U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Datums Page Page 1 of 6
Station ID: 2431000 PUBLICATION DATE: 07/12/2016
Name: DIEGO GARCIA, INDIAN OCEAN.
NOAA Chart: Latitude: 7° 17.4' S ( -7.29000)
USGS Quad: Longitude: 72° 23.6' E ( 72.39330)
To reach the tidal bench marks from the MAC parking lot, turn left and head up
the small hill. At the stop sign, turn left; go 0.5 km (0.3 mi) until you come
to a blue sign on the left hand side of the road. The sign will say "Wharf A
Wharf B Small Boast Basin MSCU Bldg 469." Turn right, head down the road for
0.5 km (0.3 mi), turn left after you pass through the gate; go past the MSCU
building onto the dirt road. The tide station is inside a cinder block
buildings #460. NODC has the key.
T I D A L B E N C H M A R K S
PRIMARY BENCH MARK STAMPING: 1000 D 1990
DESIGNATION: 243 1000 D
MONUMENTATION: Survey disk VM#: 12396
AGENCY: National Ocean Service (NOS) IDB PID#:
SETTING CLASSIFICATION: Set in concrete OPUS PID:
LATITUDE: 7° 16.2' S ( -7.27000) LONGITUDE: 72° 23.8' E ( 72.39670)
The primary bench mark is a disk set in a concrete pad supporting ten electrical
switch panels, 79 m (260 ft) west of bench mark 1000 C 1990, 55 m (180 ft) SW of
wharf face, 1.83 m (6.0 ft) NE of northern-most switch box, and 0.15 m (0.5 ft)
south of the north corner.
BENCH MARK STAMPING: 1000 A 1990
DESIGNATION: 243 1000 A
MONUMENTATION: Survey disk VM#: 12393
AGENCY: National Ocean Service (NOS) IDB PID#:
SETTING CLASSIFICATION: Set in concrete OPUS PID:
LATITUDE: 7° 16.2' S ( -7.26917) LONGITUDE: 72° 23.8' E ( 72.39670)
The bench mark is a disk set in concrete near the NE face of the deep draft
wharf, 17 m (55 ft) NE of Building #460 and 0.40 m (1.30 ft) SW of the
northern-most bollard on wharf.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 2 of 6
Station ID: 2431000 PUBLICATION DATE: 07/12/2016
Name: DIEGO GARCIA, INDIAN OCEAN.
NOAA Chart: Latitude: 7° 17.4' S ( -7.29000)
USGS Quad: Longitude: 72° 23.6' E ( 72.39330)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 1000 B 1990
DESIGNATION: 243 1000 B
MONUMENTATION: Survey disk VM#: 12394
AGENCY: National Ocean Service (NOS) IDB PID#:
SETTING CLASSIFICATION: Set in concrete OPUS PID:
LATITUDE: 7° 16.2' S ( -7.27000) LONGITUDE: 72° 23.8' E ( 72.39670)
The bench mark is a disk set in concrete near the NE face of the deep draft
wharf, located near two bollards which are set between numbers 375 and 425 on
bullrail, 120 m (393 ft) SE of bench mark A and 0.46 m (1.5 ft) SW of bollards.
BENCH MARK STAMPING: 1000 C 1990
DESIGNATION: 243 1000 C
MONUMENTATION: Survey disk VM#: 12395
AGENCY: National Ocean Service (NOS) IDB PID#:
SETTING CLASSIFICATION: Set in concrete OPUS PID:
LATITUDE: 7° 16.2' S ( -7.27000) LONGITUDE: 72° 23.8' E ( 72.39670)
The bench mark is a disk set in concrete near the NE face of the deep draft
wharf, near to two bollards which are placed between numbers 725 and 800 on
bullrail, 119 m (390 ft) SE of bench mark B, and 0.46 m (1.5 ft) SW of bollards.
