U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Datums Page Page 1 of 8
Station ID: 9751639 PUBLICATION DATE: 09/27/2017
Name: CHARLOTTE AMALIE, ST. THOMAS
VI
NOAA Chart: 25649 Latitude: 18° 20.1' N ( 18.33583)
USGS Quad: CENTRAL ST THOMAS Longitude: 64° 55.2' W ( -64.92000)
To reach the tidal bench marks from the Harry S. Truman Airport on St. Thomas,
take Airport Road to Highway 30, proceed on Highway 30 east to Charlotte Amalie,
then continue on Highway 30 past the U.S. Coast Guard Dock at Kings Wharf to
the Havensight Mall and West Indian Cruise Ship Dock about 5.6 km (3.5 mi) from
Airport Road). The bench marks are on the West Indian Dock compound, along
Highway 30, and on the U.S. Coast Guard compound. The tide station is at the NE
end of the West Indian Dock compound at the base of a small wooden pier.
T I D A L B E N C H M A R K S
PRIMARY BENCH MARK STAMPING: 1639 F 1983
DESIGNATION: 975 1639 F
MONUMENTATION: Tidal Station disk VM#: 1372
AGENCY: National Ocean Survey (NOS) IDB PID#: DL3908
SETTING CLASSIFICATION: Concrete mooring base OPUS PID#: DL3908
LATITUDE: 18° 20.1' N ( 18.33503) LONGITUDE: 64° 55.2' W ( -64.91958)
The primary bench mark is a disk set flush in the east corner of a 1.83 m x 2.44
m (6.0 ft x 8.01 ft) concrete mooring bit base in the West Indian Dock compound
(bollard no longer exists), 25.05 m (82.18 ft) west of the concrete block wall
of the Yacht Haven parking lot, 11.70 m (38.39 ft) north of the north face of a
cargo loading ramp, 5.18 m (16.99 ft) ENE of the west face of the bulkhead, and
0.61 m (2.0 ft) above the pier deck.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 2 of 8
Station ID: 9751639 PUBLICATION DATE: 09/27/2017
Name: CHARLOTTE AMALIE, ST. THOMAS
VI
NOAA Chart: 25649 Latitude: 18° 20.1' N ( 18.33583)
USGS Quad: CENTRAL ST THOMAS Longitude: 64° 55.2' W ( -64.92000)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: NO 3 1975
DESIGNATION: 975 1639 TIDAL 3
MONUMENTATION: Tidal Station disk VM#: 1375
AGENCY: National Ocean Survey (NOS) IDB PID#: DL3911
SETTING CLASSIFICATION: Concrete pad OPUS PID:
LATITUDE: 18° 20.4' N ( 18.33983) LONGITUDE: 64° 55.8' W ( -64.93000)
The bench mark is a disk set flush in a concrete pad at the U.S. Coast Guard
Station on the south side of the base near the water, 12.47 m (40.9 ft) west of
the most westerly of two black cannons, 10.03 m (32.9 ft) north of the concrete
at the water's edge, 6.89 m (22.6 ft) south of the SW corner of a garage, and
flush with the concrete.
BENCH MARK STAMPING: NO 5 1975
DESIGNATION: 975 1639 TIDAL 5
MONUMENTATION: Tidal Station disk VM#: 1377
AGENCY: National Ocean Survey (NOS) IDB PID#: DL3910
SETTING CLASSIFICATION: Concrete step OPUS PID:
LATITUDE: 18° 20.4' N ( 18.34014) LONGITUDE: 64° 55.8' W ( -64.92972)
The bench mark is a disk set flush on the west side of the entrance to the main
Administration Building at the U.S. Coast Guard Station, 8.32 m (27.3 ft) east
of the east curb of the road leading to the station, 1.98 m (6.5 ft) SW of the
NW side of the concrete landing, 1.07 m (3.5 ft) west of the foundation of the
building, and flush with the ground.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 3 of 8
Station ID: 9751639 PUBLICATION DATE: 09/27/2017
Name: CHARLOTTE AMALIE, ST. THOMAS
VI
NOAA Chart: 25649 Latitude: 18° 20.1' N ( 18.33583)
USGS Quad: CENTRAL ST THOMAS Longitude: 64° 55.2' W ( -64.92000)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 1639 L 1986
DESIGNATION: 975 1639 L
MONUMENTATION: Tidal Station disk VM#: 1385
AGENCY: National Ocean Survey (NOS) IDB PID#: DL3909
SETTING CLASSIFICATION: Concrete retaining wall OPUS PID:
LATITUDE: 18° 20.3' N ( 18.33817) LONGITUDE: 64° 55.5' W ( -64.92561)
The bench mark is a disk set flush in the top of a 0.3 m (1 ft) wide concrete
retaining wall extending from the south face of the salt water pumping station
on the south side of Highway 30, 11.34 m (37.2 ft) south of the NE corner of the
Pumping Station Building, 2.53 m (8.3 ft) west of the west curb of the highway,
1.13 m (3.7 ft) east of the SE corner of the building, and 0.70 m (2.3 ft) above
the sidewalk.
