U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Datums Page Page 1 of 6 Station ID: 8445138 PUBLICATION DATE: 02/05/2004 Name: SCITUATE, SCITUATE HARBOR MA NOAA Chart: 13269 Latitude: 42° 12.1' N ( 42.20170) USGS Quad: SCITUATE Longitude: 70° 43.6' W ( -70.72670) To reach the tidal bench marks from the intersection of State Routes 3 and 14 (Exit 11 on State Route 3), proceed east on State Route 14 for 1.0 km (0.6 mi) to State Route 139, then continue west on State Route 139 for 1.8 km (1.1 mi) to State Route 3A, then turn left and proceed north on State Route 3A for 15.4 km (9.6 mi) to First Parish Road, then turn right and proceed east on First Parish Road for 4.0 km (2.5 mi) to Front Street, then turn left and proceed NE on Front Street for 0.6 km (0.4 mi) to Jericho Road, continue north on Jericho Road for 0.5 km (0.3 mi) to Scituate Harbor Marina. The bench marks are near the marina and along Front Street and Jericho Road. The tide gage and staff were on the east end of the marina pier. T I D A L B E N C H M A R K S PRIMARY BENCH MARK STAMPING: 5138 A 1990 DESIGNATION: 844 5138 A MONUMENTATION: Tidal Station disk VM#: 1467 AGENCY: National Ocean Service (NOS) IDB PID#: SETTING CLASSIFICATION: Concrete sea wall OPUS PID#: BBBJ43 LATITUDE: 42° 12.1' N ( 42.20170) LONGITUDE: 70° 43.6' W ( -70.72670) The primary bench mark is a disk set in the bend of the concrete sea wall located in the NE corner of the Scituate Harbor Marina parking lot, 37.31 m (122.4 ft) SW of the NE corner of the west end of the sea wall, 21.52 m (70.6 ft) north of utility pole #11B, 0.30 m (1.0 ft) NW of the SE corner of the sea wall, and 0.37 m (1.2 ft) above the parking lot.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 2 of 6 Station ID: 8445138 PUBLICATION DATE: 02/05/2004 Name: SCITUATE, SCITUATE HARBOR MA NOAA Chart: 13269 Latitude: 42° 12.1' N ( 42.20170) USGS Quad: SCITUATE Longitude: 70° 43.6' W ( -70.72670) T I D A L B E N C H M A R K S BENCH MARK STAMPING: GATE 1924 DESIGNATION: GATE ALIAS: 4 USE MONUMENTATION: Bench Mark disk VM#: 1468 AGENCY: US Army Corps of Engineers (USE) IDB PID#: SETTING CLASSIFICATION: Rock wall OPUS PID: LATITUDE: 42° 12.1' N ( 42.20170) LONGITUDE: 70° 43.6' W ( -70.72670) The bench mark is a disk set in a rock wall east of 8 Beaver Dam Road, 25 m (83 ft) north of the NW corner of 4 Beaver Dam Road, 23 m (74 ft) east of the SE porch corner of 8 Beaver Dam Road, and 1.86 m (6.1 ft) west of a wooden light pole at the inshore end of a pier. BENCH MARK STAMPING: NO 7 1952 DESIGNATION: 844 5138 TIDAL 7 MONUMENTATION: Tidal Station disk VM#: 1469 AGENCY: US Coast and Geodetic Survey (USC&GS) IDB PID#: SETTING CLASSIFICATION: Concrete sea wall OPUS PID: LATITUDE: 42° 12.1' N ( 42.20170) LONGITUDE: 70° 43.6' W ( -70.72670) The bench mark is a disk set in the sea wall located on the east side of Front Street and south of the entrance to the marina pier, 8.26 m (27.1 ft) SSE of a power pole, 6.25 m (20.5 ft) east of the centerline of Front Street, 0.15 m (0.5 ft) west of the edge of the sea wall, and 0.64 m (2.1 ft) below the level of the sidewalk.