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.