U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Datums Page Page 1 of 6
Station ID: 9751749 PUBLICATION DATE: 07/26/2021
Name: CROWN BAY
VI
NOAA Chart: 25649 Latitude: 18° 20.0' N ( 18.33289)
USGS Quad: CHARLOTTE AMALIE Longitude: 64° 57.1' W ( -64.95169)
To reach from the U.S. Coast Guard Station on Veterans Drive in Charlotte
Amalie, proceed west on Veterans Drive for 2.2 km (1.4 mi) to a "Y" intersection
with Subbase Road, turn left onto Subbase Road and continue SW for 0.6 km (0.4
mi) to an unnamed road on the left that leads into Crown Bay Marina, turn left
onto this unnamed road and proceed SE for 70 m (234 ft) to a manned gate at the
entrance to the pier, proceed through the gate and head east for 0.2 km (0.1 mi)
to the end of the pier. The bench marks are in the vicinity of the eastern end
of the pier and along Hardwood Highway. The sensor was located at the eastern
end of the pier adjacent to a USGS water level sensor.
T I D A L B E N C H M A R K S
PRIMARY BENCH MARK STAMPING: 1749 A 2020
DESIGNATION: 975 1749 A
MONUMENTATION: Tidal Station disk VM#: 23564
AGENCY: National Ocean Service (NOS) IDB PID:
SETTING CLASSIFICATION: Concrete Pier OPUS PID#: BBHB71
LATITUDE: 18° 20.0' N ( 18.33286) LONGITUDE: 64° 57.1' W ( -64.95181)
The primary bench mark is a disk set in concrete near the centerline of the
pier, 85.63 m (280.9 ft) SSE of bench mark CORI, 20.13 m (66.0 ft) east of of a
light pole and 10 m (32.8 ft) west of the eastern end of the pier.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 2 of 6
Station ID: 9751749 PUBLICATION DATE: 07/26/2021
Name: CROWN BAY
VI
NOAA Chart: 25649 Latitude: 18° 20.0' N ( 18.33289)
USGS Quad: CHARLOTTE AMALIE Longitude: 64° 57.1' W ( -64.95169)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: CORI 2007
DESIGNATION: CORI
MONUMENTATION: Vertical Control disk VM#: 23565
AGENCY: National Geodetic Survey (NGS) IDB PID#: DL3915
SETTING CLASSIFICATION: Seawall OPUS PID#: DL3915
LATITUDE: 18° 20.0' N ( 18.33317) LONGITUDE: 64° 57.2' W ( -64.95255)
The bench mark is a brass disk set in a concrete seawall along the SW side of
the pier in the Crown Bay Marina, 30.4 m (99.7 ft) NW of the NW corner of a
transformer, 12.3 m (40.4 ft) SE of the SE corner of a transformer, 1.2 m (3.9
ft) NW of a ballard and 0.4 m (1.3 ft) SW of the bulkhead.
