U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Datums Page Page 1 of 5
Station ID: 8450948 PUBLICATION DATE: 06/16/2004
Name: ANTHONY POINT
RI
NOAA Chart: 13221 Latitude: 41° 38.3' N ( 41.63830)
USGS Quad: TIVERTON Longitude: 71° 12.7' W ( -71.21170)
To reach the tidal bench marks from Newport, travel north on State Route 114 to
State Route 138, then proceed north and east towards Tiverton on State Route
138, passing over a bridge, then take the first right towards Tiverton, Little
Compton on State Road 77/177, and make a sharp 270 degree turn at the first
right onto Riverside Avenue, then continue to Riverside Marina Inc. at 211
Riverside Avenue. The bench marks are located on the west side of Riverside
Avenue between the Tiverton Bridge and the railroad bridge. The tide gage and
staff were located on the pier at Riverside Marina.
T I D A L B E N C H M A R K S
PRIMARY BENCH MARK STAMPING: NO 6 1931
DESIGNATION: 845 0948 TIDAL 6
MONUMENTATION: Tidal Station disk VM#: 2128
AGENCY: US Coast & Geodetic Survey
(USC&GS) IDB PID#:
SETTING CLASSIFICATION: Concrete abutment OPUS PID:
LATITUDE: 41° 38.3' N ( 41.63830) LONGITUDE: 71° 12.7' W ( -71.21170)
The primary bench mark is a disk set flush in the south side of east granite
abutment of the New York, New Haven and Hartford Railroad bridge across Sakonnet
River, and 0.76 m (2.5 ft) below railroad track level.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 2 of 5
Station ID: 8450948 PUBLICATION DATE: 06/16/2004
Name: ANTHONY POINT
RI
NOAA Chart: 13221 Latitude: 41° 38.3' N ( 41.63830)
USGS Quad: TIVERTON Longitude: 71° 12.7' W ( -71.21170)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 0948 B 1977
DESIGNATION: 845 0948 B TIDAL
MONUMENTATION: Tidal Station disk VM#: 2129
AGENCY: National Ocean Survey (NOS) IDB PID#:
SETTING CLASSIFICATION: Concrete block OPUS PID:
LATITUDE: 41° 38.3' N ( 41.63830) LONGITUDE: 71° 12.7' W ( -71.21170)
The bench mark is a disk set flush in a 1 x 1 m (3 x 2 ft) concrete block, 27 m
(90 ft) east of a power cable support tower, 2 m (8 ft) south of the centerline
of the railroad tracks, and on the south foot path along the railroad tracks.
BENCH MARK STAMPING: 0948 C 1977
DESIGNATION: 845 0948 C TIDAL
MONUMENTATION: Tidal Station disk VM#: 2130
AGENCY: National Ocean Survey (NOS) IDB PID#:
SETTING CLASSIFICATION: Concrete boat ramp OPUS PID#: BBDJ01
LATITUDE: 41° 38.3' N ( 41.63830) LONGITUDE: 71° 12.7' W ( -71.21170)
The bench mark is a disk set flush in the south end of the concrete boat ramp at
Riverside Marina Inc., 17 m (57 ft) SW of the SW corner of the store at 211
Riverside Avenue, and 3 m (11 ft) west of the shoreline.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 3 of 5
Station ID: 8450948 PUBLICATION DATE: 06/16/2004
Name: ANTHONY POINT
RI
NOAA Chart: 13221 Latitude: 41° 38.3' N ( 41.63830)
USGS Quad: TIVERTON Longitude: 71° 12.7' W ( -71.21170)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 0948 D 1977
DESIGNATION: 845 0948 D TIDAL
MONUMENTATION: Tidal Station disk VM#: 2131
AGENCY: National Ocean Survey (NOS) IDB PID#:
SETTING CLASSIFICATION: Pavement OPUS PID:
LATITUDE: 41° 38.3' N ( 41.63830) LONGITUDE: 71° 12.7' W ( -71.21170)
The bench mark is a disk set flush in concrete at the SE corner of the store
front located at 211 Riverside Avenue, 28 m (93 ft) south of the railroad
overpass, 14 m (45 ft) west of the centerline of Riverside Avenue, and 6 m (19
ft) north of the dirt road leading to the pier.
BENCH MARK STAMPING: 0948 E 1977
DESIGNATION: 845 0948 E TIDAL
MONUMENTATION: Tidal Station disk VM#: 2132
AGENCY: National Ocean Survey (NOS) IDB PID#:
SETTING CLASSIFICATION: Concrete support OPUS PID:
LATITUDE: 41° 38.3' N ( 41.63830) LONGITUDE: 71° 12.7' W ( -71.21170)
The bench mark is a disk set flush in concrete in the north most support of the
Tiverton Bridge, 7 m (23 ft) west of the centerline of Riverside Avenue and 5 m
(18 ft) east of the shoreline.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 4 of 5
Station ID: 8450948 PUBLICATION DATE: 06/16/2004
Name: ANTHONY POINT
RI
NOAA Chart: 13221 Latitude: 41° 38.3' N ( 41.63830)
USGS Quad: TIVERTON Longitude: 71° 12.7' W ( -71.21170)
T I D A L D A T U M S
Tidal datums at ANTHONY POINT based on:
LENGTH OF SERIES: 1 MONTH
TIME PERIOD: October 1977
TIDAL EPOCH: 1983-2001
CONTROL TIDE STATION: 8454000 PROVIDENCE, PROVIDENCE RIVER
Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in METERS:
MEAN HIGHER HIGH WATER MHHW = 1.280
MEAN HIGH WATER MHW = 1.198
MEAN TIDE LEVEL MTL = 0.626
MEAN SEA LEVEL MSL = 0.581
MEAN LOW WATER MLW = 0.054
MEAN LOWER LOW WATER MLLW = 0.000
North American Vertical Datum (NAVD88)
Bench Mark Elevation Information In METERS above:
Stamping or Designation MLLW MHW
NO 6 1931 4.958 3.760
0948 B 1977 5.712 4.514
0948 C 1977 2.067 0.869
0948 D 1977 2.491 1.293
0948 E 1977 2.828 1.630
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 5 of 5
Station ID: 8450948 PUBLICATION DATE: 06/16/2004
Name: ANTHONY POINT
RI
NOAA Chart: 13221 Latitude: 41° 38.3' N ( 41.63830)
USGS Quad: TIVERTON Longitude: 71° 12.7' W ( -71.21170)
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.