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Administration National Ocean Service Datums Page Page 1 of 4 PUBLICATION DATE: 11/19/1985 Station ID: 8454658 SUPERCEDED DATE: 04/21/2003 Name: NARRAGANSETT PIER, NARRAGANSETT BAY RHODE ISLAND NOAA Chart: 13221 Latitude: 41° 25.3' N USGS Quad: NARRAGANSETT BAY Longitude: 71°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and Atmospheric Administration National Ocean Service Page 2 of 4 PUBLICATION DATE: 11/19/1985 Station ID: 8454658 SUPERCEDED DATE: 04/21/2003 Name: NARRAGANSETT PIER, NARRAGANSETT BAY RHODE ISLAND NOAA Chart: 13221 Latitude: 41° 25.3' N USGS Quad: NARRAGANSETT BAY Longitude: 71°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.