U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Datums Page Page 1 of 8
PUBLICATION DATE: 06/28/2001
Station ID: 8724580 SUPERCEDED DATE: 04/21/2003
Name: KEY WEST
FLORIDA
NOAA Chart: 11447 Latitude: 24° 33.2' N
USGS Quad: KEY WEST Longitude: 81° 48.5' W
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. The tide gauge and staff are at the concrete sea wall near the north
property line of the Naval Base. NOTE: A pass to enter the Naval Base must be
obtained at the Boca Chica Naval Air Station.
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) PID#: AJ2450
SETTING CLASSIFICATION: Stainless steel rod in sleeve
The bench mark is a flange-encased rod located at the north end of the Truman
Annex property in a grassy area on the east side of the inside pier face and
inside the boat basin, 44.17 m (144.9 ft) east of the west inside face of the
concrete pier face, 37.70 m (123.7 ft) NNE of the NE corner of a two story white
block building, 37.19 m (122.0 ft) SE of the SE corner of a concrete electrical
building, 25.79 m (84.6 ft) west of the east chain link property fence, and
25.69 m (84.3 ft) east of the third light pole south of the north end of the
property. The datum point is the top of a stainless steel rod driven 7.0 m (23
ft) to refusal, in a sleeve extending to a depth of 0.9 m (3 ft), and encased in
a 5-inch NOS logo cap.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 2 of 8
PUBLICATION DATE: 06/28/2001
Station ID: 8724580 SUPERCEDED DATE: 04/21/2003
Name: KEY WEST
FLORIDA
NOAA Chart: 11447 Latitude: 24° 33.2' N
USGS Quad: KEY WEST Longitude: 81° 48.5' W
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) PID#: AA0009
SETTING CLASSIFICATION: Concrete wall of a building
The primary bench mark is a disk set vertically in the east concrete wall and at
the NE corner of the Officer Q and T Building, located at Key West Naval Station
near the extended center line of Eaton and Front Streets, 12.04 m (39.5 ft) west
of the west curb of Front Street (extended from the City of Key West), 10.67 m
(35.0 ft) south of the south curb of Eaton Street, and 1.22 m (4.0 ft) above
the level of the ground.
BENCH MARK STAMPING: 24 1923 6.529
DESIGNATION: 872 4580 TIDAL 24
MONUMENTATION: Tidal Station disk VM#: 710
AGENCY: US Coast and Geodetic Survey (USC&GS) PID#: AA0003
SETTING CLASSIFICATION: Concrete pillar of a building
The bench mark is a disk set vertically in the NW concrete face of a concrete
pillar, near the west corner of Cavanaghs Clothing Store, at Key West 0.08 km
(0.05 mi) NE along Front Street from its intersection with Duval Street, at the
intersection of Front and Ann Street, 2.90 m (9.5 ft) SE of the SE curb of Front
Street, 1.83 m (6.0 ft) NE of the NE curb of Ann Street, 0.15 m (0.5 ft) NE of
the west corner of the building, and 1.25 m (4.1 ft) above the level of the
sidewalk.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 3 of 8
PUBLICATION DATE: 06/28/2001
Station ID: 8724580 SUPERCEDED DATE: 04/21/2003
Name: KEY WEST
FLORIDA
NOAA Chart: 11447 Latitude: 24° 33.2' N
USGS Quad: KEY WEST Longitude: 81° 48.5' W
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) PID#: AA0005
SETTING CLASSIFICATION: Brick wall of a building
The bench mark is a disk set vertically in the east brick wall of Building No.
91 on the property of the Truman Annex Company, 0.6 km (0.4 mi) NW along
Whitehead Street from the Courthouse, at the intersection of Whitehead and Front
Street, 45.72 m (150.0 ft) SW of the center of the street intersection, 12.71 m
(41.7 ft) west of the west curb of Front Street, 10.33 m (33.9 ft) south of the
NE corner of the building, 0.91 m (3.0 ft) north of the north end of the third
step from top at entrance to building, and about 1.07 m (3.5 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) PID#: AA0007
SETTING CLASSIFICATION: Courthouse wall
The bench mark is a disk set vertically in a wall of the old County Courthouse
on Whitehead Street, between Fleming and Southard Streets, in the NE face of the
building, 30.18 m (99.0 ft) SW of the SW curb of Whitehead Street, 14.63 m (48.0
ft) NW of the center of the NE entrance to the building, 0.30 m (1.0 ft) SE of
the north corner of the building, and 1.07 m (3.5 ft) above the ground.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 4 of 8
PUBLICATION DATE: 06/28/2001
Station ID: 8724580 SUPERCEDED DATE: 04/21/2003
Name: KEY WEST
FLORIDA
NOAA Chart: 11447 Latitude: 24° 33.2' N
USGS Quad: KEY WEST Longitude: 81° 48.5' W
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) PID#: AA0008
SETTING CLASSIFICATION: Concrete monument
The bench mark is a disk set flush in the top of a concrete monument between
Fleming and Southard Streets, 21.64 m (71.0 ft) east of the north corner of the
old County Courthouse, 9.91 m (32.5 ft) SW of the SW curb of Whitehead Street,
6.71 m (22.0 ft) from a low cement wall on the Whitehead Street side of the
County Courthouse grounds, 5.79 m (19.0 ft) north of the edge of a walk leading
to the front steps of the courthouse, 2.93 m (9.6 ft) NW of the NW curb of the
NE entrance to the old courthouse, and 0.91 m (3.0 ft) above the level of the
sidewalk.
