U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Datums Page Page 1 of 6 Station ID: 8511236 PUBLICATION DATE: 02/08/2018 Name: PLUM ISLAND PLUM GUT HARBOR NY NOAA Chart: 13209 Latitude: 41° 10.3' N ( 41.17170) USGS Quad: PLUM ISLAND Longitude: 72° 12.3' W ( -72.20500) To reach the tidal bench marks from the intersection of State Roads 25 and 27 in Greenport Long Island, proceed east on State Road 25 for 12.9 km (8.0 mi), turn right into the USDA Animal Disease Centers facility, and take the Plum Island employee shuttle ferry to Plum Gut Harbor. The bench marks are within the confines of the fenced in Harbor area; access to restricted area beyond the guard house is not necessary. The tide gauge station and staff were in the NE portion of the harbor, on the short angled section of bulkhead. T I D A L B E N C H M A R K S
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 2 of 6 Station ID: 8511236 PUBLICATION DATE: 02/08/2018 Name: PLUM ISLAND PLUM GUT HARBOR NY NOAA Chart: 13209 Latitude: 41° 10.3' N ( 41.17170) USGS Quad: PLUM ISLAND Longitude: 72° 12.3' W ( -72.20500) T I D A L B E N C H M A R K S PRIMARY BENCH MARK STAMPING: DESIGNATION: TIDAL 4 STA II 24 ALIAS: 851 1236 NO STAMPING 1 MONUMENTATION: Rivet VM#: 2284 AGENCY: National Geodetic Survey (NGS) IDB PID#: LX0271 SETTING CLASSIFICATION: Concrete bulkhead OPUS PID: LATITUDE: 41° 10.3' N ( 41.17222) LONGITUDE: 72° 12.4' W ( -72.20639) The primary bench mark is a 3/8-inch monel rivet set in a concrete section of bulkhead on the west side of the harbor, 31.61 (103.7 ft) south of the NW corner of the bulkhead for the Plum Isle ferry, 28.10 m (92.2 ft) SE of the east corner of Feed Building, 17.68 m (58.0 ft) north of the center line of a wood pier, 1.10 m (3.6 ft) south of the north edge of the concrete bulkhead, and 0.21 m (0.7 ft) west of the east face of the concrete bulkhead. It was designated BM 4 1943 by USC&GS.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 3 of 6 Station ID: 8511236 PUBLICATION DATE: 02/08/2018 Name: PLUM ISLAND PLUM GUT HARBOR NY NOAA Chart: 13209 Latitude: 41° 10.3' N ( 41.17170) USGS Quad: PLUM ISLAND Longitude: 72° 12.3' W ( -72.20500) T I D A L B E N C H M A R K S BENCH MARK STAMPING: NO 7 1957 DESIGNATION: TIDAL 7 STA II 24 MONUMENTATION: Bench Mark disk VM#: 2280 AGENCY: National Geodetic Survey (NGS) IDB PID#: LX0268 SETTING CLASSIFICATION: Concrete base of pipeline OPUS PID: LATITUDE: 41° 10.4' N ( 41.17306) LONGITUDE: 72° 12.3' W ( -72.20472) The bench mark is a disk set flush in the top of the SW corner of the concrete base of a pipeline on the north side of the harbor, 41.15 m (135.0 ft) south of the intersection of the pipeline with the fence, 16.06 m (52.7 ft) north of a fire hydrant, 8.93 m (29.3 ft) west of a concrete retaining wall of the fuel bunker, and 1.07 m (3.5 ft) north of the pipeline support post just north of the road leading around the harbor. BENCH MARK STAMPING: NO 8 1961 DESIGNATION: 851 1236 TIDAL 8 MONUMENTATION: Bench Mark disk VM#: 2281 AGENCY: National Geodetic Survey (NGS) IDB PID#: SETTING CLASSIFICATION: Concrete sill OPUS PID: LATITUDE: 41° 10.4' N ( 41.17306) LONGITUDE: 72° 12.3' W ( -72.20472) The bench mark is a disk set flush in the NW end of the concrete sill of a garage door at the guard house at Plum Gut Harbor.