U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Datums Page Page 1 of 4
PUBLICATION DATE: 04/30/1987
Station ID: 8722371 SUPERCEDED DATE: 04/21/2003
Name: SEWALL POINT, INDIAN RIVER
FLORIDA
NOAA Chart: 11474 Latitude: 27° 10.5' N
USGS Quad: ST. LUCIE INLET Longitude: 80° 11.3' W
To reach the tidal bench marks from the courthouse on State Highway A1A in
Stuart, proceed 3.3 miles (5.3 km) east on State Highway A1A (East Ocean
Boulevard) to the community of Sewall Point, turn right at the Sewall Point Road
intersection and proceed 2.1 miles (3.4 km) south on Sewall Point Road to the
residence of Mr. A. R. Moyer, Jr. The tide gage and staff were on the Indian
River, on the Moyer pier. The bench marks are near the residences of A. R.
Moyer, Harold Hock, and W. J. Fields.
T I D A L B E N C H M A R K S
PRIMARY BENCH MARK STAMPING: SEAWALL 1898 1969 NO 5
MONUMENTATION: Survey Disk VM#: 5448
AGENCY: PID#: AF3181
SETTING CLASSIFICATION: Concrete Monument
The bench mark is set flush in a concrete monument on the Fields property, 55
feet (17 m) NNW of the edge of the river bluff, 30.5 feet (9.3 m) ENE of the SE
corner of the Fields residence, 13.0 feet (4.0 m) east of a 0.8-foot (0.2 m)
diameter palm tree, and 0.7 foot (0.2 m) below ground level.
BENCH MARK STAMPING: SEAWALL 1898 1969 NO 4
MONUMENTATION: Survey Disk VM#: 5447
AGENCY: PID#: AF3134
SETTING CLASSIFICATION: Concrete Monument
The bench mark is set in a concrete monument in a thick clump of aloe vera
plants on the Fields property, 43 feet (13 m) west of the west edge of a
swimming pool, 6.5 feet (2.0 m) NW of a palm tree, 1.0 foot (0.3 m) NNW of a
steel witness post, and 0.2 foot (0.1 m) below ground level.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 2 of 4
PUBLICATION DATE: 04/30/1987
Station ID: 8722371 SUPERCEDED DATE: 04/21/2003
Name: SEWALL POINT, INDIAN RIVER
FLORIDA
NOAA Chart: 11474 Latitude: 27° 10.5' N
USGS Quad: ST. LUCIE INLET Longitude: 80° 11.3' W
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: IWM 8 1960 FLAJACKSONVILLE
MONUMENTATION: Survey Disk VM#: 5449
AGENCY: PID#: AF3132
SETTING CLASSIFICATION: Concrete Monument
The bench mark is set in a concrete monument in a dense vine growth near the
south end of Sewall Point on the west bank of the Indian River, 216 feet (66
m) SE of the centerline of the road, 46 feet (14 m) east of the front door of
the Moyer residence, 9 feet (3 m) south of a 0.8-foot (0.2 m) diameter palm
tree, 3 feet (1 m) west of the edge of the river bluff, 1.1 feet (0.3 m) north
of a metal witness post, 6 feet (2 m) below road level, and 1 foot (0.3 m) above
ground level.
BENCH MARK STAMPING: NO 1 A 1969
MONUMENTATION: Survey Disk VM#: 5450
AGENCY: PID#: AF3182
SETTING CLASSIFICATION: Concrete Patio
The bench mark is set flush in a drill hole in the Moyer front patio, which
faces the river, at the north end of the southernmost sliding-glass door, 20
feet (6 m) NW of a 1-foot (0.3 m) diameter palm tree, 15.5 feet (4.7 m) NW of
the SE corner of the residence, and 1 foot (0.3 m) east of the residence.
BENCH MARK STAMPING: NO 2 A 1969
MONUMENTATION: Survey Disk VM#: 5451
AGENCY: PID#: AF3183
SETTING CLASSIFICATION: Concrete Slab
The bench mark is set flush in a drill hole on the south side of the Moyer
garage, in the top of a garbage can slab, 32 feet (10 m) NE of the SW corner of
the residence, 25 feet (8 m) SW of the SE corner of the residence, and 4 feet (1
m) SE of the SE wall.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 3 of 4
PUBLICATION DATE: 04/30/1987
Station ID: 8722371 SUPERCEDED DATE: 04/21/2003
Name: SEWALL POINT, INDIAN RIVER
FLORIDA
NOAA Chart: 11474 Latitude: 27° 10.5' N
USGS Quad: ST. LUCIE INLET Longitude: 80° 11.3' W
T I D A L D A T U M S
Tidal datums at SEWALL POINT, INDIAN RIVER based on:
LENGTH OF SERIES: 12 MONTHS
TIME PERIOD: JULY 1969-JUNE 1970
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 (10/31/1969) = 3.32
MEAN HIGHER HIGH WATER MHHW = 1.18
MEAN HIGH WATER MHW = 1.07
MEAN TIDE LEVEL MTL = 0.60
* NATIONAL GEODETIC VERTICAL DATUM NGVD29 = 0.34
MEAN LOW WATER MLW = 0.13
MEAN LOWER LOW WATER MLLW = 0.00
LOWEST OBSERVED WATER LEVEL (04/24/1970) = -0.83
* NGVD reference based on elevations published in Quad 270802, 1972, and NOS
leveling of 1980.
North American Vertical Datum (NAVD88)
Bench Mark Elevation Information In FEET above:
Stamping or Designation MLLW MHW
SEAWALL 1898 1969 NO 5 36.59 35.52
SEAWALL 1898 1969 NO 4 32.58 31.51
IWM 8 1960 FLAJACKSONVILLE 21.50 20.43
NO 1 A 1969 23.99 22.92
NO 2 A 1969 24.06 22.99
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 4 of 4
PUBLICATION DATE: 04/30/1987
Station ID: 8722371 SUPERCEDED DATE: 04/21/2003
Name: SEWALL POINT, INDIAN RIVER
FLORIDA
NOAA Chart: 11474 Latitude: 27° 10.5' N
USGS Quad: ST. LUCIE INLET Longitude: 80° 11.3' 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.