BENCH MARK STAMPING: KH-8 1962 JAX
DESIGNATION: KH 8
MONUMENTATION: Survey disk VM#: 1781
AGENCY: US Army Corps of Engineers (USE) PID#: AA1753
SETTING CLASSIFICATION: Dock
The bench mark is a disk set in the concrete dock west of the foot of Greene
Street, 86.01 m (282.2 ft) west of the NE corner of the dock, 12.59 m (41.3 ft)
east of the NW corner of the dock, and 0.67 m (2.2 ft) north of the north edge
of the dock.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 5 of 8
PUBLICATION DATE: 06/28/2001
Station ID: 8724580 SUPERCEDED DATE: 04/21/2003
Name: KEY WEST
FLORIDA
NOAA Chart: 11447 Latitude: 24° 33.2' N
USGS Quad: KEY WEST Longitude: 81° 48.5' W
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 4580 C 1992
DESIGNATION: 872 4580 C
MONUMENTATION: Tidal Station disk VM#: 12415
AGENCY: National Ocean Survey (NOS) PID:
SETTING CLASSIFICATION: Retaining wall
The bench mark is a disk set in the concrete surface of the second mooring
bollard south of the Admirals Slip along the sea wall near the tide station,
25.90 m (85.0 ft) west of the U.S. Navy property line fence on the east side of
the condominiums, 20.73 m (68.0 ft) north of the NW corner of the northern-most
water valve pit, 14.33 m (47.0 ft) south of the south face of the Admirals Slip,
and 0.18 m (0.6 ft) above the concrete deck.
BENCH MARK STAMPING: 4580 D 1993
DESIGNATION: 872 4580 D
MONUMENTATION: Tidal Station disk VM#: 13696
AGENCY: National Ocean Service (NOS) PID:
SETTING CLASSIFICATION: Concrete pad
The bench mark is a disk set flush in a concrete pad for a mooring bollard,
approximately 183 m (600 ft) south of the gage house, 49.07 m (161.0 ft) NW of
third light pole south of the gage house, 21.64 m (71.0 ft) south of the middle
concrete pad housing ship to shore power, 10.80 m (35.4 ft) NW of the NW corner
of the Concrete Power Building, and 0.91 m (3.0 ft) east of the sea wall.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 6 of 8
PUBLICATION DATE: 06/28/2001
Station ID: 8724580 SUPERCEDED DATE: 04/21/2003
Name: KEY WEST
FLORIDA
NOAA Chart: 11447 Latitude: 24° 33.2' N
USGS Quad: KEY WEST Longitude: 81° 48.5' W
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: KEY WEST GSL 1989
DESIGNATION: KEY WEST GSL
MONUMENTATION: Horizontal Station disk VM#: 15837
AGENCY: US Coast and Geodetic Survey (USC&GS) PID#: AA1645
SETTING CLASSIFICATION: Sea wall
The bench mark is a disk set in the concrete sea wall of the outer mole pier at
the Truman Annex Naval Air Station, 0.6 km (0.4 mi) north along the outer mole
pier from its south end, near the start of the curve of the sea wall to the NE,
22.25 m (73.0 ft) NW of the concrete base of the last light pole at the NNE end
of the pier, 10.36 m (34.0 ft) SSW of a steel ladder attached to the NW side of
the sea wall, 0.91 m (3.0 ft) north of the north corner of a bollard, and 0.91 m
(3.0 ft) ESE of the WNW edge of the sea wall.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 7 of 8
PUBLICATION DATE: 06/28/2001
Station ID: 8724580 SUPERCEDED DATE: 04/21/2003
Name: KEY WEST
FLORIDA
NOAA Chart: 11447 Latitude: 24° 33.2' N
USGS Quad: KEY WEST Longitude: 81° 48.5' W
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 1960 - December 1978
TIDAL EPOCH: 1960-1978
CONTROL TIDE STATION:
Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in METERS:
HIGHEST OBSERVED WATER LEVEL (09/08/1965) = 1.210
North American Vertical Datum NAVD88 = 0.608
MEAN HIGHER HIGH WATER MHHW = 0.561
MEAN HIGH WATER MHW = 0.472
MEAN SEA LEVEL MSL = 0.280
MEAN TIDE LEVEL MTL = 0.274
MEAN LOW WATER MLW = 0.073
MEAN LOWER LOW WATER MLLW = 0.000
LOWEST OBSERVED WATER LEVEL (02/19/1928) = -0.436
North American Vertical Datum (NAVD88)
Bench Mark Elevation Information In METERS above:
Stamping or Designation MLLW MHW
4580 E 1998 1.795 1.323
29 1923 8.140 2.661 2.189
24 1923 6.529 2.136 1.664
26 1923 9.482 3.080 2.607
30 1923 16.417 5.200 4.728
14.324 4.566 4.093
KH-8 1962 JAX 3.052 2.580
4580 C 1992 2.573 2.101
4580 D 1993 2.563 2.091
KEY WEST GSL 1989 2.168 1.696
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 8 of 8
PUBLICATION DATE: 06/28/2001
Station ID: 8724580 SUPERCEDED DATE: 04/21/2003
Name: KEY WEST
FLORIDA
NOAA Chart: 11447 Latitude: 24° 33.2' N
USGS Quad: KEY WEST Longitude: 81° 48.5' 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.