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 4 of 6 Station ID: 8511236 PUBLICATION DATE: 02/08/2018 Name: PLUM ISLAND PLUM GUT HARBOR NY NOAA Chart: 13209 Latitude: 41° 10.3' N ( 41.17170) USGS Quad: PLUM ISLAND Longitude: 72° 12.3' W ( -72.20500) T I D A L B E N C H M A R K S BENCH MARK STAMPING: NO 9 1964 DESIGNATION: 851 1236 TIDAL 9 MONUMENTATION: Bench Mark disk VM#: 2282 AGENCY: National Geodetic Survey (NGS) IDB PID#: SETTING CLASSIFICATION: Concrete base OPUS PID: LATITUDE: 41° 10.4' N ( 41.17306) LONGITUDE: 72° 12.3' W ( -72.20472) The bench mark is a disk set in the NE corner of a concrete base for a steel mooring post at the main wharf of the harbor, 47.00 (154.2 ft) south of a flag pole, 46.94 m (154.0 ft) SE of a fuel pump riser pipe, 2.80 m (9.2 ft) NW of the bulkhead, 0.37 m (1.2 ft) north of a steel mooring post, and 0.15 m (0.5 ft) below the ground surface. BENCH MARK STAMPING: 1236 A 1989 DESIGNATION: 851 1236 A 1989 MONUMENTATION: Bench Mark disk VM#: 2283 AGENCY: National Geodetic Survey (NGS) IDB PID#: SETTING CLASSIFICATION: Stainless steel rod OPUS PID: LATITUDE: 41° 10.4' N ( 41.17306) LONGITUDE: 72° 12.3' W ( -72.20472) The bench mark is a disk crimped to a stainless steel rod, located on the NW side of the harbor, near the dock warehouse, 72.45 m (237.7 ft) north of the sea wall at the center line of the loading ramp for Plum Island, 53.64 m (176.0 ft) west of a pipeline at the point where it passes through the fence, 11.06 m (36.3 ft) east of the center line of the steps to the warehouse loading dock, 0.94 m (3.1 ft) south of the SE corner and in line with the east face of the warehouse building. The bench mark is 0.03 m (0.1 ft) below the ground surface, crimped to a stainless steel rod driven 17 m (56 ft) to refusal, and encased in a 5-inch PVC pipe.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 5 of 6 Station ID: 8511236 PUBLICATION DATE: 02/08/2018 Name: PLUM ISLAND PLUM GUT HARBOR NY NOAA Chart: 13209 Latitude: 41° 10.3' N ( 41.17170) USGS Quad: PLUM ISLAND Longitude: 72° 12.3' W ( -72.20500) T I D A L D A T U M S Tidal datums at PLUM ISLAND PLUM GUT HARBOR based on: LENGTH OF SERIES: 6 MONTHS TIME PERIOD: May 1989 - October 1989 TIDAL EPOCH: 1983-2001 CONTROL TIDE STATION: 8461490 NEW LONDON, THAMES RIVER Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in METERS: MEAN HIGHER HIGH WATER MHHW = 0.942 MEAN HIGH WATER MHW = 0.852 North American Vertical Datum NAVD88 = 0.591 MEAN SEA LEVEL MSL = 0.464 MEAN TIDE LEVEL MTL = 0.456 MEAN LOW WATER MLW = 0.060 MEAN LOWER LOW WATER MLLW = 0.000 North American Vertical Datum (NAVD88) Bench Mark Elevation Information In METERS above: Stamping or Designation MLLW MHW TIDAL 4 STA II 24 2.086 1.234 NO 7 1957 2.525 1.673 NO 8 1961 2.703 1.851 NO 9 1964 1.973 1.121 1236 A 1989 3.555 2.703
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 6 of 6 Station ID: 8511236 PUBLICATION DATE: 02/08/2018 Name: PLUM ISLAND PLUM GUT HARBOR NY NOAA Chart: 13209 Latitude: 41° 10.3' N ( 41.17170) USGS Quad: PLUM ISLAND Longitude: 72° 12.3' W ( -72.20500) 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.