U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Datums Page Page 1 of 5
PUBLICATION DATE: 12/20/1990
Station ID: 8722761 SUPERCEDED DATE: 04/21/2003
Name: SOUTH DELRAY BEACH, INTRACOASTAL WATERWAY
FLORIDA
NOAA Chart: 11466 Latitude: 26° 26.8' N
USGS Quad: DELRAY BEACH Longitude: 80° 3.9' W
To reach the tidal bench marks from the intersection of U.S. Highway 1 and State
Highway S-806 (Atlantic Avenue) in Delray Beach, proceed south on U.S. Highway 1
for 1.2 miles (1.9 km) to a U-turn loop to U.S. Highway 1 north (oneway), go
north on U.S. Highway 1 for 0.1 mile (0.2 km) to the Delray Harbor Club
Apartments (1035 S. Federal Highway). The bench marks are in the area around
the marina. The tide gage and staff were on the Delray Harbor Club Apartments
pier.
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#: 5632
AGENCY: PID#: AD5823
SETTING CLASSIFICATION: Concrete Sea Wall
The bench mark is set flush in the concrete sea wall at the SW corner of the
southernmost sea wall at Delray Harbor Club Apartments, 68 feet (21 m) south of
the south edge of the dockhouse, 68 feet (21 m) south of the sea wall at the
north side of the parking lot, 66.2 feet (20.2 m) SSW of the SW corner of the
marina office, and 1.3 feet (0.4 m) east of the west end of the sea wall.
BENCH MARK STAMPING: DELRAY S BASE 1934 1962
MONUMENTATION: Survey Disk VM#: 5630
AGENCY: PID#: AD2687
SETTING CLASSIFICATION: Concrete Monument
The bench mark is set in the top of a concrete monument, 85 feet (26 m) NW of
the center of the railroad crossing at SE 10th Street, 49.2 feet (15.0 m) east
of the east rail of the northbound railroad track, 48 feet (15 m) north of the
centerline of SE 10th Street, 23 feet (7 m) north of the SW corner of a cyclone
fence around a Florida Power & Light (FPL) Company building, 20.7 feet (6.3 m)
west of the SW corner of the FPL building, 3 feet (1 m) north of a metal witness
post, 1.0 foot (0.3 m) below the track, and 0.5 foot (0.2 m) below ground level.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 2 of 5
PUBLICATION DATE: 12/20/1990
Station ID: 8722761 SUPERCEDED DATE: 04/21/2003
Name: SOUTH DELRAY BEACH, INTRACOASTAL WATERWAY
FLORIDA
NOAA Chart: 11466 Latitude: 26° 26.8' N
USGS Quad: DELRAY BEACH Longitude: 80° 3.9' W
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: DELRAY S BASE NO 4 1934 1962
MONUMENTATION: Survey Disk VM#: 5631
AGENCY: PID#: AD2688
SETTING CLASSIFICATION: Concrete Step
The bench mark is set in the SE corner of the concrete step near the SW corner
of the Florida Power & Light (FPL) Company building, about 69 feet (21 m) east
of the east rail of the northbound railroad track, 42 feet (13 m) north of the
centerline of SE 10th Street, 19.9 feet (6.1 m) east of Bench Mark DELRAY S BASE
1934 1962, 0.4 foot (0.1 m) north of the SW corner of the FPL building, and
about level with the track.
BENCH MARK STAMPING: NO 2 1973
MONUMENTATION: Survey Disk VM#: 5633
AGENCY: PID#: AD5822
SETTING CLASSIFICATION: Concrete Sea Wall
The bench mark is set flush in the concrete sea wall, 65 feet (20 m) north of
Bench Mark NO 1 1973, 23 feet (7 m) north of the NW corner of the swimming pool,
and 4.9 feet (1.5 m) SW of the SW corner of the dock-house office.
BENCH MARK STAMPING: NO 3 1973
MONUMENTATION: Survey Disk VM#: 5634
AGENCY: PID#: AD5821
SETTING CLASSIFICATION: Concrete Sea Wall
The bench mark is set flush in the concrete sea wall, 98 feet (30 m) west of the
SW corner of the dockhouse, 94 feet (29 m) west of Bench Mark NO 2 1973, and 17
feet (5 m) NNE of the NW corner of the cabana building.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 3 of 5
PUBLICATION DATE: 12/20/1990
Station ID: 8722761 SUPERCEDED DATE: 04/21/2003
Name: SOUTH DELRAY BEACH, INTRACOASTAL WATERWAY
FLORIDA
NOAA Chart: 11466 Latitude: 26° 26.8' N
USGS Quad: DELRAY BEACH Longitude: 80° 3.9' 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#: 5635
AGENCY: PID#: AD5820
SETTING CLASSIFICATION: Concrete Sea Wall
The bench mark is set flush in the concrete sea wall, 131 feet (40 m) west of
Bench Mark NO 3 1973, and 4.9 feet (1.5 m) NE of the NE corner of a storage
shed. Note: The bench mark is covered by a wood boardwalk and is inaccessible.
BENCH MARK STAMPING: NO 5 1973
MONUMENTATION: Survey Disk VM#: 5636
AGENCY: PID#: AD5819
SETTING CLASSIFICATION: Concrete Boat Lift Wall
The bench mark is set flush in the concrete boat lift wall, 42 feet (13 m) north
of Bench Mark NO 4 1973, 1.5 feet (0.5 m) west of the east end of the sea wall,
and 5 feet (2 m) north of the NE corner of the south wing of the Delray Harbor
Club Apartments.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 4 of 5
PUBLICATION DATE: 12/20/1990
Station ID: 8722761 SUPERCEDED DATE: 04/21/2003
Name: SOUTH DELRAY BEACH, INTRACOASTAL WATERWAY
FLORIDA
NOAA Chart: 11466 Latitude: 26° 26.8' N
USGS Quad: DELRAY BEACH Longitude: 80° 3.9' W
T I D A L D A T U M S
Tidal datums at SOUTH DELRAY BEACH, 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) = 3.38
MEAN HIGHER HIGH WATER MHHW = 2.80
MEAN HIGH WATER MHW = 2.68
MEAN TIDE LEVEL MTL = 1.43
* NATIONAL GEODETIC VERTICAL DATUM NGVD29 = 0.92
MEAN LOW WATER MLW = 0.18
MEAN LOWER LOW WATER MLLW = 0.00
LOWEST OBSERVED WATER LEVEL (05/03/1973) = -0.43
* NGVD is based on elevations published in Quad 260802, October 1969 and NOS
leveling of 1981.
North American Vertical Datum (NAVD88)
Bench Mark Elevation Information In FEET above:
Stamping or Designation MLLW MHW
NO 1 1973 7.37 4.69
DELRAY S BASE 1934 1962 18.63 15.95
DELRAY S BASE NO 4 1934 1962 20.33 17.65
NO 2 1973 7.38 4.70
NO 3 1973 7.38 4.70
NO 4 1973 7.37 4.69
NO 5 1973 7.32 4.64
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 5 of 5
PUBLICATION DATE: 12/20/1990
Station ID: 8722761 SUPERCEDED DATE: 04/21/2003
Name: SOUTH DELRAY BEACH, INTRACOASTAL WATERWAY
FLORIDA
NOAA Chart: 11466 Latitude: 26° 26.8' N
USGS Quad: DELRAY BEACH Longitude: 80° 3.9' 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.