U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Datums Page Page 1 of 5
PUBLICATION DATE: 06/22/1988
Station ID: 8536915 SUPERCEDED DATE: 04/21/2003
Name: FORTESCUE, DELAWARE BAY
NEW JERSEY
NOAA Chart: 12304 Latitude: 39° 14.2' N
USGS Quad: FORTESCUE Longitude: 75° 10.4' W
To reach the tidal bench marks from the intersection of Downe Avenue (Fortescue
Road) and New Jersey Avenue in Fortescue, proceed 0.5 mile (0.8 km) SE on New
Jersey Avenue to a lone wood pier on Delaware Bay. The bench marks are located
along New Jersey Avenue and Downe Avenue. The tide gage and tide staff were
located on the lone wood pier.
T I D A L B E N C H M A R K S
PRIMARY BENCH MARK STAMPING: 6915 F 1977
MONUMENTATION: Survey Disk VM#: 2789
AGENCY: PID:
SETTING CLASSIFICATION: Galvanized Steel Rod
The bench mark is located on the west side of New Jersey Avenue, 0.4 mile (0.6
km) southeasterly along New Jersey Avenue from its intersection with Downe
Avenue to a 25 MPH Speed Limit sign on the east side of New Jersey Avenue, 258
feet (79 m) NW of Bench Mark 6915 E 1977, 91 feet (28 m) NW of utility pole
#240, 77.5 feet (23.6 m) south of utility pole #239, 32.2 feet (9.8 m) SW of the
25 MPH Speed Limit sign, and 17.4 feet (5.3 m) west of centerline of New Jersey
Avenue. The bench mark is set 0.2 foot (0.1 m) below ground level, crimped to a
galvanized steel rod driven 40 feet (12 m) to refusal, and encased in a PVC pipe
and concrete kickblock.
BENCH MARK STAMPING: NO 2 1953
MONUMENTATION: Survey Disk VM#: 2784
AGENCY: PID#: JU1009
SETTING CLASSIFICATION: Concrete Footing
The bench mark is set flush in a concrete footing at the intersection of Downe
Avenue and Garrison Avenue on the NE side of concrete footing of gasoline sign
post, 39.9 feet (12.2 m) east of telephone pole #221 B 18616, 38.7 feet (11.8 m)
NE of the intersection of Downe Avenue and Garrison Avenue, and 20.2 feet (6.2
m) SE of south corner of Post Office.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 2 of 5
PUBLICATION DATE: 06/22/1988
Station ID: 8536915 SUPERCEDED DATE: 04/21/2003
Name: FORTESCUE, DELAWARE BAY
NEW JERSEY
NOAA Chart: 12304 Latitude: 39° 14.2' N
USGS Quad: FORTESCUE Longitude: 75° 10.4' W
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: NO 3 1953
MONUMENTATION: Survey Disk VM#: 2785
AGENCY: PID#: JU1011
SETTING CLASSIFICATION: Concrete Footing
The bench mark is located in east portion of a concrete footing of the chimney
on north side of the Ronald Loper residence, 45.4 feet (13.8 m) NE of centerline
of Garrison Avenue, and 22.2 feet (6.8 m) SE of south corner of Lillian
Hamiltons store and residence.
BENCH MARK STAMPING: NO 4 1953
MONUMENTATION: Survey Disk VM#: 2786
AGENCY: PID#: JU1010
SETTING CLASSIFICATION: Concrete Footing
The bench mark is set in east portion of a concrete footing of a television
antenna on Andrew Gerods property, 97.1 feet (29.6 m) NE of central line of Main
Street, 75.3 feet (23.0 m) SW of centerline of Garrison Avenue, 35.8 feet (10.9
m) SW from the south corner of a utility building at rear of Andrew Gerods
property, and 19.0 feet (5.8 m) east of east corner of Andrew Gerods chimney.
BENCH MARK STAMPING: NO 5 1953
MONUMENTATION: Survey Disk VM#: 2787
AGENCY: PID#: JU1012
SETTING CLASSIFICATION: Concrete Footing
The bench mark is set in the concrete footing of the set of cinder block steps
located on the NW side of Mr. Jack Wellers residence on the SW side of Main
Street, 34.6 feet (10.5 m) SE of the south corner of a garage located at the
rear of Mr. Rainears property, and 10.4 feet (3.2 m) from the east corner of Mr.
