U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Datums Page Page 1 of 5
Station ID: 8534244 PUBLICATION DATE: 05/01/2003
Name: GRAVELING POINT
NJ
NOAA Chart: 12316 Latitude: 39° 32.4' N ( 39.54000)
USGS Quad: NEW GRETNA Longitude: 74° 23.2' W ( -74.38670)
To reach the tidal bench marks from the south end of Tuckerton at the
intersection of U.S. Route 9 and Radio Road, proceed SE on Radio Road for 8 km
(5 mi) to the end of the road at the Great Bay Marina. The bench marks are
located along Radio Road. The tide station was located on the Great Bay Marina
bulkhead.
T I D A L B E N C H M A R K S
PRIMARY BENCH MARK STAMPING: 4244 A 1977
DESIGNATION: 853 4244 A TIDAL
MONUMENTATION: Tidal Station disk VM#: 2660
AGENCY: National Ocean Survey (NOS) IDB PID#:
SETTING CLASSIFICATION: Galvanized steel rod OPUS PID:
LATITUDE: 39° 32.4' N ( 39.54000) LONGITUDE: 74° 23.2' W ( -74.38670)
The primary bench mark is a disk located on the south end of Radio Road at the
shoreline of Great Bay, 69.34 m (227.5 ft) SE of wood utility pole #BT
173-P31631, 65.47 m (214.8 ft) SE of the centerline of Radio Road, 60.66 m
(199.0 ft) east of wood utility pole #ACE P32305, 20.24 m (66.4 ft) north of the
south end of the bulkhead, and 0.85 m (2.8 ft) west of the east face of the
bulkhead of Great Bay Marina. The bench mark is set 6 cm (0.2 ft) below ground
level, crimped to the top of a galvanized steel rod driven 15.2 m (50 ft), and
encased in a PVC pipe with concrete kickblock.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 2 of 5
Station ID: 8534244 PUBLICATION DATE: 05/01/2003
Name: GRAVELING POINT
NJ
NOAA Chart: 12316 Latitude: 39° 32.4' N ( 39.54000)
USGS Quad: NEW GRETNA Longitude: 74° 23.2' W ( -74.38670)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 4244 B 1977
DESIGNATION: 853 4244 B TIDAL
MONUMENTATION: Tidal Station disk VM#: 2661
AGENCY: National Ocean Survey (NOS) IDB PID#:
SETTING CLASSIFICATION: Concrete flagpole base OPUS PID:
LATITUDE: 39° 32.4' N ( 39.54000) LONGITUDE: 74° 23.2' W ( -74.38670)
The bench mark is a disk set in the top of the concrete base of the flagpole at
the Great Bay Marina, 122 m (400 ft) NE of bench mark 4244 A 1977, 19.05 m (62.5
ft) west of the SW corner of the 2-story wood marina building, 8.75 m (28.7 ft)
south of a gasoline station sign, 5.24 m (17.2 ft) north of the south face of
the wood bulkhead, 1.16 m (3.8 ft) north of the SW corner of the concrete base,
0.24 m (0.8 ft) SW of the flagpole, and 0.15 m (0.5 ft) above ground level.
BENCH MARK STAMPING: 4244 C 1977
DESIGNATION: 853 4244 C TIDAL
MONUMENTATION: Tidal Station disk VM#: 2662
AGENCY: National Ocean Survey (NOS) IDB PID#:
SETTING CLASSIFICATION: Galvanized steel rod OPUS PID:
LATITUDE: 39° 32.4' N ( 39.54000) LONGITUDE: 74° 23.2' W ( -74.38670)
The bench mark is a disk located at the entrance to the Great Bay Marina, 98 m
(320 ft) NW of bench mark 4244 B 1977, 9.30 m (30.5 ft) SE of the centerline of
Radio Road, 8.96 m (29.4 ft) north of the centerline of the entrance to the
marina, 4.85 m (15.9 ft) SE of wood utility pole #BT 172 P31630, and 2.74 m (9.0
ft) NE of a stop sign. The bench mark is crimped to the top of a galvanized
steel rod driven 15.2 m (50 ft), and encased in a PVC pipe with concrete
kickblock.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 3 of 5
Station ID: 8534244 PUBLICATION DATE: 05/01/2003
Name: GRAVELING POINT
NJ
NOAA Chart: 12316 Latitude: 39° 32.4' N ( 39.54000)
USGS Quad: NEW GRETNA Longitude: 74° 23.2' W ( -74.38670)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 4244 D 1977
DESIGNATION: 853 4244 D TIDAL
MONUMENTATION: Tidal Station disk VM#: 2663
AGENCY: National Ocean Survey (NOS) IDB PID#:
SETTING CLASSIFICATION: Galvanized steel rod OPUS PID:
LATITUDE: 39° 32.4' N ( 39.54000) LONGITUDE: 74° 23.2' W ( -74.38670)
The bench mark is a disk located on the south end of Radio Road at the north
shoreline of Great Bay, 98.24 m (322.3 ft) north of bench mark 4244 C 1977, 5.91
m (19.4 ft) east of the centerline of Radio Road, 4.08 m (13.4 ft) NW of the guy
wire anchor post supporting the wood utility pole described, and 1.01 m (3.3 ft)
east of wood utility pole #BT L401 170. The bench mark is set 6 cm (0.2 ft)
below ground level, crimped to the top of a galvanized steel rod driven 15.2 m
(50 ft), and encased in a PVC pipe with concrete kickblock.
