U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Datums Page Page 1 of 4
PUBLICATION DATE: 02/10/1992
Station ID: 8453572 SUPERCEDED DATE: 04/21/2003
Name: WARWICK POINT, NARRAGANSETT BAY
RHODE ISLAND
NOAA Chart: 13224 Latitude: 41° 40.0' N
USGS Quad: EAST GREENWICH Longitude: 71° 22.7' W
To reach the tidal bench marks from the intersection of Interstate Highways 95
and 195 in Providence, proceed south on Interstate Highway 95 for 9 miles (14
km) to State Route 117, go east on State Route 117 to Warwick Neck Avenue, turn
south onto Warwick Neck Avenue and continue until the road ends at Warwick Coast
Guard Light Station. The bench marks are in the sea wall along the south shore,
at the entrance to the Coast Guard com- pound, and at the lightkeeper's garage.
The tide gauge sensor was just SE of the lighthouse and the staff was on the
rock jetty.
T I D A L B E N C H M A R K S
PRIMARY BENCH MARK STAMPING: 3572 F 1983
MONUMENTATION: Survey Disk VM#: 2179
AGENCY: PID:
SETTING CLASSIFICATION: Concrete Storm Drain
The primary bench mark is set flush in the SE corner of a concrete storm drain
on the west side of Warwick Neck Avenue at the entrance to the Coast Guard Light
Station, 21.2 feet (6.5 m) west of the centerline of the drive to the
lighthouse, 11.2 feet (3.4 m) east of a chainlink fence along the east edge of a
private residence, 5.2 feet (1.6 m) north of a chainlink fence along the north
edge of the Coast Guard property, and 3.3 feet (1.0 m) south of the south edge
of asphalt.
BENCH MARK STAMPING: 3572 G 1983
MONUMENTATION: Survey Disk VM#: 2180
AGENCY: PID:
SETTING CLASSIFICATION: Concrete Foundation
The bench mark is set flush in the NW corner of a concrete garage foundation at
the Coast Guard Light Station, 39.4 feet (12.0 m) SW of the NW corner of the
lightkeeper's house porch, 8.4 feet (2.6 m) south of the south post of a
basketball hoop, 5.8 feet (1.8 m) east of a chainlink fence, and 0.6 foot (0.2
m) north of the NW garage corner.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 2 of 4
PUBLICATION DATE: 02/10/1992
Station ID: 8453572 SUPERCEDED DATE: 04/21/2003
Name: WARWICK POINT, NARRAGANSETT BAY
RHODE ISLAND
NOAA Chart: 13224 Latitude: 41° 40.0' N
USGS Quad: EAST GREENWICH Longitude: 71° 22.7' W
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 3572 H 1983
MONUMENTATION: Survey Disk VM#: 2181
AGENCY: PID:
SETTING CLASSIFICATION: Concrete Sea Wall
The bench mark is set in the top of a concrete seawall along the south shore of
the Coast Guard Light Station, 124.7 feet (38.0 m) SE of the lighthouse base,
and 101.8 feet (31.0 m) east of Bench Mark 3572 K 1983.
BENCH MARK STAMPING: 3572 J 1983
MONUMENTATION: Survey Disk VM#: 2182
AGENCY: PID:
SETTING CLASSIFICATION: Concrete Sea Wall
The bench mark is set in the top of a concrete sea wall along the south shore of
the Coast Guard Light Station, 173.9 feet (53.0 m) SE of the lighthouse base,
and 108.2 feet (33.0 m) east of Bench Mark 3572 H 1983.
BENCH MARK STAMPING: 3572 K 1983
MONUMENTATION: Survey Disk VM#: 2183
AGENCY: PID:
SETTING CLASSIFICATION: Concrete Sea Wall
The bench mark is set in the SW corner of the concrete seawall along the south
shore of the Coast Guard Light Station, 253 feet (77 m) west of the SE end of
the rock jetty, and 134.4 feet (41.0 m) south of the lighthouse base.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 3 of 4
PUBLICATION DATE: 02/10/1992
Station ID: 8453572 SUPERCEDED DATE: 04/21/2003
Name: WARWICK POINT, NARRAGANSETT BAY
RHODE ISLAND
NOAA Chart: 13224 Latitude: 41° 40.0' N
USGS Quad: EAST GREENWICH Longitude: 71° 22.7' W
T I D A L D A T U M S
Tidal datums at WARWICK POINT, NARRAGANSETT BAY based on:
LENGTH OF SERIES: 1 MONTH
TIME PERIOD: OCTOBER 1977
TIDAL EPOCH: 1960-1978
CONTROL TIDE STATION: 8454000 PROVIDENCE
Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in FEET:
HIGHEST OBSERVED WATER LEVEL (11/11/1977) = 6.43
MEAN HIGHER HIGH WATER MHHW = 4.44
MEAN HIGH WATER MHW = 4.17
MEAN TIDE LEVEL MTL = 2.16
MEAN LOW WATER MLW = 0.15
MEAN LOWER LOW WATER MLLW = 0.00
LOWEST OBSERVED WATER LEVEL (09/15/1977) = -1.02
Bench Mark Elevation Information In FEET above:
Stamping or Designation MLLW MHW
3572 F 1983 40.76 36.59
3572 G 1983 34.51 30.34
3572 H 1983 10.48 6.31
3572 J 1983 10.29 6.12
3572 K 1983 10.51 6.34
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 4 of 4
PUBLICATION DATE: 02/10/1992
Station ID: 8453572 SUPERCEDED DATE: 04/21/2003
Name: WARWICK POINT, NARRAGANSETT BAY
RHODE ISLAND
NOAA Chart: 13224 Latitude: 41° 40.0' N
USGS Quad: EAST GREENWICH Longitude: 71° 22.7' 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.