U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Datums Page Page 1 of 5
Station ID: 8724529 PUBLICATION DATE: 01/23/2004
Name: RIVERIA CANAL, KEY WEST
FL
NOAA Chart: 11441 Latitude: 24° 33.9' N ( 24.56500)
USGS Quad: KEY WEST Longitude: 81° 45.1' W ( -81.75170)
To reach the tidal bench marks from the intersection of U.S. Highway 1 and State
Highway A1A (South Roosevelt Boulevard) on the east side of Key West, proceed SE
on State Highway A1A for 0.56 km (0.35 mi) to the bridge over the Riviera Canal.
The bench marks are located along State Highway A1A in the vicinity of the
bridge. The tide gage and staff were located on a private dock SW of the NW
corner of the bridge.
T I D A L B E N C H M A R K S
PRIMARY BENCH MARK STAMPING: NO 1 1974
DESIGNATION: 872 4529 TIDAL 1
MONUMENTATION: Tidal Station disk VM#: 10985
AGENCY: National Ocean Survey (NOS) IDB PID#: AA1004
SETTING CLASSIFICATION: Concrete sidewalk OPUS PID:
LATITUDE: 24° 33.8' N ( 24.56330) LONGITUDE: 81° 45.1' W ( -81.75170)
The primary bench mark is a disk set flush in the concrete sidewalk at the NE
corner of the State Highway A1A bridge over Riviera Canal, 101 m (332 ft) SSE of
bench mark P 121 1945, 10 m (33 ft) NNW of the SE corner of the bridge
bannister, and 9 m (31 ft) ENE of the centerline of the highway.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 2 of 5
Station ID: 8724529 PUBLICATION DATE: 01/23/2004
Name: RIVERIA CANAL, KEY WEST
FL
NOAA Chart: 11441 Latitude: 24° 33.9' N ( 24.56500)
USGS Quad: KEY WEST Longitude: 81° 45.1' W ( -81.75170)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: NO 2 1974
DESIGNATION: 872 4529 TIDAL 2
MONUMENTATION: Tidal Station disk VM#: 10986
AGENCY: National Ocean Survey (NOS) IDB PID#: AA1003
SETTING CLASSIFICATION: Concrete wing wall OPUS PID:
LATITUDE: 24° 33.8' N ( 24.56330) LONGITUDE: 81° 45.1' W ( -81.75170)
The bench mark is a disk set flush in the SE concrete wing wall of the State
Highway A1A bridge over Riviera Canal, 56 m (184 ft) SSE of bench mark NO 1
1974, 45 m (149 ft) NNW of the south end of the east bannister, 43 m (140 ft)
NNE of bench mark B 271 1966, 11 m (35 ft) ENE of the centerline of the highway,
and 0.30 m (1.0 ft) below the highway.
BENCH MARK STAMPING: NO 3 1974
DESIGNATION: 872 4529 TIDAL 3
MONUMENTATION: Tidal Station disk VM#: 10987
AGENCY: National Ocean Survey (NOS) IDB PID#: AA1002
SETTING CLASSIFICATION: Concrete wing wall OPUS PID:
LATITUDE: 24° 33.8' N ( 24.56330) LONGITUDE: 81° 45.1' W ( -81.75170)
The bench mark is a disk set flush in the SW concrete wing wall of the State
Highway A1A over Riviera Canal, 12 m (40 ft) WSW of the centerline of the
highway, 0.30 m (1.0 ft) east of the NW corner of the wingwall, and 1 m (3 ft)
below the highway.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 3 of 5
Station ID: 8724529 PUBLICATION DATE: 01/23/2004
Name: RIVERIA CANAL, KEY WEST
FL
NOAA Chart: 11441 Latitude: 24° 33.9' N ( 24.56500)
USGS Quad: KEY WEST Longitude: 81° 45.1' W ( -81.75170)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: B 271 1966
DESIGNATION: B 271
MONUMENTATION: Bench Mark disk VM#: 10988
AGENCY: US Coast and Geodetic Survey
(USC&GS) IDB PID#: AA0051
SETTING CLASSIFICATION: Concrete bannister OPUS PID:
LATITUDE: 24° 33.8' N ( 24.56330) LONGITUDE: 81° 45.0' W ( -81.75000)
The bench mark is a disk set on top of the SE concrete bannister of the State
Highway A1A bridge over Riviera Canal, 2.74 m (9.0 ft) NW of the SE end of the
bannister, 2 m (7 ft) NE of the NE curb of the highway, and 1.07 m (3.5 ft)
above sidewalk level.
BENCH MARK STAMPING: 4529 F 1982
DESIGNATION: 872 4529 F TIDAL
MONUMENTATION: Tidal Station disk VM#: 10990
AGENCY: National Ocean Survey (NOS) IDB PID#: AA1005
SETTING CLASSIFICATION: Concrete guardrail base OPUS PID:
LATITUDE: 24° 33.8' N ( 24.56330) LONGITUDE: 81° 45.1' W ( -81.75170)
The bench mark is a disk set in the concrete guardrail base at the north end of
the east bannister of the State Highway A1A bridge over Riviera Canal, 87.05 m
(285.6 ft) NNW of the north abutment of the bridge, 10.18 m (33.4 ft) ENE of the
centerline of the highway, 1.37 m (4.5 ft) SSE of the north end of the
bannister, and 0.30 m (1.0 ft) above highway level. NOTE: Mark not found in
2001 by US Power Squadron.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 4 of 5
Station ID: 8724529 PUBLICATION DATE: 01/23/2004
Name: RIVERIA CANAL, KEY WEST
FL
NOAA Chart: 11441 Latitude: 24° 33.9' N ( 24.56500)
USGS Quad: KEY WEST Longitude: 81° 45.1' W ( -81.75170)
T I D A L D A T U M S
Tidal datums at RIVERIA CANAL, KEY WEST based on:
LENGTH OF SERIES: 2 MONTHS
TIME PERIOD: November 1974 - December 1974
TIDAL EPOCH: 1983-2001
CONTROL TIDE STATION: 8724211 BIG PINE KEY VIADUCT
Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in METERS:
North American Vertical Datum NAVD88 = 0.420
MEAN HIGHER HIGH WATER MHHW = 0.388
MEAN HIGH WATER MHW = 0.301
MEAN SEA LEVEL MSL = 0.182
MEAN TIDE LEVEL MTL = 0.173
MEAN LOW WATER MLW = 0.045
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 1974 3.703 3.402
NO 2 1974 3.225 2.924
NO 3 1974 2.136 1.835
B 271 1966 3.157 2.856
4529 F 1982 1.563 1.262
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 5 of 5
Station ID: 8724529 PUBLICATION DATE: 01/23/2004
Name: RIVERIA CANAL, KEY WEST
FL
NOAA Chart: 11441 Latitude: 24° 33.9' N ( 24.56500)
USGS Quad: KEY WEST Longitude: 81° 45.1' W ( -81.75170)
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.