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 3 of 6 Station ID: 8445138 PUBLICATION DATE: 02/05/2004 Name: SCITUATE, SCITUATE HARBOR MA NOAA Chart: 13269 Latitude: 42° 12.1' N ( 42.20170) USGS Quad: SCITUATE Longitude: 70° 43.6' W ( -70.72670) T I D A L B E N C H M A R K S BENCH MARK STAMPING: 5138 B 1990 DESIGNATION: 844 5138 B MONUMENTATION: Tidal Station disk VM#: 1470 AGENCY: National Ocean Service (NOS) IDB PID#: SETTING CLASSIFICATION: Concrete foundation OPUS PID: LATITUDE: 42° 12.1' N ( 42.20170) LONGITUDE: 70° 43.6' W ( -70.72670) The bench mark is a disk set in a concrete foundation located at the west end of the Scituate Harbor Boat Club pier, 20.12 m (66.0 ft) SW of the flagpole at the boat club, 10.30 m (33.8 ft) south of the SE corner of the boat club building, 0.91 m (3.0 ft) NE of the SW corner of the foundation, and 0.30 m (1.0 ft) above ground level.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 4 of 6 Station ID: 8445138 PUBLICATION DATE: 02/05/2004 Name: SCITUATE, SCITUATE HARBOR MA NOAA Chart: 13269 Latitude: 42° 12.1' N ( 42.20170) USGS Quad: SCITUATE Longitude: 70° 43.6' W ( -70.72670) T I D A L B E N C H M A R K S BENCH MARK STAMPING: DESIGNATION: 844 5138 BM 4 ALIAS: NO STAMPING 1 (4 1924) MONUMENTATION: Bench Mark disk VM#: 1471 AGENCY: US Coast and Geodetic Survey (USC&GS) IDB PID#: SETTING CLASSIFICATION: Rock wall OPUS PID: LATITUDE: 42° 12.1' N ( 42.20170) LONGITUDE: 70° 43.6' W ( -70.72670) The bench mark is a disk set in a rock wall located NNE of 8 Beaver Dam Road, 31 m (101 ft) NW of bench mark GATE 1924, 20.57 m (67.5 ft) south of a chain link fence, and 15.64 m (51.3 ft) NNE of the NE porch corner of 8 Beaver Dam Road.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 5 of 6 Station ID: 8445138 PUBLICATION DATE: 02/05/2004 Name: SCITUATE, SCITUATE HARBOR MA NOAA Chart: 13269 Latitude: 42° 12.1' N ( 42.20170) USGS Quad: SCITUATE Longitude: 70° 43.6' W ( -70.72670) T I D A L D A T U M S Tidal datums at SCITUATE, SCITUATE HARBOR based on: LENGTH OF SERIES: 3 MONTHS TIME PERIOD: June 1990 - August 1990 TIDAL EPOCH: 1983-2001 CONTROL TIDE STATION: 8443970 BOSTON, BOSTON HARBOR Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in METERS: MEAN HIGHER HIGH WATER MHHW = 2.970 MEAN HIGH WATER MHW = 2.834 MEAN SEA LEVEL MSL = 1.491 MEAN TIDE LEVEL MTL = 1.471 MEAN LOW WATER MLW = 0.108 MEAN LOWER LOW WATER MLLW = 0.000 North American Vertical Datum (NAVD88) Bench Mark Elevation Information In METERS above: Stamping or Designation MLLW MHW 5138 A 1990 4.708 1.874 GATE 1924 4.915 2.081 NO 7 1952 4.468 1.634 5138 B 1990 4.954 2.120 844 5138 BM 4 4.992 2.158
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 6 of 6 Station ID: 8445138 PUBLICATION DATE: 02/05/2004 Name: SCITUATE, SCITUATE HARBOR MA NOAA Chart: 13269 Latitude: 42° 12.1' N ( 42.20170) USGS Quad: SCITUATE Longitude: 70° 43.6' W ( -70.72670) 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.