U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Datums Page Page 1 of 5
Station ID: 9751309 PUBLICATION DATE: 11/18/2011
Name: LEINSTER POINT, LEINSTER BAY, ST. JOHN'S
VI
NOAA Chart: 25641 Latitude: 18° 22.1' N ( 18.36761)
USGS Quad: WESTERN ST JOHN Longitude: 64° 43.2' W ( -64.72072)
To reach the tidal bench marks from the National Park Service Visitor Center at
St John, Cruz Bay, travel east from the Visitor Center for 200 m (0.1 mi) to
North Shore Road Route 20 and turn left, then take another immediate left to
stay on Route 20 at the NPS Maintenance Area signs, and continue on Route 20 as
it winds eastward for 9.0 km (5.6 mi) towards Annaberg to a fork in the road
where the east bound and west bound lanes split, continue east on Route 20 for
another 1.1 km (0.7 mi) to a stop sign, turn right towards Annaberg and travel
east 400 m (0.2 mi) to the Annaberg Plantation parking lot, continue east on
foot along the trail that starts on the beach just east of the parking lot for
1.24 km (0.77 mi) as it follows the shoreline around Leinster Bay and Watermelon
Bay to a tidal stream at the SE end of the sandy beach on Watermelon Bay, cross
the stream and continue NE on the trail in the woods along the beach for 0.13 km
(0.1 mi) to a fork in the trail, take the less traveled trail to the left
continuing along the shoreline to the NW for 0.31 km (0.2 mi) to where the trail
dead ends into the beach, follow the shoreline north for 0.22 km (0.13 mi) to
the end of Leinster Point. The bench marks are in the bedrock on either side of
the point.
T I D A L B E N C H M A R K S
PRIMARY BENCH MARK STAMPING: 1309 A 2010
DESIGNATION: 975 1309 A
MONUMENTATION: Tidal Station disk VM#: 19777
AGENCY: National Ocean Service (NOS) IDB PID#:
SETTING CLASSIFICATION: Bedrock outcrop. OPUS PID#: BBCH99
LATITUDE: 18° 22.1' N ( 18.36764) LONGITUDE: 64° 43.2' W ( -64.72033)
The primary bench mark is set flush in bedrock on the east side of Leinster
Point near the north end of a sand and gravel beach, 19.05 m (62.5 ft) south of
bench mark 975 1309 B, 7.45 m (24.4 ft) north of the north end of the beach,
4.54 m (14.9 ft) east of a prominent triangular shattered bedrock cliff face
extending out of the grass and trees above the north end of the beach, and 0.99
m (3.25 ft) SE of vegetation line.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 2 of 5
Station ID: 9751309 PUBLICATION DATE: 11/18/2011
Name: LEINSTER POINT, LEINSTER BAY, ST. JOHN'S
VI
NOAA Chart: 25641 Latitude: 18° 22.1' N ( 18.36761)
USGS Quad: WESTERN ST JOHN Longitude: 64° 43.2' W ( -64.72072)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 1309 B 2010
DESIGNATION: 975 1309 B
MONUMENTATION: Tidal Station disk VM#: 19778
AGENCY: National Ocean Service (NOS) IDB PID#:
SETTING CLASSIFICATION: Bedrock outcrop. OPUS PID:
LATITUDE: 18° 22.1' N ( 18.36781) LONGITUDE: 64° 43.2' W ( -64.72028)
The bench mark is set flush in an elevated section of bedrock extending to the
NE on the east side of the end of Leinster Point, 60.21 m (197.5 ft) NE of bench
mark 975 1309 C measured around the end of the point, 25.61 m (84.0 ft) north of
the north end of the beach on the east side of Leinster Point, 4.35 m (14.25 ft)
NE of a 6 m (20 ft) tall cliff face on the east side of Leinster Point, and 1.59
m (5.2 ft) above the surrounding bedrock and gravel beach.
