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National Ocean Service
Datums Page Page 1 of 10
Station ID: 8724580 PUBLICATION DATE: 03/29/2019
Name: KEY WEST
FL
NOAA Chart: 11447 Latitude: 24° 33.0' N ( 24.55083)
USGS Quad: KEY WEST Longitude: 81° 48.5' W ( -81.80806)
To reach the tidal bench marks from Key West International Airport, proceed west
on Roosevelt Boulevard for 3.9 km (2.4 mi) to White Street, then NW on White
Street for 2.3 km (1.4 mi) to Southard Street, turn left onto Southard Street
and go west to the U.S. Naval Reservation main gate at Thomas Street, continue
0.3 km (0.2 mi) to a second gate at Emma Street. The bench marks are on the
Naval Base, near the County Courthouse, and along Front Street in downtown Key
West. A remote met station is located on the roof of the Florida Keys National
Marine Sanctuary administration building at 33 E Quay Road. The water level
station is located on the sea wall adjacent to the Florida Keys Eco Discovery
Center by the intersection of E Quay Rd and Angela St.
T I D A L B E N C H M A R K S
PRIMARY BENCH MARK STAMPING: 4580 E 1998
DESIGNATION: 872 4580 E
MONUMENTATION: Flange-encased Rod VM#: 13915
AGENCY: National Ocean Service (NOS) IDB PID#: AJ2450
SETTING CLASSIFICATION: Stainless steel rod OPUS PID#: AJ2450
LATITUDE: 24° 33.3' N ( 24.55422) LONGITUDE: 81° 48.4' W ( -81.80733)
The primary bench mark is a flange-encased rod 44.37m (145.6 ft) SSE of the
second light pole from the N end of the property, 44.17 m (144.91 ft) E of the W
inside face of the concrete pier face 30.91m (101.4 ft) N of the N end of
existing retaining wall of old building, 25.79m (84.6 ft) W of the E face of the
chain link property fence, and 25.69m (84.3 ft) E of the third light pole from
the N end of the property. The datum point is the top of a stainless steel rod
driven 7.0m (23.0 ft) to refusal and encased in a 5 inch (13 cm) pvc pipe 0.0m
(3.0 ft) long. Mark has logo and concrete kickblock.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 2 of 10
Station ID: 8724580 PUBLICATION DATE: 03/29/2019
Name: KEY WEST
FL
NOAA Chart: 11447 Latitude: 24° 33.0' N ( 24.55083)
USGS Quad: KEY WEST Longitude: 81° 48.5' W ( -81.80806)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 29 1923 8.140
DESIGNATION: 872 4580 TIDAL 29
MONUMENTATION: Tidal Station disk VM#: 706
AGENCY: US Coast and Geodetic Survey
(USC&GS) IDB PID#: AA0009
SETTING CLASSIFICATION: Concrete wall of a building OPUS PID:
LATITUDE: 24° 33.3' N ( 24.55481) LONGITUDE: 81° 48.4' W ( -81.80664)
The bench mark is a disk set vertically in the E concrete wall and at the NE
corner of a private residence , 12.04 m (39.5 ft) W of the W curb of Front
street (extended from the City of Key West), 10.67 m (35.01 ft) S of the S curb
of Eaton Street, and 1.22 m (4.00 ft) above the level of the ground.