BENCH MARK STAMPING: 1639 N 1991
DESIGNATION: 975 1639 N
MONUMENTATION: Tidal Station disk VM#: 4614
AGENCY: National Ocean Service (NOS) IDB PID#:
SETTING CLASSIFICATION: Concrete pier deck OPUS PID:
LATITUDE: 18° 19.9' N ( 18.33122) LONGITUDE: 64° 55.5' W ( -64.92483)
The benchmark is a disk set flush on the new concrete pier deck extension of the
West Indies Dock compund on the west side of the dock, 11.98 m (39.3 ft) NE of
the second light pole, 8.53 m (27.99 ft) SE of the NW face of the dock, 1.22 m
(4.0 ft) SW of the first light pole, and 0.61 m (2.0 ft) NW of the southern
water's edge.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 4 of 8
Station ID: 9751639 PUBLICATION DATE: 09/27/2017
Name: CHARLOTTE AMALIE, ST. THOMAS
VI
NOAA Chart: 25649 Latitude: 18° 20.1' N ( 18.33583)
USGS Quad: CENTRAL ST THOMAS Longitude: 64° 55.2' W ( -64.92000)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 1639 P 2001
DESIGNATION: 975 1639 P
MONUMENTATION: Tidal Station disk VM#: 16777
AGENCY: National Ocean Service (NOS) IDB PID#:
SETTING CLASSIFICATION: Concrete pier OPUS PID:
LATITUDE: 18° 19.9' N ( 18.33167) LONGITUDE: 64° 55.4' W ( -64.92417)
The bench mark is a disk set flush near the western end of the concrete pier on
the West Indies dock compound, 30.2 m (99.1 ft) west of the 4th bollard counting
from the western end, 17.8 m (58.4 ft) east of the 2nd bollard counting from the
western end of the pier, 15.2 m (49.9 ft) north of the centerline of a paved
road only for taxis which runs easterly and parallel to the cruise ships, 2.85 m
(9.35 ft) north of the 3rd bollard counting from the western end of the docks,
and 0.5 m (1.6 ft) south of the waters edge at the pier face. Note: A spaced row
of bollards on the original docks runs east and west, these are large and 0.6 m
(2 ft) tall and not to be mixed up with the pairs of small bitts also running
east and west.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 5 of 8
Station ID: 9751639 PUBLICATION DATE: 09/27/2017
Name: CHARLOTTE AMALIE, ST. THOMAS
VI
NOAA Chart: 25649 Latitude: 18° 20.1' N ( 18.33583)
USGS Quad: CENTRAL ST THOMAS Longitude: 64° 55.2' W ( -64.92000)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 1639 R 2007
DESIGNATION: 975 1639 R
MONUMENTATION: Tidal Station disk VM#: 18310
AGENCY: National Ocean Service (NOS) IDB PID#:
SETTING CLASSIFICATION: Concrete walkway OPUS PID:
LATITUDE: 18° 19.9' N ( 18.33250) LONGITUDE: 64° 55.3' W ( -64.92114)
The BM is a desk set flush in a concrete drain located near the main pass office
for homeland security and the west indies dock, 13.74 m (45.08 ft) SE of the
corner of the calabash gift shop, 7.81 m (25.62 ft) ENE of the NE corner of the
pass office, and 5.51 m (18.08 ft) SSE of the centerline of the main road
running parrallel to the docks, set flush in a 1.25 m (4.10 ft) X 1.40 m (4.59
ft) concrete drain.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 6 of 8
Station ID: 9751639 PUBLICATION DATE: 09/27/2017
Name: CHARLOTTE AMALIE, ST. THOMAS
VI
NOAA Chart: 25649 Latitude: 18° 20.1' N ( 18.33583)
USGS Quad: CENTRAL ST THOMAS Longitude: 64° 55.2' W ( -64.92000)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: BETSY 1993
DESIGNATION: BETSY
MONUMENTATION: Bench Mark disk VM#: 18647
AGENCY: National Ocean Survey/Service (NOS) IDB PID#:
SETTING CLASSIFICATION: Concrete pier OPUS PID:
LATITUDE: 18° 19.8' N ( 18.33044) LONGITUDE: 64° 55.6' W ( -64.92625)
The BM is a disk set flush in the concrete near the west end of the cruise ship
pier, 95.5m (313.3 ft) East of the watern most end of pier, 7.7m (25.3 ft) North
of the first cut in on the south side of the pier and 1.45m (4.8 ft) south of
the north face of pier.
