U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Datums Page Page 1 of 4
PUBLICATION DATE: 11/30/1987
Station ID: 8723534 SUPERCEDED DATE: 04/21/2003
Name: CARD SOUND BRIDGE, BARNES SOUND
FLORIDA
NOAA Chart: 11463 Latitude: 25° 17.2' N
USGS Quad: CARD SOUND Longitude: 80° 22.2' W
To reach the tidal bench marks from the intersection of U.S. Highway 1 and Card
Sound Road in Florida City proceed SE on Card Sound Road for 12.1 miles (19.5
km) to the Card Sound bridge. The bench marks are located on the fishing
catwalk located underneath the bridge. The tide gage and staff were located on
a bridge pile base on the west end of the west fishing catwalk under the bridge.
T I D A L B E N C H M A R K S
PRIMARY BENCH MARK STAMPING: N 316 1970
MONUMENTATION: Survey Disk VM#: 5910
AGENCY: PID#: AC1125
SETTING CLASSIFICATION: Concrete Walkway
The bench mark is set flush in a drill hole in the south side of the concrete
fishing pier below the west end of the bridge, in the base of the first pier
west of the steps, 1.9 feet (0.6 m) north of the north face of the south leg of
the pier, and 1.5 feet (0.3 m) below pier level.
BENCH MARK STAMPING: P 316 1970
MONUMENTATION: Survey Disk VM#: 5911
AGENCY: PID#: AC1127
SETTING CLASSIFICATION: Concrete Walkway
The bench mark is set flush in a drill hole in the north side of the concrete
fishing catwalk below the west end of the bridge, in the base of the fourth pier
east of the steps, 1.8 feet (0.5 m) south of the south face of the north leg of
the pier, and 1.5 feet (0.5 m) below pier level.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 2 of 4
PUBLICATION DATE: 11/30/1987
Station ID: 8723534 SUPERCEDED DATE: 04/21/2003
Name: CARD SOUND BRIDGE, BARNES SOUND
FLORIDA
NOAA Chart: 11463 Latitude: 25° 17.2' N
USGS Quad: CARD SOUND Longitude: 80° 22.2' W
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: Q 316 1970
MONUMENTATION: Survey Disk VM#: 5912
AGENCY: PID#: AC1124
SETTING CLASSIFICATION: Concrete Walkway
The bench mark is set flush in a drill hole on the south side of the concrete
fishing catwalk below the west end of the bridge, in the base of the fourth pier
east of the steps, 1.8 feet (0.5 m) north of the north face of the south leg,
and 1.5 feet (0.5 m) below pier level.
BENCH MARK STAMPING: R 316 1970
MONUMENTATION: Survey Disk VM#: 5913
AGENCY: PID#: AC1123
SETTING CLASSIFICATION: Concrete Walkway
The bench mark is set flush in a drill hole, on the north side if the concrete
fishing catwalk below the west end of the bridge, in the base of the sixth pier
east of the steps, 1.7 feet (0.5 m) south of the south face of the north leg of
the pier, and 1.5 feet (0.5 m) below pier level.
BENCH MARK STAMPING: S 316 1970
MONUMENTATION: Survey Disk VM#: 5914
AGENCY: PID#: AC1126
SETTING CLASSIFICATION: Concrete Walkway
The bench mark is set flush in a drill hole on the south side of the concrete
fishing catwalk below the west end of the bridge in the base of the eighth pier
east of the steps, 1.7 feet (0.5 m) north of the north face of the south leg of
the pier, and 1.5 feet (0.5 m) below pier level.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 3 of 4
PUBLICATION DATE: 11/30/1987
Station ID: 8723534 SUPERCEDED DATE: 04/21/2003
Name: CARD SOUND BRIDGE, BARNES SOUND
FLORIDA
NOAA Chart: 11463 Latitude: 25° 17.2' N
USGS Quad: CARD SOUND Longitude: 80° 22.2' W
T I D A L D A T U M S
Tidal datums at CARD SOUND BRIDGE, BARNES SOUND based on:
LENGTH OF SERIES: 9 MONTHS
TIME PERIOD: MAY 1970-APRIL 1971
TIDAL EPOCH: 1960-1978
CONTROL TIDE STATION: 8723289 CUTLER, BISCAYNE BAY
Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in FEET:
HIGHEST OBSERVED WATER LEVEL (10/18/1970) = 1.87
MEAN HIGHER HIGH WATER MHHW = 0.63
MEAN HIGH WATER MHW = 0.59
MEAN TIDE LEVEL MTL = 0.32
MEAN LOW WATER MLW = 0.06
MEAN LOWER LOW WATER MLLW = 0.00
* NATIONAL GEODETIC VERTICAL DATUM NGVD29 = -0.33
LOWEST OBSERVED WATER LEVEL (08/14/1971) = -0.98
* NGVD reference based on elevations published in Quad 250802, 1972, and NOS
leveling of 1982.
North American Vertical Datum (NAVD88)
Bench Mark Elevation Information In FEET above:
Stamping or Designation MLLW MHW
N 316 1970 6.19 5.60
P 316 1970 5.88 5.29
Q 316 1970 5.92 5.33
R 316 1970 5.88 5.29
S 316 1970 5.93 5.34
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 4 of 4
PUBLICATION DATE: 11/30/1987
Station ID: 8723534 SUPERCEDED DATE: 04/21/2003
Name: CARD SOUND BRIDGE, BARNES SOUND
FLORIDA
NOAA Chart: 11463 Latitude: 25° 17.2' N
USGS Quad: CARD SOUND Longitude: 80° 22.2' 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.