BENCH MARK STAMPING: 25 1923 5.292
DESIGNATION: 872 4580 TIDAL 25
MONUMENTATION: Tidal Station disk VM#: 711
AGENCY: US Coast and Geodetic Survey
(USC&GS) IDB PID#: AA0004
SETTING CLASSIFICATION: Wall OPUS PID:
LATITUDE: 24° 33.6' N ( 24.55997) LONGITUDE: 81° 48.4' W ( -81.80608)
The bench mark is a disk set vertically in a wall of the SE bank, close to the
corner at the E side of the corner entrance, 11 m (36.1 ft) SE of the centerline
of Front street, 2.3 m (7.5 ft) SW of the SW curb of Duval Street, and 0.8 m
(2.6 ft) above the pavement.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 3 of 10
Station ID: 8724580 PUBLICATION DATE: 03/29/2019
Name: KEY WEST
FL
NOAA Chart: 11447 Latitude: 24° 33.0' N ( 24.55083)
USGS Quad: KEY WEST Longitude: 81° 48.5' W ( -81.80806)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 26 1923 9.482
DESIGNATION: 872 4580 TIDAL 26
MONUMENTATION: Tidal Station disk VM#: 712
AGENCY: US Coast and Geodetic Survey
(USC&GS) IDB PID#: AA0005
SETTING CLASSIFICATION: Brick wall of a building OPUS PID:
LATITUDE: 24° 33.5' N ( 24.55844) LONGITUDE: 81° 48.4' W ( -81.80681)
The bench mark is a disk set vertically in the E brick wall of the Key West
museum of art and history across the street from Mel Fisher museum, 45.7 m
(149.9 ft) SW of the center of the street intersection, 12.71 m (41.699 ft) W of
the west curb of Front street, 10.33 m (33.89 ft) S of the NE corner of the
building, 0.91 m (2.99 ft) N of the N end of the third step from top at entrace
to building and about 1.07 m (3.51 ft) above the level of the ground.
BENCH MARK STAMPING: 30 1923 16.417
DESIGNATION: 872 4580 TIDAL 30
MONUMENTATION: Tidal Station disk VM#: 714
AGENCY: US Coast and Geodetic Survey
(USC&GS) IDB PID#: AA0007
SETTING CLASSIFICATION: Courthouse wall OPUS PID:
LATITUDE: 24° 33.3' N ( 24.55464) LONGITUDE: 81° 48.2' W ( -81.80394)
The bench mark is a disk set vertically in the NE face of the old County
Courthouse, 30.2 m (99.1 ft) SW of the SW curb of Whitehead Street, 14.6 m (47.9
ft) NW of the center of the NE entrance to the building, 0.30 m (0.98 ft) SE of
the N corner of the building, and 1.07 m (3.51 ft) above the ground.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 4 of 10
Station ID: 8724580 PUBLICATION DATE: 03/29/2019
Name: KEY WEST
FL
NOAA Chart: 11447 Latitude: 24° 33.0' N ( 24.55083)
USGS Quad: KEY WEST Longitude: 81° 48.5' W ( -81.80806)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 14.324
DESIGNATION: 872 4580 TIDAL BASIC
MONUMENTATION: Bench Mark disk VM#: 716
AGENCY: US Coast and Geodetic Survey
(USC&GS) IDB PID#: AA0008
SETTING CLASSIFICATION: Concrete post OPUS PID:
LATITUDE: 24° 33.3' N ( 24.55472) LONGITUDE: 81° 48.2' W ( -81.80372)
The bench mark is a disk set flush in the top of a concrete monument bearing
the inscription United States Coast and Geodetic Survey basic bench mark, 21.6 m
(70.9 ft) E of the N corner of the old County Courthouse, 9.91 m (32.51 ft) SW
of the SW curb of Whitehead Street, 6.71 m (22.01 ft) from a low cement wall on
the Whitehead street side of the County Courthouse grounds, 5.79 m (19.0 ft) N
of the edge of a walk leading to the front steps of the courthouse, 2.93 m (9.61
ft) NW of the NW curb of the NE entrance to the old courthouse, and 0.9 m (3.0
ft) above the level of the sidewalk.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 5 of 10
Station ID: 8724580 PUBLICATION DATE: 03/29/2019
Name: KEY WEST
FL
NOAA Chart: 11447 Latitude: 24° 33.0' N ( 24.55083)
USGS Quad: KEY WEST Longitude: 81° 48.5' W ( -81.80806)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: KH-8 1962 JAX
DESIGNATION: KH 8
MONUMENTATION: Survey disk VM#: 1781
AGENCY: US Army Corps of Engineers (USE) IDB PID#: AA1753
SETTING CLASSIFICATION: Dock OPUS PID:
LATITUDE: 24° 33.4' N ( 24.55744) LONGITUDE: 81° 48.5' W ( -81.80867)
The bench mark is a disk set in the concrete dock 85.95 m (281.99 ft) W of the
NE corner of the dock, 12.59 m (41.3 ft) E of the NW corner of the dock, and
0.67 m (2.20 ft) N of the N edge of the dock. Note -In order to survey to this
mark you must obtain permission from captain Chad Cummingham director of marina
operation for Hilton, phone number 305-294-4000.
