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Station ID: 8722746 SUPERCEDED DATE: 04/21/2003
Name: DELRAY BEACH, INTRACOASTAL WATERWAY
FLORIDA
NOAA Chart: 11466 Latitude: 26° 28.4' N
USGS Quad: DELRAY BEACH Longitude: 80° 3.7' W
To reach the tidal bench marks from the junction of State Highway S-806A (NE 8th
Street) and U.S. Highway 1, proceed east on State Highway S-806A for 0.4 mile
(0.6 km) to the bridge over the Intracoastal Waterway. The bench marks are on
the bridge. The tide gage and staff were on the SE fender of the bridge.
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#: 5626
AGENCY: PID#: AD5816
SETTING CLASSIFICATION: Concrete Bridge Sidewalk
The bench mark is set flush in the concrete sidewalk at the NW corner of the
bridge, and 15 feet (5 m) north of the centerline of the highway.
BENCH MARK STAMPING: BM 116 IWP D8 1951 1961
MONUMENTATION: Survey Disk VM#: 5625
AGENCY: PID#: AD2694
SETTING CLASSIFICATION: Concrete Bridge Sidewalk
The bench mark is set flush in the south concrete sidewalk of the bridge, 86.3
feet (26.3 m) east of the west end of the sidewalk, 16 feet (5 m) south of the
centerline of the highway, 1 foot (0.3 m) NE of the NE corner of the drawspan of
the bridge and the bridge tender house, and 1 foot (0.3 m) above the level of
the highway.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 2 of 4
PUBLICATION DATE: 12/20/1990
Station ID: 8722746 SUPERCEDED DATE: 04/21/2003
Name: DELRAY BEACH, INTRACOASTAL WATERWAY
FLORIDA
NOAA Chart: 11466 Latitude: 26° 28.4' N
USGS Quad: DELRAY BEACH Longitude: 80° 3.7' W
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: IWP 116 RM 1
MONUMENTATION: Survey Disk VM#: 5627
AGENCY: PID#: AD2693
SETTING CLASSIFICATION: Concrete Wing Wall
The bench mark is set flush in the top of the SW wingwall at the west end of the
bridge, 18.7 feet (5.7 m) south of the centerline of the highway and 1 foot (0.3
m) above the level of the highway.
BENCH MARK STAMPING: 9371A09
MONUMENTATION: Survey Disk VM#: 5628
AGENCY: PID#: AD5817
SETTING CLASSIFICATION: Concrete Bridge Sidewalk
The bench mark is set flush in the concrete sidewalk along the south side of the
bridge, about 70 feet (21 m) east of the west end of the bridge, 24 feet (7 m)
west of Bench Mark BM 116 IWP DB 1951 1961, 15 feet (5 m) south of the
centerline of the highway, and 6 feet (2 m) NW of the NW corner of the bridge
tender house.
BENCH MARK STAMPING: 2746 F
MONUMENTATION: Survey Disk VM#: 5629
AGENCY: PID#: AD5818
SETTING CLASSIFICATION: Concrete Bridge Abutment
The bench mark is set flush in the top of the NE abutment of the bridge, and 20
feet (6 m) north of the centerline of the highway.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 3 of 4
PUBLICATION DATE: 12/20/1990
Station ID: 8722746 SUPERCEDED DATE: 04/21/2003
Name: DELRAY BEACH, INTRACOASTAL WATERWAY
FLORIDA
NOAA Chart: 11466 Latitude: 26° 28.4' N
USGS Quad: DELRAY BEACH Longitude: 80° 3.7' W
T I D A L D A T U M S
Tidal datums at DELRAY BEACH, INTRACOASTAL WATERWAY based on:
LENGTH OF SERIES: 2 MONTHS
TIME PERIOD: APRIL-MAY 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) = 3.43
MEAN HIGHER HIGH WATER MHHW = 2.86
MEAN HIGH WATER MHW = 2.71
MEAN TIDE LEVEL MTL = 1.44
* NATIONAL GEODETIC VERTICAL DATUM NGVD29 = 0.94
MEAN LOW WATER MLW = 0.18
MEAN LOWER LOW WATER MLLW = 0.00
LOWEST OBSERVED WATER LEVEL (06/01/1973) = -0.55
* NGVD is based on elevations published in Quad 260802, March 1972 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 14.89 12.18
BM 116 IWP D8 1951 1961 16.22 13.51
IWP 116 RM 1 15.22 12.51
9371A09 15.88 13.17
2746 F 15.17 12.46
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 4 of 4
PUBLICATION DATE: 12/20/1990
Station ID: 8722746 SUPERCEDED DATE: 04/21/2003
Name: DELRAY BEACH, INTRACOASTAL WATERWAY
FLORIDA
NOAA Chart: 11466 Latitude: 26° 28.4' N
USGS Quad: DELRAY BEACH Longitude: 80° 3.7' 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.