U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Datums Page Page 1 of 4
PUBLICATION DATE: 06/12/1985
Station ID: 8723232 SUPERCEDED DATE: 04/21/2003
Name: KEY BISCAYNE YACHT CLUB, KEY BISCAYNE
FLORIDA
NOAA Chart: 11465 Latitude: 25° 41.9' N
USGS Quad: KEY BISCAYNE Longitude: 80° 10.2' W
To reach the tidal bench marks from Miami proceed east 2.7 miles (4.3 km) on
Rickenbacker Causeway to Virginia Key, then south 2.6 miles (4.2 km) to the
traffic circle in Key Biscayne, then south 0.2 miles (0.3 km) to Harbor Drive
and proceed west 0.5 miles (0.8 km) on Harbor Drive to the Key Biscayne Yacht
Club. The bench marks are on the Yacht Club pier and the bulkhead. The tide
gage and staff were on the end of the T shaped pier with the fuel pumps.
T I D A L B E N C H M A R K S
PRIMARY BENCH MARK STAMPING: 3232 NO 1 1980
MONUMENTATION: Survey Disk VM#: 5800
AGENCY: PID:
SETTING CLASSIFICATION: Concrete Pier Deck
The bench mark is in the middle of the T shaped Key Biscayne Yacht Club pier
with the fuel pumps, 3.5 feet (1.1 m) from the end of the pier centered between
two gas pumps. The bench mark is set flush in the concrete pier deck.
BENCH MARK STAMPING: 3232 NO 2 1980
MONUMENTATION: Survey Disk VM#: 5801
AGENCY: PID:
SETTING CLASSIFICATION: Concrete Bulkhead
The bench mark is in the center of the bulkhead at the foot of the T shaped Key
Biscayne Yacht Club pier, 10 feet (3 m) NE of a large aluminum light pole. The
bench mark is set flush in the top of a concrete bulkhead.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 2 of 4
PUBLICATION DATE: 06/12/1985
Station ID: 8723232 SUPERCEDED DATE: 04/21/2003
Name: KEY BISCAYNE YACHT CLUB, KEY BISCAYNE
FLORIDA
NOAA Chart: 11465 Latitude: 25° 41.9' N
USGS Quad: KEY BISCAYNE Longitude: 80° 10.2' W
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 3232 NO 3 1980
MONUMENTATION: Survey Disk VM#: 5802
AGENCY: PID:
SETTING CLASSIFICATION: Concrete Bulkhead
The bench mark is on the north corner of the launching ramp of the Key Biscayne
Yacht Club, 0.5 foot (0.2 m) from the edge of the bulkhead. The bench mark is
set flush in the top of the concrete bulkhead.
BENCH MARK STAMPING: 3232 NO 4 1980
MONUMENTATION: Survey Disk VM#: 5803
AGENCY: PID:
SETTING CLASSIFICATION: Concrete Bulkhead
The bench mark is in a bulkhead in line with the center of a finger pier, 31
feet (9.4 m) from the south corner of the launching ramp. The bench mark is set
flush in the top of the concrete bulkhead.
BENCH MARK STAMPING: 3232 NO 5 1980
MONUMENTATION: Survey Disk VM#: 5804
AGENCY: PID:
SETTING CLASSIFICATION: Concrete Bulkhead
The bench mark is 15.5 feet (4.7 m) NW of a telephone booth, and centered on the
top of the bulkhead just before it bends south. The bench mark is set flush on
the top of the concrete bulkhead.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 3 of 4
PUBLICATION DATE: 06/12/1985
Station ID: 8723232 SUPERCEDED DATE: 04/21/2003
Name: KEY BISCAYNE YACHT CLUB, KEY BISCAYNE
FLORIDA
NOAA Chart: 11465 Latitude: 25° 41.9' N
USGS Quad: KEY BISCAYNE Longitude: 80° 10.2' W
T I D A L D A T U M S
Tidal datums at KEY BISCAYNE YACHT CLUB, KEY BISCAYNE based on:
LENGTH OF SERIES: 4 MONTHS
TIME PERIOD: JANUARY-APRIL 1981
TIDAL EPOCH: 1960-1978
CONTROL TIDE STATION: 8723170 MIAMI BEACH
Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in FEET:
HIGHEST OBSERVED WATER LEVEL (05/02/1981) = 2.88
MEAN HIGHER HIGH WATER MHHW = 2.18
MEAN HIGH WATER MHW = 2.13
MEAN TIDE LEVEL MTL = 1.13
MEAN LOW WATER MLW = 0.13
MEAN LOWER LOW WATER MLLW = 0.00
LOWEST OBSERVED WATER LEVEL (04/06/1981) = -0.84
Bench Mark Elevation Information In FEET above:
Stamping or Designation MLLW MHW
3232 NO 1 1980 4.04 1.91
3232 NO 2 1980 4.94 2.81
3232 NO 3 1980 5.28 3.15
3232 NO 4 1980 5.26 3.13
3232 NO 5 1980 5.28 3.15
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 4 of 4
PUBLICATION DATE: 06/12/1985
Station ID: 8723232 SUPERCEDED DATE: 04/21/2003
Name: KEY BISCAYNE YACHT CLUB, KEY BISCAYNE
FLORIDA
NOAA Chart: 11465 Latitude: 25° 41.9' N
USGS Quad: KEY BISCAYNE Longitude: 80° 10.2' 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.