Rainears residence.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 3 of 5
PUBLICATION DATE: 06/22/1988
Station ID: 8536915 SUPERCEDED DATE: 04/21/2003
Name: FORTESCUE, DELAWARE BAY
NEW JERSEY
NOAA Chart: 12304 Latitude: 39° 14.2' N
USGS Quad: FORTESCUE Longitude: 75° 10.4' W
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 6915 E 1977
MONUMENTATION: Survey Disk VM#: 2788
AGENCY: PID:
SETTING CLASSIFICATION: Galvanized Steel Rod
The bench mark is located on the west side of New Jersey Avenue, 0.4 mile (0.6
km) SE along New Jersey Avenue from its intersection with Downe Avenue, 76.8
feet (23.4 m) NNE of a fire hydrant, 58.0 feet (17.7 m) ENE of a wood bulkhead,
21.2 feet (6.5 m) ENE of the centerline of New Jersey Avenue, and 6.9 feet (2.1
m) SE of wood utility pole #241. The bench mark is 1.5 feet (0.5 m) below
ground level, crimped to a galvanized steel rod driven 50 feet (15 m) to
refusal, and encased in a PVC pipe and concrete kickblock.
BENCH MARK STAMPING: 6915 G 1977
MONUMENTATION: Survey Disk VM#: 2790
AGENCY: PID:
SETTING CLASSIFICATION: Galvanized Steel Rod
The bench mark is located on the east side of New Jersey Avenue, 0.4 mile (0.6
km) SE along New Jersey Avenue from its intersection with Downe Avenue to wood
utility pole #237, 321 feet (98 m) NE of Bench Mark 6915 F 1977, 44.1 feet (13.4
m) south of wood utility pole #237, 20.3 feet (6.2 m) east of the centerline of
New Jersey Avenue, and 10.2 feet (3.1 m) north of a wood corner post of a wire
fence. The bench mark is set 0.2 foot (0.1 m) below ground level, crimped to a
galvanized steel rod driven 50 feet (15 m) to refusal, and encased in a PVC pipe
and concrete kickblock.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 4 of 5
PUBLICATION DATE: 06/22/1988
Station ID: 8536915 SUPERCEDED DATE: 04/21/2003
Name: FORTESCUE, DELAWARE BAY
NEW JERSEY
NOAA Chart: 12304 Latitude: 39° 14.2' N
USGS Quad: FORTESCUE Longitude: 75° 10.4' W
T I D A L D A T U M S
Tidal datums at FORTESCUE, DELAWARE BAY based on:
LENGTH OF SERIES: 9 MONTHS
TIME PERIOD: SEPTEMBER 1977 - AUGUST 1978
TIDAL EPOCH: 1960-1978
CONTROL TIDE STATION: 8557380 LEWES, DE
Elevations of tidal datums referred to Mean High Water (MHW), in FEET:
HIGHEST OBSERVED WATER LEVEL (10/14/1977) = 2.97
MEAN HIGHER HIGH WATER MHHW = 0.44
MEAN HIGH WATER MHW = 0.00
* NATIONAL GEODETIC VERTICAL DATUM NGVD29 = -3.81
* NGVD is based on elevations published in Quad 390752, dated June, 1982,
andNOS leveling of 1977-78.
North American Vertical Datum (NAVD88)
Bench Mark Elevation Information In FEET above:
Stamping or Designation MHW
6915 F 1977 3.04
NO 2 1953 2.37
NO 3 1953 3.62
NO 4 1953 3.29
NO 5 1953 2.34
6915 E 1977 2.46
6915 G 1977 2.42
Foot Notes:
The datums were computed by the NOS Direct Method due to flat low waters.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 5 of 5
PUBLICATION DATE: 06/22/1988
Station ID: 8536915 SUPERCEDED DATE: 04/21/2003
Name: FORTESCUE, DELAWARE BAY
NEW JERSEY
NOAA Chart: 12304 Latitude: 39° 14.2' N
USGS Quad: FORTESCUE Longitude: 75° 10.4' 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.