U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Datums Page Page 1 of 5 Station ID: 9751540 PUBLICATION DATE: 05/23/2003 Name: REDHOOK BAY, ST THOMAS, USVI VI NOAA Chart: 25647 Latitude: 18° 19.6' N ( 18.32670) USGS Quad: EASTERN ST THOMAS Longitude: 64° 51.1' W ( -64.85170) To reach the tidal bench marks from the intersection of Mafolic Road and Sugar Estate Road (Route 38) in downtown Charlotte Amalie, proceed east on Route 38 (turns into Weymouth Reymer Highway) for 5 km (3 mi) to Turpentine Run Road (Route 32), then SE on Route 32 for 2 km (1 mi) to Redhook Road (Route 32), then east on Redhook Road for 2.4 km (1.5 mi) to the entrance to National Park Service (NPS) Redhook Bay Park, continue into the park for 0.8 km (0.5 mi) to NPS Redhook Bay Visitors Station. The bench marks are near the visitors station. The tide gage and staff were located on the NPS pier. T I D A L B E N C H M A R K S PRIMARY BENCH MARK STAMPING: NO 1 1973 DESIGNATION: 975 1540 TIDAL 1 MONUMENTATION: Tidal Station disk VM#: 7933 AGENCY: US Coast and Geodetic Survey (USC&GS) IDB PID#: SETTING CLASSIFICATION: Concrete foundation OPUS PID: LATITUDE: 18° 19.5' N ( 18.32500) LONGITUDE: 64° 51.0' W ( -64.85000) The primary bench mark is a disk set flush in the center of the concrete foundation of the NPS antenna tower, and 6.61 m (21.7 ft) west of the SW corner of the NPS Visitors Station building.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 2 of 5 Station ID: 9751540 PUBLICATION DATE: 05/23/2003 Name: REDHOOK BAY, ST THOMAS, USVI VI NOAA Chart: 25647 Latitude: 18° 19.6' N ( 18.32670) USGS Quad: EASTERN ST THOMAS Longitude: 64° 51.1' W ( -64.85170) T I D A L B E N C H M A R K S BENCH MARK STAMPING: NO 2 1973 DESIGNATION: 975 1540 TIDAL 2 MONUMENTATION: Tidal Station disk VM#: 7934 AGENCY: US Coast and Geodetic Survey (USC&GS) IDB PID#: SETTING CLASSIFICATION: Concrete foundation OPUS PID: LATITUDE: 18° 19.5' N ( 18.32500) LONGITUDE: 64° 51.0' W ( -64.85000) The bench mark is a disk set flush in the concrete foundation on the south side of the NPS Visitors Station building, and 11 m (37 ft) east of the south entrance to the building. BENCH MARK STAMPING: NO 3 1973 DESIGNATION: 975 1540 TIDAL 3 MONUMENTATION: Tidal Station disk VM#: 7935 AGENCY: US Coast and Geodetic Survey (USC&GS) IDB PID#: SETTING CLASSIFICATION: Concrete footing OPUS PID: LATITUDE: 18° 19.5' N ( 18.32500) LONGITUDE: 64° 51.0' W ( -64.85000) The bench mark is a disk set flush in the concrete footing on the NW corner of the NPS headquarters office building, and 10 m (34 ft) from the entrance to the building.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 3 of 5 Station ID: 9751540 PUBLICATION DATE: 05/23/2003 Name: REDHOOK BAY, ST THOMAS, USVI VI NOAA Chart: 25647 Latitude: 18° 19.6' N ( 18.32670) USGS Quad: EASTERN ST THOMAS Longitude: 64° 51.1' W ( -64.85170) T I D A L B E N C H M A R K S BENCH MARK STAMPING: USDI 1 ELEV 2.82 NPS DESIGNATION: 975 1540 USDI 1 ELEV 2.82 MONUMENTATION: Survey disk VM#: 7936 AGENCY: National Park Service (NPS) IDB PID#: SETTING CLASSIFICATION: Concrete bulkhead foundation OPUS PID: LATITUDE: 18° 19.5' N ( 18.32500) LONGITUDE: 64° 51.0' W ( -64.85000) The bench mark is a disk set flush in the NE corner of the concrete