BENCH MARK STAMPING: 1639 S 2016
DESIGNATION: 975 1639 S
MONUMENTATION: Metal Rod VM#: 21916
AGENCY: National Ocean Service (NOS) IDB PID#:
SETTING CLASSIFICATION: Stainless Steel Rod OPUS PID:
LATITUDE: 18° 19.9' N ( 18.33197) LONGITUDE: 64° 55.3' W ( -64.92200)
The bench mark is a deep rod set in a flower bed just south of the main road
running east to west on the West Indies property, 27.7 m (90.9 ft) SW of the SW
corner of warehouse number 5, 7.9 m (25.9 ft) S of the centerline of main road
running east to west on West Indies property, 6.2 m (20.3 ft) E of the NW corner
of chain link fence surrounding West Indies generator building. The stainless
steel rod is encased in a 5 inch (13 cm) pvc pipe with logo cap and concrete
kick block approx. 3 inches (8 cm) above ground, driven 9.39m (30.8 ft) to
refusal.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 7 of 8
Station ID: 9751639 PUBLICATION DATE: 09/27/2017
Name: CHARLOTTE AMALIE, ST. THOMAS
VI
NOAA Chart: 25649 Latitude: 18° 20.1' N ( 18.33583)
USGS Quad: CENTRAL ST THOMAS Longitude: 64° 55.2' W ( -64.92000)
T I D A L D A T U M S
Tidal datums at CHARLOTTE AMALIE, ST. THOMAS based on:
LENGTH OF SERIES: 19 YEARS
TIME PERIOD: January 1983 - December 2001
TIDAL EPOCH: 1983-2001
CONTROL TIDE STATION:
Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in METERS:
HIGHEST OBSERVED WATER LEVEL (09/16/1995) = 1.133
MEAN HIGHER HIGH WATER MHHW = 0.240
MEAN HIGH WATER MHW = 0.227
MEAN TIDE LEVEL MTL = 0.121
MEAN SEA LEVEL MSL = 0.114
Virgin Islands Vertical Datum of 2009 VIVD09 = 0.114
MEAN LOW WATER MLW = 0.014
MEAN LOWER LOW WATER MLLW = 0.000
LOWEST OBSERVED WATER LEVEL (02/06/1985) = -0.449
Bench Mark Elevation Information In METERS above:
Stamping or Designation MLLW MHW
1639 F 1983 1.666 1.439
NO 3 1975 1.441 1.214
NO 5 1975 1.622 1.395
1639 L 1986 2.416 2.189
1639 N 1991 2.483 2.256
1639 P 2001 2.455 2.228
1639 R 2007 3.264 3.037
BETSY 1993 2.499 2.272
1639 S 2016 2.984 2.757
Foot Notes:
Bench mark 1639 S 2016 is based on one differential leveling connection and does
not meet the quality control standards of the NOS. Therefore, caution should be
used when deriving elevations for this mark.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 8 of 8
Station ID: 9751639 PUBLICATION DATE: 09/27/2017
Name: CHARLOTTE AMALIE, ST. THOMAS
VI
NOAA Chart: 25649 Latitude: 18° 20.1' N ( 18.33583)
USGS Quad: CENTRAL ST THOMAS Longitude: 64° 55.2' W ( -64.92000)
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.