U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Datums Page Page 1 of 5
PUBLICATION DATE: 03/21/1990
Station ID: 8536581 SUPERCEDED DATE: 04/21/2003
Name: BIDWELL CREEK ENTRANCE, DELAWARE BAY
NEW JERSEY
NOAA Chart: 12304 Latitude: 39° 7.7' N
USGS Quad: HEISLERVILLE Longitude: 74° 53.5' W
To reach the tidal bench marks from the intersection of State Highway 47 and
Reeds Beach Road in Reeds Beach, proceed NW on Reeds Beach Road for 1 mile (1.6
km) to Beach Avenue, go north on Beach Avenue for about 0.7 mile (1.1 km) to the
entrance driveway to Captain Walts Marina. The bench marks are along Beach
Avenue and along the entrance driveway to the marina. The tide gage and staff
were on the marinas pier.
T I D A L B E N C H M A R K S
PRIMARY BENCH MARK STAMPING: 6581 C 1977
MONUMENTATION: Survey Disk VM#: 2780
AGENCY: PID:
SETTING CLASSIFICATION: Galvanized Steel Rod
The bench mark is along Beach Avenue approximately 0.6 mile (1.0 km) north of
the intersection with Reeds Beach Road, 436.0 feet (132.9 m) south of Bench Mark
6581 B 1977, 57.7 feet (17.6 m) NE of a utility pole with electric meter
attached, 17.5 feet (5.3 m) east of the centerline of Beach Avenue, 10.0 feet
(3.0 m) west of a steel guy wire post, and 4.7 feet (1.4 m) SE of utility pole
#W25294. The bench mark is 0.2 foot (0.1 m) below ground level, crimped to a
galvanized steel rod driven 50 feet (15 m).
BENCH MARK STAMPING: 6581 B 1977
MONUMENTATION: Survey Disk VM#: 2779
AGENCY: PID:
SETTING CLASSIFICATION: Galvanized Steel Rod
The bench mark is along Beach Avenue at the entrance driveway to Capt. Walts
Marina, 108.5 feet (33.1 m) west of utility pole #W29628, 62.7 feet (19.1 m)
south of a No Trespassing sign on the north side of the entrance driveway, 34.0
feet (10.4 m) east of the centerline of Beach Avenue, 32.2 feet (9.8 m) north of
utility pole #W29627, 27.3 feet (8.3 m) SE of the south gate post of the marina
entrance, and 10.9 feet (3.3 m) east of a steel cable fence. The bench mark is
0.2 foot (0.1 m) below ground level, crimped to a galvanized steel rod driven 50
feet (15 m).
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 2 of 5
PUBLICATION DATE: 03/21/1990
Station ID: 8536581 SUPERCEDED DATE: 04/21/2003
Name: BIDWELL CREEK ENTRANCE, DELAWARE BAY
NEW JERSEY
NOAA Chart: 12304 Latitude: 39° 7.7' N
USGS Quad: HEISLERVILLE Longitude: 74° 53.5' W
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 6581 D 1977
MONUMENTATION: Survey Disk VM#: 2781
AGENCY: PID:
SETTING CLASSIFICATION: Galvanized Steel Rod
The bench mark is along Beach Avenue approximately 0.55 mile (0.89 km) north of
the intersection with Reeds Beach Road, 307.5 feet (93.7 km) south of Bench Mark
6581 C 1977, 88.3 feet (26.9 m) south of utility pole #W25293, 16.0 feet (4.9 m)
east of the centerline of Beach Avenue, and 4.7 feet (1.4 m) SW of a cedar tree.
The bench mark is 0.2 foot (0.1 m) below ground level, crimped to a galvanized
steel rod driven 50 feet (15 m).
BENCH MARK STAMPING: 6581 E 1977
MONUMENTATION: Survey Disk VM#: 2782
AGENCY: PID:
SETTING CLASSIFICATION: Galvanized Steel Rod
The bench mark is along Beach Avenue approximately 0.5 mile (0.8 km) north of
the intersection with Reeds Beach Road, 312.0 feet (95.1 m) south of Bench Mark
6581 D 1977, 16.0 feet (4.9 m) east of the centerline of Beach Avenue, 14.6 feet
(4.5 m) SW of a utility pole with electric meter attached, and 5.6 feet (1.7 m)
north of utility pole #W16173. The bench mark is 0.2 foot (0.1 m) below
ground level, crimped to a galvanized steel rod driven 50 feet (15 m).
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 3 of 5
PUBLICATION DATE: 03/21/1990
Station ID: 8536581 SUPERCEDED DATE: 04/21/2003
Name: BIDWELL CREEK ENTRANCE, DELAWARE BAY
NEW JERSEY
NOAA Chart: 12304 Latitude: 39° 7.7' N
USGS Quad: HEISLERVILLE Longitude: 74° 53.5' W
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 6581 F 1984
MONUMENTATION: Survey Disk VM#: 2783
AGENCY: PID:
SETTING CLASSIFICATION: Stainless Steel Rod
The bench mark is located at Captain Walts Marina, approximately 0.1 mile (0.2
km) east of Beach Avenue, 173.1 feet (52.8 m) east of utility pole #W36225, 17.0
feet (5.2 m) south of the centerline of the entrance driveway, and 1 foot (0.3
m) north of an orange fiberglass witness post. The bench mark is crimped to
stainless steel rod driven 51 feet (16 m), and encased in a 4-inch PVC pipe and
concrete kickblock.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 4 of 5
PUBLICATION DATE: 03/21/1990
Station ID: 8536581 SUPERCEDED DATE: 04/21/2003
Name: BIDWELL CREEK ENTRANCE, DELAWARE BAY
NEW JERSEY
NOAA Chart: 12304 Latitude: 39° 7.7' N
USGS Quad: HEISLERVILLE Longitude: 74° 53.5' W
T I D A L D A T U M S
Tidal datums at BIDWELL CREEK ENTRANCE, DELAWARE BAY based on:
LENGTH OF SERIES: 8 MONTHS
TIME PERIOD: NOVEMBER 1977-OCTOBER 1978
TIDAL EPOCH: 1960-1978
CONTROL TIDE STATION: 8557380 LEWES, DE
Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in FEET:
HIGHEST OBSERVED WATER LEVEL (10/14/1977) = 8.54
MEAN HIGHER HIGH WATER MHHW = 6.37
MEAN HIGH WATER MHW = 5.96
MEAN TIDE LEVEL MTL = 3.07
MEAN LOW WATER MLW = 0.19
MEAN LOWER LOW WATER MLLW = 0.00
LOWEST OBSERVED WATER LEVEL (12/10/1977) = -1.50
Bench Mark Elevation Information In FEET above:
Stamping or Designation MLLW MHW
6581 C 1977 7.90 1.94
6581 B 1977 9.40 3.44
6581 D 1977 8.07 2.11
6581 E 1977 9.11 3.15
6581 F 1984 6.75 0.79
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 5 of 5
PUBLICATION DATE: 03/21/1990
Station ID: 8536581 SUPERCEDED DATE: 04/21/2003
Name: BIDWELL CREEK ENTRANCE, DELAWARE BAY
NEW JERSEY
NOAA Chart: 12304 Latitude: 39° 7.7' N
USGS Quad: HEISLERVILLE Longitude: 74° 53.5' 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.