BENCH MARK STAMPING: 4580 C 1992
DESIGNATION: 872 4580 C
MONUMENTATION: Tidal Station disk VM#: 12415
AGENCY: National Ocean Survey (NOS) IDB PID:
SETTING CLASSIFICATION: Mooring bollard OPUS PID:
LATITUDE: 24° 33.3' N ( 24.55569) LONGITUDE: 81° 48.5' W ( -81.80794)
The bench mark is a disk set in the concrete surface of the second mooring
bollard S of the Admirals Slip along the sea wall near the tide station, 25.90 m
(84.97 ft) W of the U.S. Navy property line fence on the E side of the
condominiums, 20.73 m (68.01 ft) N of the NW corner of the N water valve pit,
14.33 m (47.01 ft) S of the S face of the Admirals Slip, 1.37m (4.49 ft) E of
the E face of the concrete bulkhead, and 0.18 m (0.59 ft) above the concrete
deck.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 6 of 10
Station ID: 8724580 PUBLICATION DATE: 03/29/2019
Name: KEY WEST
FL
NOAA Chart: 11447 Latitude: 24° 33.0' N ( 24.55083)
USGS Quad: KEY WEST Longitude: 81° 48.5' W ( -81.80806)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 4580 D 1993
DESIGNATION: 872 4580 D
MONUMENTATION: Tidal Station disk VM#: 13696
AGENCY: National Ocean Service (NOS) IDB PID:
SETTING CLASSIFICATION: mooring bollard OPUS PID:
LATITUDE: 24° 33.3' N ( 24.55453) LONGITUDE: 81° 48.5' W ( -81.80781)
The bench mark is a disk set in a concrete pad for a mooring bollard,
approximately 183 m (600.4 ft) S of the gage house, 49.07 m (160.99 ft) NW of
third light pole S of the gage house, 21.64 m (71.00 ft) S of the middle
concrete pad housing ship to shore power, 10.80 m (35.43 ft) NW of the NW corner
of the Concrete Power Building, and 0.91 m (2.99 ft) E of the sea wall.
BENCH MARK STAMPING: 4580 F 2016
DESIGNATION: 872 4580 F
MONUMENTATION: Flange-encased Rod VM#: 21877
AGENCY: National Ocean Service (NOS) IDB PID:
SETTING CLASSIFICATION: Flange encased rod OPUS PID:
LATITUDE: 24° 33.2' N ( 24.55339) LONGITUDE: 81° 48.4' W ( -81.80711)
The bench mark is a flange encased rod located along a paved access road on the
Truman Naval property, 16.0 m (4.9 ft) east of a sheet pile bulkhead running
parallel to a downgrade ramp (not adjacent to seawall), 10.25 m (3.1 ft) west of
the chain link fence corner post nearest the access road, 8.03 m (2.4 ft) north
of the centerline of access road, being the high point of a deep driven steel
rod driven to refusal 8.45 m (27.72ft) with an aluminum access cover, concrete
protective kick block, and protective PVC sleeve.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 7 of 10
Station ID: 8724580 PUBLICATION DATE: 03/29/2019
Name: KEY WEST
FL
NOAA Chart: 11447 Latitude: 24° 33.0' N ( 24.55083)
USGS Quad: KEY WEST Longitude: 81° 48.5' W ( -81.80806)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 4580 J 2017
DESIGNATION: 872 4580 J
MONUMENTATION: Survey disk VM#: 22473
AGENCY: National Ocean Service (NOS) IDB PID:
SETTING CLASSIFICATION: Concrete sea wall OPUS PID:
LATITUDE: 24° 33.1' N ( 24.55142) LONGITUDE: 81° 48.4' W ( -81.80747)
The bench mark is a disk located 251 ft (76.5 m) NW of the beginning of the
seawall on the south side of boat ramp, 146 ft (44.5 m) NNW of the northern most
corner of the Eco-Discovery building and 4.3 ft (1.3 m) ESE of the end of
seawall on the south side of boat ramp.
