U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Datums Page Page 1 of 4
PUBLICATION DATE: 12/20/1990
Station ID: 8722784 SUPERCEDED DATE: 04/21/2003
Name: YAMATO, INTRACOASTAL WATERWAY
FLORIDA
NOAA Chart: 11466 Latitude: 26° 24.2' N
USGS Quad: DELRAY BEACH Longitude: 80° 4.2' W
To reach the tidal bench marks from the intersection of State Highway 794 West
(Yamato Road) and U.S. Highway 1 in north Boca Raton, proceed 0.45 mile (0.72
km) north on U.S. Highway 1 to Jeffrey Street, then 0.35 mile (0.56 km) east on
Jeffrey Street to its end. The bench marks are along the sea wall at Porta
Bella East Condominiums and on Jeffrey Street. The tide gage and staff were on
the sea wall just north of Bench Mark NO 3 1973.
T I D A L B E N C H M A R K S
PRIMARY BENCH MARK STAMPING: NO 1 1973
MONUMENTATION: Survey Disk VM#: 5637
AGENCY: PID#: AD5824
SETTING CLASSIFICATION: Concrete Sea Wall
The bench mark is set flush in the concrete sea wall, 157.3 feet (47.9 m) SSW of
the SE property corner of Porta Bella East Condominiums, 29.7 feet (9.1 m) south
of the east end of a chain link fence along the south side of Jeffrey Street,
and 4.0 feet (1.2 m) north of the second 150o corner south of the NE end of the
sea wall.
BENCH MARK STAMPING: NO 3 1973
MONUMENTATION: Survey Disk VM#: 5638
AGENCY: PID#: AD5826
SETTING CLASSIFICATION: Concrete Sea Wall
The bench mark is set flush in the concrete sea wall, 169.5 feet (51.7 m) south
of the first 150o corner south of the NE end of the sea wall, 117 feet (36 m)
north of Bench Mark NO 2 1973, 108.7 feet (33.1 m) SSW of the NE corner of the
pebble walkway around the swimming pool, and 50.8 feet (15.5 m) NNE of the SE
property corner of Porta Bella East Condominiums.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 2 of 4
PUBLICATION DATE: 12/20/1990
Station ID: 8722784 SUPERCEDED DATE: 04/21/2003
Name: YAMATO, INTRACOASTAL WATERWAY
FLORIDA
NOAA Chart: 11466 Latitude: 26° 24.2' N
USGS Quad: DELRAY BEACH Longitude: 80° 4.2' W
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: NO 4 1973
MONUMENTATION: Survey Disk VM#: 5639
AGENCY: PID#: AD5827
SETTING CLASSIFICATION: Concrete Sea Wall
The bench mark is set flush in the concrete sea wall, 177 feet (54 m) south of
the NE end of the sea wall, 166.5 feet (50.7 m) north of Bench Mark NO 3 1973,
58.8 feet (17.9 m) NNE of the NE corner of the pebble walkway around the
swimming pool, and 37.2 feet (11.3 m) SSE of the center of a fence gate of an
east/west fence on the east side of Porta Bella East Condominiums.
BENCH MARK STAMPING: 2784 F 1981
MONUMENTATION: Survey Disk VM#: 5640
AGENCY: PID#: AD5828
SETTING CLASSIFICATION: Concrete Box Drain
The bench mark is set flush in a concrete box drain, 51.8 feet (15.8 m) south of
a fence and hedge, 22.4 feet (6.8 m) south of the centerline of Jeffrey Street,
16.0 feet (4.9 m) east of the centerline of the west side of a circle drive at
the end of Jeffrey Street, 1.35 feet (0.41 m) west of the south corner of the
drain, and about level with the ground.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 3 of 4
PUBLICATION DATE: 12/20/1990
Station ID: 8722784 SUPERCEDED DATE: 04/21/2003
Name: YAMATO, INTRACOASTAL WATERWAY
FLORIDA
NOAA Chart: 11466 Latitude: 26° 24.2' N
USGS Quad: DELRAY BEACH Longitude: 80° 4.2' W
T I D A L D A T U M S
Tidal datums at YAMATO, INTRACOASTAL WATERWAY based on:
LENGTH OF SERIES: 1 MONTH
TIME PERIOD: APRIL 1973
TIDAL EPOCH: 1960-1978
CONTROL TIDE STATION: 8722706 BOYNTON BEACH
Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in FEET:
HIGHEST OBSERVED WATER LEVEL (04/03/1973) = 3.23
MEAN HIGHER HIGH WATER MHHW = 2.70
MEAN HIGH WATER MHW = 2.58
MEAN TIDE LEVEL MTL = 1.38
MEAN LOW WATER MLW = 0.18
MEAN LOWER LOW WATER MLLW = 0.00
LOWEST OBSERVED WATER LEVEL (05/03/1973) = -0.41
North American Vertical Datum (NAVD88)
Bench Mark Elevation Information In FEET above:
Stamping or Designation MLLW MHW
NO 1 1973 5.71 3.13
NO 3 1973 5.73 3.15
NO 4 1973 5.72 3.14
2784 F 1981 7.21 4.63
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 4 of 4
PUBLICATION DATE: 12/20/1990
Station ID: 8722784 SUPERCEDED DATE: 04/21/2003
Name: YAMATO, INTRACOASTAL WATERWAY
FLORIDA
NOAA Chart: 11466 Latitude: 26° 24.2' N
USGS Quad: DELRAY BEACH Longitude: 80° 4.2' 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.