BENCH MARK STAMPING: 1309 C 2010
DESIGNATION: 975 1309 C
MONUMENTATION: Tidal Station disk VM#: 19779
AGENCY: National Ocean Service (NOS) IDB PID#:
SETTING CLASSIFICATION: Bedrock outcrop. OPUS PID:
LATITUDE: 18° 22.1' N ( 18.36758) LONGITUDE: 64° 43.2' W ( -64.72072)
The bench mark is set flush in an outcropping of striped bedrock on the west
side of the end of Leinster Point, 60.21 m (197.5 ft) SW of bench mark 975 1309
B measured around the end of the point, 16.95 m (55.6 ft) NE of bench mark 975
1309 D measured on a curve along the shore, 8.33 m (27.3 ft) south of a large
1.0 m x 2.6 m x 1.4 m (3.2 ft x 8.5 ft x 4.6 ft) angular boulder offshore of the
point, 0.84 m (2.75 ft) NW of a cliff face of the NW side of the end of the
point, and 0.91 m (2.9 ft) above the surrounding stone beach.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 3 of 5
Station ID: 9751309 PUBLICATION DATE: 11/18/2011
Name: LEINSTER POINT, LEINSTER BAY, ST. JOHN'S
VI
NOAA Chart: 25641 Latitude: 18° 22.1' N ( 18.36761)
USGS Quad: WESTERN ST JOHN Longitude: 64° 43.2' W ( -64.72072)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 1309 D 2010
DESIGNATION: 975 1309 D
MONUMENTATION: Tidal Station disk VM#: 19780
AGENCY: National Ocean Service (NOS) IDB PID#:
SETTING CLASSIFICATION: Bedrock outcrop. OPUS PID:
LATITUDE: 18° 22.0' N ( 18.36747) LONGITUDE: 64° 43.2' W ( -64.72075)
The bench mark is set flush in small ledge in a bedrock wall on the west side of
Leinster Point, 92.32 m (302.8 ft) north of bench mark 975 1309 E, 16.95 m (55.6
ft) SW of bench mark 975 1309 C measured on a curve along the shore, 11.57 m
(37.9 ft) north of the north end of the gravel beach that runs along the west
side of the point, 2.91 m (9.5 ft) north of the most western point of the dark
bedrock outcrop, and 1.22 m (4.0 ft) above the level of the surrounding stone
beach.
BENCH MARK STAMPING: 1309 E 2010
DESIGNATION: 975 1309 E
MONUMENTATION: Tidal Station disk VM#: 19781
AGENCY: National Ocean Service (NOS) IDB PID#:
SETTING CLASSIFICATION: Bedrock outcrop. OPUS PID:
LATITUDE: 18° 23.0' N ( 18.38331) LONGITUDE: 64° 43.2' W ( -64.72064)
The bench mark is set flush in a low bedrock outcrop at the south end of the
gravel beach on the west side of Leinster Point, 92.32 m (302.8 ft) south of
bench mark 975 1309 D, 22.86 m (74.9 ft) south of the only other bedrock outcrop
visible along this beach before nearing the end of the point, 1.67 m (5.4 ft)
south of the south end of the beach. 1.26 m (4.1 ft) west of the tree line, and
0.46 m (1.5 ft) above the level of the beach.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 4 of 5
Station ID: 9751309 PUBLICATION DATE: 11/18/2011
Name: LEINSTER POINT, LEINSTER BAY, ST. JOHN'S
VI
NOAA Chart: 25641 Latitude: 18° 22.1' N ( 18.36761)
USGS Quad: WESTERN ST JOHN Longitude: 64° 43.2' W ( -64.72072)
T I D A L D A T U M S
Tidal datums at LEINSTER POINT, LEINSTER BAY, ST. JOHN'S based on:
LENGTH OF SERIES: 4 MONTHS
TIME PERIOD: December 2010 - March 2011
TIDAL EPOCH: 1983-2001
CONTROL TIDE STATION: 9755371 SAN JUAN, LA PUNTILLA, SAN JUAN BAY
Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in METERS:
MEAN HIGHER HIGH WATER MHHW = 0.342
MEAN HIGH WATER MHW = 0.274
MEAN SEA LEVEL MSL = 0.159
MEAN TIDE LEVEL MTL = 0.156
MEAN LOW WATER MLW = 0.037
MEAN LOWER LOW WATER MLLW = 0.000
Bench Mark Elevation Information In METERS above:
Stamping or Designation MLLW MHW
1309 A 2010 1.428 1.154
1309 B 2010 1.618 1.344
1309 C 2010 1.442 1.168
1309 D 2010 1.822 1.548
1309 E 2010 1.273 0.999
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 5 of 5
Station ID: 9751309 PUBLICATION DATE: 11/18/2011
Name: LEINSTER POINT, LEINSTER BAY, ST. JOHN'S
VI
NOAA Chart: 25641 Latitude: 18° 22.1' N ( 18.36761)
USGS Quad: WESTERN ST JOHN Longitude: 64° 43.2' W ( -64.72072)
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.