U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Datums Page Page 1 of 5 Station ID: 8447495 PUBLICATION DATE: 04/21/2003 Name: SAQUATUCKET HARBOR MA NOAA Chart: 13246 Latitude: 41° 40.1' N ( 41.66830) USGS Quad: HARWICH Longitude: 70° 3.4' W ( -70.05670) To reach the tidal bench marks from the intersection of Route 6 and 134 in South Dennis, proceed south on Route 134 for 3.7 km (2.3 mi) to Route 28, then east on Route 28 for 8.0 km (5.0 mi) to Saquatucket Harbor. The bench marks are in the vicinity of the harbor parking lot, and the tide gauge and staff were attached to floating dock pilings south of the Harbormaster's office. T I D A L B E N C H M A R K S PRIMARY BENCH MARK STAMPING: 7495 A 1993 DESIGNATION: 844 7495 A MONUMENTATION: Tidal Station disk VM#: 12472 AGENCY: National Ocean Service (NOS) IDB PID#: SETTING CLASSIFICATION: Concrete sea wall OPUS PID: LATITUDE: 41° 40.1' N ( 41.66830) LONGITUDE: 70° 3.4' W ( -70.05670) The primary bench mark is a disk set in the concrete seawall cap of Saquatucket Harbor, 20.70 m (67.9 ft) east of the western corner of the sea wall, 7.92 m (26.0 ft) SW of the NW corner of a small utility building, and 5.49 m (18.0 ft) SW of the centerline of the small road fronting the harbor.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 2 of 5 Station ID: 8447495 PUBLICATION DATE: 04/21/2003 Name: SAQUATUCKET HARBOR MA NOAA Chart: 13246 Latitude: 41° 40.1' N ( 41.66830) USGS Quad: HARWICH Longitude: 70° 3.4' W ( -70.05670) T I D A L B E N C H M A R K S BENCH MARK STAMPING: 7495 B 1993 DESIGNATION: 844 7495 B MONUMENTATION: Tidal Station disk VM#: 12473 AGENCY: National Ocean Service (NOS) IDB PID#: SETTING CLASSIFICATION: Concrete wing wall OPUS PID: LATITUDE: 41° 40.1' N ( 41.66830) LONGITUDE: 70° 3.4' W ( -70.05670) The bench mark is a disk set in the dogleg corner of the concrete wingwall on the east side of Brax Landing Restaurant, 29.41 m (96.5 ft) north of the westernmost group of piles at the entrance to the road fronting Saquatucket Harbor, 13.87 m (45.5 ft) WSW of the edge of the Saquatucket Harbor parking lot, 10.21 m (33.5 ft) SE of the NE corner of Brax Landing, and 1.37 m (4.5 ft) above grade. BENCH MARK STAMPING: 7495 C 1993 DESIGNATION: 844 7495 C MONUMENTATION: Tidal Station disk VM#: 12474 AGENCY: National Ocean Service (NOS) IDB PID#: SETTING CLASSIFICATION: Concrete foundation OPUS PID: LATITUDE: 41° 40.1' N ( 41.66830) LONGITUDE: 70° 3.4' W ( -70.05670) The bench mark is a disk set in the southern edge of the 1 m (2 ft) diameter concrete flagpole base at Thompsons Farm Market (710 Route 28), 24.38 m (80.0 ft) NE of telephone pole No. 81, 22.40 m (73.5 ft) SW of the SW corner of the market, and 9.94 m (32.6 ft) NNW of the centerline of Route 28.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 3 of 5 Station ID: 8447495 PUBLICATION DATE: 04/21/2003 Name: SAQUATUCKET HARBOR MA NOAA Chart: 13246 Latitude: 41° 40.1' N ( 41.66830) USGS Quad: HARWICH Longitude: 70° 3.4' W ( -70.05670) T I D A L B E N C H M A R K S BENCH MARK STAMPING: 7495 D 1993 DESIGNATION: 844 7495 D MONUMENTATION: Tidal Station disk VM#: 12475 AGENCY: National Ocean Service (NOS) IDB PID#: SETTING CLASSIFICATION: Concrete head wall OPUS PID: LATITUDE: 41° 40.1' N ( 41.66830) LONGITUDE: 70° 3.4' W ( -70.05670) The bench mark is a disk set in the western end of the lower tier of a concrete headwall over the small stream just west of Saquatucket Harbor and on the south side of Route 28, 11.37 m (37.3 ft) SSW of telephone pole No. 79, 8.99 m (29.5 ft) SSE of the centerline of Route 28, 0.46 m (1.5 ft) ENE of the western end of the lower end of the headwall, and 2 m (6 ft) below the surface of the road. BENCH MARK STAMPING: TBM SLAB 1993 DESIGNATION: 844 7495 TBM SLAB MONUMENTATION: Survey disk VM#: 12476 AGENCY: US Army Corps of Engineers (USE) IDB PID#: SETTING CLASSIFICATION: Concrete foundation OPUS PID: LATITUDE: 41° 40.1' N ( 41.66830) LONGITUDE: 70° 3.4' W ( -70.05670) The bench mark is a disk set in the SW corner of a concrete pad supporting a large green utility box adjacent to the harbormasters building, 15.24 m (50.0 ft) ENE of a large flagpole, 15.24 m (50.0 ft) NE of the seawall, and 5.88 m (19.3 ft) SSE of the SE corner of the harbormaster building.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 4 of 5 Station ID: 8447495 PUBLICATION DATE: 04/21/2003 Name: SAQUATUCKET HARBOR MA NOAA Chart: 13246 Latitude: 41° 40.1' N ( 41.66830) USGS Quad: HARWICH Longitude: 70° 3.4' W ( -70.05670) T I D A L D A T U M S Tidal datums at SAQUATUCKET HARBOR based on: LENGTH OF SERIES: 5 Months TIME PERIOD: May 1993 - September 1993 TIDAL EPOCH: 1983-2001 CONTROL TIDE STATION: 8449130 NANTUCKET ISLAND, NANTUCKET SOUND Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in METERS: MEAN HIGHER HIGH WATER MHHW = 1.325 MEAN HIGH WATER MHW = 1.220 North American Vertical Datum NAVD88 = 0.788 MEAN SEA LEVEL MSL = 0.682 MEAN TIDE LEVEL MTL = 0.652 MEAN LOW WATER MLW = 0.085 MEAN LOWER LOW WATER MLLW = 0.000 North American Vertical Datum (NAVD88) Bench Mark Elevation Information In METERS above: Stamping or Designation MLLW MHW 7495 A 1993 2.334 1.114 7495 B 1993 4.502 3.282 7495 C 1993 3.780 2.560 7495 D 1993 2.186 0.966 TBM SLAB 1993 3.330 2.110
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 5 of 5 Station ID: 8447495 PUBLICATION DATE: 04/21/2003 Name: SAQUATUCKET HARBOR MA NOAA Chart: 13246 Latitude: 41° 40.1' N ( 41.66830) USGS Quad: HARWICH Longitude: 70° 3.4' W ( -70.05670) 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.