bulkhead foundation, 12 m (39 ft) NE of the NE corner of the NPS Visitors Station building, and 0.3 m (1 ft) SW of the NE corner. BENCH MARK STAMPING: USDI 2 ELEV 2.85 NPS DESIGNATION: 975 1540 USDI 2 ELEV 2.85 MONUMENTATION: Survey disk VM#: 7937 AGENCY: National Park Service (NPS) IDB PID#: SETTING CLASSIFICATION: Concrete bulkhead foundation OPUS PID: LATITUDE: 18° 19.5' N ( 18.32500) LONGITUDE: 64° 51.0' W ( -64.85000) The bench mark is a disk set flush in the concrete bulkhead foundation, 10.82 m (35.5 ft) NE of the NW bulkhead corner, and 1 m (4 ft) SW of the foot of the pier.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 4 of 5 Station ID: 9751540 PUBLICATION DATE: 05/23/2003 Name: REDHOOK BAY, ST THOMAS, USVI VI NOAA Chart: 25647 Latitude: 18° 19.6' N ( 18.32670) USGS Quad: EASTERN ST THOMAS Longitude: 64° 51.1' W ( -64.85170) T I D A L D A T U M S Tidal datums at REDHOOK BAY, ST THOMAS, USVI based on: LENGTH OF SERIES: 2 MONTHS TIME PERIOD: February 1975 - March 1975 TIDAL EPOCH: 1983-2001 CONTROL TIDE STATION: 9751639 CHARLOTTE AMALIE, ST. THOMAS Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in METERS: MEAN HIGHER HIGH WATER MHHW = 0.332 MEAN HIGH WATER MHW = 0.288 MEAN TIDE LEVEL MTL = 0.164 MEAN SEA LEVEL MSL = 0.158 MEAN LOW WATER MLW = 0.039 MEAN LOWER LOW WATER MLLW = 0.000 Bench Mark Elevation Information In METERS above: Stamping or Designation MLLW MHW NO 1 1973 1.050 0.762 NO 2 1973 0.991 0.703 NO 3 1973 2.295 2.007 USDI 1 ELEV 2.82 NPS 0.905 0.617 USDI 2 ELEV 2.85 NPS 0.913 0.625
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 5 of 5 Station ID: 9751540 PUBLICATION DATE: 05/23/2003 Name: REDHOOK BAY, ST THOMAS, USVI VI NOAA Chart: 25647 Latitude: 18° 19.6' N ( 18.32670) USGS Quad: EASTERN ST THOMAS Longitude: 64° 51.1' W ( -64.85170) 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 any other fixed island datum. This tide station location has a defined island datum (VIVD09). Island datums are specific fixed geodetic datums whose elevation relationship to local MSL and other tidal datums may not be consistent from one location to another. Virgin Islands Vertical Datum of 2009 (VIVD09) is a fixed datum derived from a simultaneous, least squares, minimum constraint adjustment of leveling observations. Local mean sea level relative to the 1983-2001 National Tidal Datum Epoch observed at tide stations 9751401 located at Lime Tree Bay, St. Croix, 9751381 located at Lameshur Bay, St. John, and 9751639 located at Charlotte Amalie, St Thomas was held fixed as the single initial constraint. VIVD09 replaces all previous height system as the national standard geodetic reference for heights in the Virgin Islands. Bench mark elevations relative to VIVD09 are available from NGS through the World Wide Web at National Geodetic Survey. 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 VIVD09 elevation is shown on the Elevations of Tidal Datums Table Referred to MLLW only when two or more of the bench marks listed have VIVD09 elevations. The VIVD09 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, VIVD09 bench mark elevations computed indirectly from the tidal datums elevation table may differ slightly from VIVD09 elevations listed for each bench mark in the NGS database.