BENCH MARK STAMPING: 1749 B 2020
DESIGNATION: 975 1749 B
MONUMENTATION: Tidal Station disk VM#: 23566
AGENCY: National Ocean Service (NOS) IDB PID:
SETTING CLASSIFICATION: Concrete Sidewalk OPUS PID:
LATITUDE: 18° 20.0' N ( 18.33352) LONGITUDE: 64° 57.2' W ( -64.95388)
The bench mark is a disk set on the NE side of a 1.5 m (4.9 ft) wide concrete
sidewalk, 38.10 m (125.0 ft) SW of a light pole on the SE side of subbase road,
26.58 m (87.2 ft) east of a flagpole on the NE side of the parking lot for Crown
Bay Center, 7.16 m (23.5 ft) WNW of the SW corner of a chain link fence
surrounding a utility vault and 6.71 m (22.0 ft) south of a fire hydrant.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 3 of 6
Station ID: 9751749 PUBLICATION DATE: 07/26/2021
Name: CROWN BAY
VI
NOAA Chart: 25649 Latitude: 18° 20.0' N ( 18.33289)
USGS Quad: CHARLOTTE AMALIE Longitude: 64° 57.1' W ( -64.95169)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: SUB 1985
DESIGNATION: SUB
MONUMENTATION: Tidal Station disk VM#: 23567
AGENCY: National Ocean Service (NOS) IDB PID#: TV1547
SETTING CLASSIFICATION: Concrete Pier OPUS PID:
LATITUDE: 18° 19.9' N ( 18.33122) LONGITUDE: 64° 57.2' W ( -64.95252)
The bench mark is a disk set in concrete within a drillhole in the pier surface,
95.10 m (312.0 ft) WSW of a 3.5 m (11.5 ft) diameter concrete dolphin, 78.67 m
(258.1 ft) SE of a flagpole and 0.41 m (1.3 ft) NW of the southeastern corner of
the pier.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 4 of 6
Station ID: 9751749 PUBLICATION DATE: 07/26/2021
Name: CROWN BAY
VI
NOAA Chart: 25649 Latitude: 18° 20.0' N ( 18.33289)
USGS Quad: CHARLOTTE AMALIE Longitude: 64° 57.1' W ( -64.95169)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: A 1000 2007
DESIGNATION: A 1000
MONUMENTATION: Vertical Control disk VM#: 23568
AGENCY: National Geodetic Survey (NGS) IDB PID#: DL3914
SETTING CLASSIFICATION: OPUS PID:
LATITUDE: 18° 20.3' N ( 18.33853) LONGITUDE: 64° 56.7' W ( -64.94553)
The bench mark is a brass disk set in a 0.6 m (2.0 ft) x 0.6 m (2.0 ft) x 0.3 m
(1.0 ft) rock outcrop at the base of a hill, 18.9 m (62.0 ft) east of the SE
corner of a retaining wall, 15 m (49.2 ft) south of the centerline of a
driveway, 11.6 m (38.1 ft) north of the centerline of Highway 308 (Hardwood
Highway), 10.3 m (33.8 ft) SE of a utility pole, 3.9 m (12.8 ft) north of the
northern edge of a sidewalk, 3.9 m (12.8 ft) north of the northern edge of a
sidewalk and 0.4 m (1.3 ft) above the centerline of the highway.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 5 of 6
Station ID: 9751749 PUBLICATION DATE: 07/26/2021
Name: CROWN BAY
VI
NOAA Chart: 25649 Latitude: 18° 20.0' N ( 18.33289)
USGS Quad: CHARLOTTE AMALIE Longitude: 64° 57.1' W ( -64.95169)
T I D A L D A T U M S
Tidal datums at CROWN BAY based on:
LENGTH OF SERIES: 3 MONTHS
TIME PERIOD: December 2020 - February 2021
TIDAL EPOCH: 1983-2001
CONTROL TIDE STATION: 9751364 CHRISTIANSTED, ST. CROIX ISLAND
Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in METERS:
MEAN HIGHER HIGH WATER MHHW = 0.238
MEAN HIGH WATER MHW = 0.232
Virgin Islands Vertical Datum of 2009 VIVD09 = 0.123
MEAN TIDE LEVEL MTL = 0.122
MEAN SEA LEVEL MSL = 0.116
MEAN LOW WATER MLW = 0.011
MEAN LOWER LOW WATER MLLW = 0.000
Bench Mark Elevation Information In METERS above:
Stamping or Designation MLLW MHW
1749 A 2020 1.888 1.656
CORI 2007 1.297 1.065
1749 B 2020 3.143 2.911
SUB 1985 1.958 1.726
A 1000 2007 4.795 4.563
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 6 of 6
Station ID: 9751749 PUBLICATION DATE: 07/26/2021
Name: CROWN BAY
VI
NOAA Chart: 25649 Latitude: 18° 20.0' N ( 18.33289)
USGS Quad: CHARLOTTE AMALIE Longitude: 64° 57.1' W ( -64.95169)
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.