktop road.
BENCH MARK STAMPING: 5916 D 1977
DESIGNATION: 872 5916 D TIDAL
MONUMENTATION: Tidal Station disk VM#: 6105
AGENCY: National Ocean Survey (NOS) IDB PID#: AG7750
SETTING CLASSIFICATION: Concrete sea wall OPUS PID:
LATITUDE: 28° 9.6' N ( 28.16000) LONGITUDE: 82° 29.2' W ( -82.48670)
The bench mark is a disk set in the top of the concrete sea wall, 33.83 m (111.0
ft) south of Bench Mark 5916 C 1977, and 11.28 m (37.0 ft) east of the
centerline of a blacktop road.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 3 of 7
Station ID: 8725916 PUBLICATION DATE: 06/02/2011
Name: CASEY KEY
FL
NOAA Chart: 11424 Latitude: 27° 9.2' N ( 27.15330)
USGS Quad: LAUREL Longitude: 82° 29.0' W ( -82.48330)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 5916 E 1977
DESIGNATION: 872 5916 E TIDAL
MONUMENTATION: Tidal Station disk VM#: 6106
AGENCY: National Ocean Survey (NOS) IDB PID#: AG7751
SETTING CLASSIFICATION: Concrete sea wall OPUS PID:
LATITUDE: 28° 9.6' N ( 28.16000) LONGITUDE: 82° 29.2' W ( -82.48670)
The bench mark is a disk set in the top of a concrete sea wall, 47.55 m (156.0
ft) south of Bench Mark 5916 D 1977, and 12.50 m (41.0 ft) east of the
centerline of a blacktop road.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 4 of 7
Station ID: 8725916 PUBLICATION DATE: 06/02/2011
Name: CASEY KEY
FL
NOAA Chart: 11424 Latitude: 27° 9.2' N ( 27.15330)
USGS Quad: LAUREL Longitude: 82° 29.0' W ( -82.48330)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: X 699 2007
DESIGNATION: X 699
MONUMENTATION: Bench Mark disk VM#: 19933
AGENCY: National Ocean Service (NOS) IDB PID#: DL2735
SETTING CLASSIFICATION: Stainless steel rod OPUS PID:
LATITUDE: 27° 8.2' N ( 27.13703) LONGITUDE: 82° 28.4' W ( -82.47411)
The bench mark is a stainless steel rod located 5.3 m (17.5 ft) east of the
approximate centerline of Casey Key Road (State Road 789), 4.9 m (16.0 ft) south
of the approximate extended centerline of a driveway at 945 Casey Key road
(State Road 789), 1.2 m (4.0 ft) SW of a 25 cm (10-inch) diameter palm tree, and
0.4 m (1.3 ft) west of a carsonite witness post. The bench mark is a stainless
steel rod driven to refusal at a depth of 7.3 m (23.9 ft)) with an NGS logo cap
flush with the ground and level with Casey Key Road (State Road 789), the datum
point being recessed 0.1 m (0.4 ft) below the level of the NGS logo cap.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 5 of 7
Station ID: 8725916 PUBLICATION DATE: 06/02/2011
Name: CASEY KEY
FL
NOAA Chart: 11424 Latitude: 27° 9.2' N ( 27.15330)
USGS Quad: LAUREL Longitude: 82° 29.0' W ( -82.48330)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: Y 699 2007
DESIGNATION: Y 699
MONUMENTATION: Bench Mark disk VM#: 19934
AGENCY: National Ocean Service (NOS) IDB PID#: DL2736
SETTING CLASSIFICATION: Concrete sea wall OPUS PID:
LATITUDE: 27° 9.1' N ( 27.15097) LONGITUDE: 82° 28.9' W ( -82.48108)
The bench mark is a disk set flush in the top of a concrete seawall and about
0.5 m (1.5 ft) below the level of Casey Key Road (State Road 789), 39.9 m (130.9
ft) east-NE of the approximate centerline of Casey Key Road (State Road 789),
13.1 m (43.0 ft) SE of the approximate center of the NW dock entrance, 8.0 m
(26.4 ft) NW of the approximate center of the SE dock entrance, and 0.2 m (0.7
ft) NE of a carsonite witness post.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 6 of 7
Station ID: 8725916 PUBLICATION DATE: 06/02/2011
Name: CASEY KEY
FL
NOAA Chart: 11424 Latitude: 27° 9.2' N ( 27.15330)
USGS Quad: LAUREL Longitude: 82° 29.0' W ( -82.48330)
T I D A L D A T U M S
Tidal datums at CASEY KEY based on:
LENGTH OF SERIES: 3 MONTHS
TIME PERIOD: October 1977 - December 1977
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 = 0.560
MEAN HIGH WATER MHW = 0.468
North American Vertical Datum NAVD88 = 0.408
MEAN SEA LEVEL MSL = 0.282
MEAN TIDE LEVEL MTL = 0.276
MEAN LOW WATER MLW = 0.083
MEAN LOWER LOW WATER MLLW = 0.000
North American Vertical Datum (NAVD88)
Bench Mark Elevation Information In METERS above:
Stamping or Designation MLLW MHW
5916 A 1977 1.441 0.973
5916 B 1977 1.479 1.011
5916 C 1977 1.482 1.014
5916 D 1977 1.489 1.021
5916 E 1977 1.515 1.047
X 699 2007 1.889 1.421
Y 699 2007 3.311 2.843
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 X 699 2007 and Y 699 2007 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 7 of 7
Station ID: 8725916 PUBLICATION DATE: 06/02/2011
Name: CASEY KEY
FL
NOAA Chart: 11424 Latitude: 27° 9.2' N ( 27.15330)
USGS Quad: LAUREL Longitude: 82° 29.0' W ( -82.48330)
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.