BENCH MARK STAMPING: 4244 E 1977
DESIGNATION: 853 4244 E TIDAL
MONUMENTATION: Tidal Station disk VM#: 2664
AGENCY: National Ocean Survey (NOS) IDB PID#:
SETTING CLASSIFICATION: Galvanized steel rod OPUS PID:
LATITUDE: 39° 32.4' N ( 39.54000) LONGITUDE: 74° 23.2' W ( -74.38670)
The bench mark is a disk located on the south end of Radio Road at the north
shoreline of Great Bay, 102 m (336 ft) north of bench mark 4244 D 1977, 58.19 m
(190.9 ft) north of wood utility pole #BT-169- P31628, 6.00 m (19.7 ft) east of
the centerline of Radio Road, and 2.74 m (9.0 ft) south of wood utility pole #BT
168 P31627. The bench mark is set 6 cm (0.2 ft) below ground level, crimped to
the top of a galvanized steel rod driven 15.2 m (50 ft), and encased in a PVC
pipe with concrete kickblock.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 4 of 5
Station ID: 8534244 PUBLICATION DATE: 05/01/2003
Name: GRAVELING POINT
NJ
NOAA Chart: 12316 Latitude: 39° 32.4' N ( 39.54000)
USGS Quad: NEW GRETNA Longitude: 74° 23.2' W ( -74.38670)
T I D A L D A T U M S
Tidal datums at GRAVELING POINT based on:
LENGTH OF SERIES: 1 Year
TIME PERIOD: December 1977 - November 1978
TIDAL EPOCH: 1983-2001
CONTROL TIDE STATION: 8557380 LEWES, FT. MILES
Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in METERS:
HIGHEST OBSERVED WATER LEVEL (10/14/1977) = 1.934
MEAN HIGHER HIGH WATER MHHW = 1.117
MEAN HIGH WATER MHW = 1.009
MEAN TIDE LEVEL MTL = 0.524
MEAN SEA LEVEL MSL = 0.516
MEAN LOW WATER MLW = 0.039
MEAN LOWER LOW WATER MLLW = 0.000
LOWEST OBSERVED WATER LEVEL (12/10/1977) = -0.733
North American Vertical Datum (NAVD88)
Bench Mark Elevation Information In METERS above:
Stamping or Designation MLLW MHW
4244 A 1977 1.812 0.803
4244 B 1977 2.334 1.325
4244 C 1977 1.873 0.864
4244 D 1977 2.154 1.145
4244 E 1977 1.606 0.597
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 5 of 5
Station ID: 8534244 PUBLICATION DATE: 05/01/2003
Name: GRAVELING POINT
NJ
NOAA Chart: 12316 Latitude: 39° 32.4' N ( 39.54000)
USGS Quad: NEW GRETNA Longitude: 74° 23.2' W ( -74.38670)
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 NGS's Integrated Data Base (IDB PID)
provides geodetic datum based on traditionally leveled and bluebooked ties to
the National Spatial Reference System(NSRS) https://www.ngs.noaa.gov/datasheets/.
The NGS Online Positioning User Service (OPUS PID) provides geodetic datum based
on GPS position & tie it to the NSRS https://www.ngs.noaa.gov/OPUS/.
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.