BENCH MARK STAMPING: 4580 H 2017
DESIGNATION: 872 4580 H
MONUMENTATION: Survey disk VM#: 22474
AGENCY: National Ocean Service (NOS) IDB PID:
SETTING CLASSIFICATION: Storm Drain OPUS PID:
LATITUDE: 24° 33.1' N ( 24.55106) LONGITUDE: 81° 48.5' W ( -81.80797)
The bench mark is a disk located 223 ft (68.0 m) WSW of the edge of seawall on
the south side of boat ramp, 123 ft (37.5 m) NE of black metal fence that runs
between city and NOAA property, 53.7 ft (16.4 m) north of the western most
corner of sanctuaries building.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 8 of 10
Station ID: 8724580 PUBLICATION DATE: 03/29/2019
Name: KEY WEST
FL
NOAA Chart: 11447 Latitude: 24° 33.0' N ( 24.55083)
USGS Quad: KEY WEST Longitude: 81° 48.5' W ( -81.80806)
T I D A L D A T U M S
Tidal datums at KEY WEST based on:
LENGTH OF SERIES: 19 YEARS
TIME PERIOD: January 1983 - December 2001
TIDAL EPOCH: 1983-2001
CONTROL TIDE STATION:
Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in METERS:
HIGHEST OBSERVED WATER LEVEL (10/24/2005) = 1.507
MEAN HIGHER HIGH WATER MHHW = 0.551
North American Vertical Datum NAVD88 = 0.538
MEAN HIGH WATER MHW = 0.463
MEAN SEA LEVEL MSL = 0.273
MEAN TIDE LEVEL MTL = 0.268
MEAN LOW WATER MLW = 0.073
MEAN LOWER LOW WATER MLLW = 0.000
LOWEST OBSERVED WATER LEVEL (02/19/1928) = -0.506
North American Vertical Datum (NAVD88)
Bench Mark Elevation Information In METERS above:
Stamping or Designation MLLW MHW
4580 E 1998 1.726 1.263
29 1923 8.140 2.592 2.129
25 1923 5.292 1.681 1.218
26 1923 9.482 3.010 2.547
30 1923 16.417 5.132 4.669
14.324 4.497 4.034
KH-8 1962 JAX 2.986 2.523
4580 C 1992 2.504 2.041
4580 D 1993 2.494 2.031
4580 F 2016 2.243 1.780
4580 J 2017 2.296 1.833
4580 H 2017 2.319 1.856
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 9 of 10
Station ID: 8724580 PUBLICATION DATE: 03/29/2019
Name: KEY WEST
FL
NOAA Chart: 11447 Latitude: 24° 33.0' N ( 24.55083)
USGS Quad: KEY WEST Longitude: 81° 48.5' W ( -81.80806)
Foot Notes:
Bench mark 4580 F 2016 is based on one differential leveling connection and does
not meet the quality control standards of the NOS. Therefore, caution should be
used when deriving elevations for this mark.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 10 of 10
Station ID: 8724580 PUBLICATION DATE: 03/29/2019
Name: KEY WEST
FL
NOAA Chart: 11447 Latitude: 24° 33.0' N ( 24.55083)
USGS Quad: KEY WEST Longitude: 81° 48.5' W ( -81.80806)
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.