U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Datums Page Page 1 of 4
PUBLICATION DATE: 11/19/1985
Station ID: 8454658 SUPERCEDED DATE: 04/21/2003
Name: NARRAGANSETT PIER, NARRAGANSETT BAY
RHODE ISLAND
NOAA Chart: 13221 Latitude: 41° 25.3' N
USGS Quad: NARRAGANSETT BAY Longitude: 71° 27.3' W
To reach the tidal bench marks which are located in the Town of Narragansett,
Washington County, Rhode Island, proceed to State Pier #5, located at the
intersection of Ocean Road and South Pier Road. The bench marks are located in
the vicinity of State Pier #5 and extend east along the seawall and curb of
Ocean Road. The gage and staff were located midway on the northside of State
Pier #5.
T I D A L B E N C H M A R K S
PRIMARY BENCH MARK STAMPING: 4658 E 1977
MONUMENTATION: Survey Disk VM#: 2209
AGENCY: PID:
SETTING CLASSIFICATION: Concrete Pier Deck
The bench mark is set flush in the concrete pier deck of State Pier #5 at the NW
end of the pier, 244.1 feet (74.4 m) SE (150 ) of Bench Mark NO 2 1956, 6.7 feet
(2.0 m) south of the north face of the pier, and 1.7 feet (0.5 m) east of the
lower corner of the east side of the westernmost steps leading down to the pier
deck.
BENCH MARK STAMPING: NO 2 1956
MONUMENTATION: Survey Disk VM#: 2205
AGENCY: PID:
SETTING CLASSIFICATION: Concrete Seawall
The bench mark is set flush in top of a 1.5 foot (0.5 m) wide granite railing on
a concrete seawall, 244.1 feet (74.4 m) north of Bench Mark 4658 E 1977, 154.5
feet (47.1 m) SSW of Bench Mark 4658 D 1977, 60 feet (18 m) east of a stone
structure fountain at the intersection of Ocean Road and South Pier Road, 45
feet (14 m) south of the centerline of South Pier Road, and 4 feet (1 m) north
of the south end of the granite railing on the concrete seawall.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 2 of 4
PUBLICATION DATE: 11/19/1985
Station ID: 8454658 SUPERCEDED DATE: 04/21/2003
Name: NARRAGANSETT PIER, NARRAGANSETT BAY
RHODE ISLAND
NOAA Chart: 13221 Latitude: 41° 25.3' N
USGS Quad: NARRAGANSETT BAY Longitude: 71° 27.3' W
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 4658 B 1977
MONUMENTATION: Survey Disk VM#: 2206
AGENCY: PID:
SETTING CLASSIFICATION: Concrete Seawall
The bench mark is set flush in top of a concrete seawall running east along the
south side of Ocean Road, 439 feet (134 m) SSW of the center of the intersection
of Ocean Road and Congdon Road, 140.5 feet (42.8 m) NE (20 ) of Bench Mark 4658
C 1977, and 28.5 feet (9 m) SE of the centerline of Ocean Road.
BENCH MARK STAMPING: 4658 C 1977
MONUMENTATION: Survey Disk VM#: 2207
AGENCY: PID:
SETTING CLASSIFICATION: Concrete Seawall
The bench mark is set flush in top of a concrete seawall running east along the
south side of Ocean Road, 140.5 feet (42.8 m) SW (200 ) of Bench Mark 4658 B
1977, 116.3 feet (35.4 m) NE (40 ) of Bench Mark 4658 D 1977, and 29 feet (9 m)
SE of the centerline of Ocean Road.
BENCH MARK STAMPING: 4658 D 1977
MONUMENTATION: Survey Disk VM#: 2208
AGENCY: PID:
SETTING CLASSIFICATION: Concrete Curb
The bench mark is set flush in the curb on the west side of Ocean Road, 154.2
feet (47.0 m) NNE (20 ) of Bench Mark NO 2 1956, 116.3 feet (35.4 m) SW (200 )
of Bench Mark 4658 C 1977, 70 feet (21 m) NNE (20 ) of the intersection of South
Pier Road and Ocean Road, 20.1 feet (6.1 m) NNE of a centerline of the steps and
sidewalk on the east side of the Green Inn Motor Hotel, and 9 feet (3 m) east of
the stone wall surrounding the Green Inn Motor Hotel.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 3 of 4
PUBLICATION DATE: 11/19/1985
Station ID: 8454658 SUPERCEDED DATE: 04/21/2003
Name: NARRAGANSETT PIER, NARRAGANSETT BAY
RHODE ISLAND
NOAA Chart: 13221 Latitude: 41° 25.3' N
USGS Quad: NARRAGANSETT BAY Longitude: 71° 27.3' W
T I D A L D A T U M S
Tidal datums at NARRAGANSETT PIER, NARRAGANSETT BAY based on:
LENGTH OF SERIES: 3 MONTHS
TIME PERIOD: AUGUST-OCTOBER 1977
TIDAL EPOCH: 1960-1978
CONTROL TIDE STATION: 8452660 NEWPORT
Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in FEET:
HIGHEST OBSERVED WATER LEVEL (10/15/1977) = 5.70
MEAN HIGHER HIGH WATER MHHW = 3.64
MEAN HIGH WATER MHW = 3.38
MEAN TIDE LEVEL MTL = 1.75
MEAN LOW WATER MLW = 0.13
MEAN LOWER LOW WATER MLLW = 0.00
LOWEST OBSERVED WATER LEVEL (10/17/1977) = -1.20
Bench Mark Elevation Information In FEET above:
Stamping or Designation MLLW MHW
4658 E 1977 7.81 4.43
NO 2 1956 21.90 18.52
4658 B 1977 17.58 14.20
4658 C 1977 18.64 15.26
4658 D 1977 17.12 13.74
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 4 of 4
PUBLICATION DATE: 11/19/1985
Station ID: 8454658 SUPERCEDED DATE: 04/21/2003
Name: NARRAGANSETT PIER, NARRAGANSETT BAY
RHODE ISLAND
NOAA Chart: 13221 Latitude: 41° 25.3' N
USGS Quad: NARRAGANSETT BAY Longitude: 71° 27.3' 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.