BENCH MARK STAMPING: 1000 E 1990
DESIGNATION: 243 1000 E
MONUMENTATION: Survey disk VM#: 12397
AGENCY: National Ocean Service (NOS) IDB PID#:
SETTING CLASSIFICATION: Set in concrete OPUS PID:
LATITUDE: 7° 16.2' S ( -7.27000) LONGITUDE: 72° 23.8' E ( 72.39670)
The bench mark is a disk set in concrete on the SE end of finger pier #4025 in
the small boat harbor, 1.68 m (5.50 ft) NW of SE end of pier, and 0.15 m (0.5
ft) NE of the SE edge of pier.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 3 of 6
Station ID: 2431000 PUBLICATION DATE: 07/12/2016
Name: DIEGO GARCIA, INDIAN OCEAN.
NOAA Chart: Latitude: 7° 17.4' S ( -7.29000)
USGS Quad: Longitude: 72° 23.6' E ( 72.39330)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 1000 F 1990
DESIGNATION: 243 1000 F
MONUMENTATION: Survey disk VM#: 12398
AGENCY: National Ocean Service (NOS) IDB PID#:
SETTING CLASSIFICATION: Set in concrete OPUS PID:
LATITUDE: 7° 16.2' S ( -7.27000) LONGITUDE: 72° 23.8' E ( 72.39670)
The bench mark is a disk set in the SE end of a concrete seawall at the SW end
of the small boat harbor, 12 m (39 ft) NW of the center of the NW entrance to
wharf, and 1.22 m (4.0 ft) NW of the SE end of seawall.
BENCH MARK STAMPING: 1000 G 1990
DESIGNATION: 243 1000 G
MONUMENTATION: Survey disk VM#: 12399
AGENCY: National Ocean Service (NOS) IDB PID#:
SETTING CLASSIFICATION: Set in concrete OPUS PID:
LATITUDE: 7° 16.2' S ( -7.27000) LONGITUDE: 72° 23.8' E ( 72.39670)
The bench mark is a disk set in a concrete sea wall at the SW end of small boat
harbor, located between numbers 325 and 350 on seawall, 195 ft north of north
end of Building #4005, and 110 m (360 ft) NW of bench mark 1000 F 1990.
BENCH MARK STAMPING: 1000 H 1991
DESIGNATION: 243 1000 H
MONUMENTATION: Survey disk VM#: 12400
AGENCY: National Ocean Service (NOS) IDB PID#:
SETTING CLASSIFICATION: Set in concrete OPUS PID:
LATITUDE: 7° 16.2' S ( -7.27000) LONGITUDE: 72° 23.8' E ( 72.39670)
The bench mark is a disk set in the SE end of Finger Pier #4027 in the small
boat harbor, 1.13 m (3.7 ft) NW of the SE end of the pier and 0.24 m (0.8 ft) NE
of the SW edge of the pier.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 4 of 6
Station ID: 2431000 PUBLICATION DATE: 07/12/2016
Name: DIEGO GARCIA, INDIAN OCEAN.
NOAA Chart: Latitude: 7° 17.4' S ( -7.29000)
USGS Quad: Longitude: 72° 23.6' E ( 72.39330)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 1000 J 1991
DESIGNATION: 243 1000 J
MONUMENTATION: Survey disk VM#: 12401
AGENCY: National Ocean Service (NOS) IDB PID#:
SETTING CLASSIFICATION: Set in concrete OPUS PID:
LATITUDE: 7° 16.2' S ( -7.27000) LONGITUDE: 72° 23.8' E ( 72.39670)
The bench mark is a disk set in the concrete entrance of the west roll up door
of the warehouse on the deep draft wharf, about 76 m (250 ft) SW of bench mark
1000 C 1990, 2.87 m (9.4 ft) NE of the door entering Building 461, 0.52 m (1.7
ft) east of a 1.22 m (4.0 ft) high black and yellow striped post, and 0.12 m
(0.4 ft) NE of the SW edge of a roll-up door.
BENCH MARK STAMPING: DDW1 EL 10
DESIGNATION: 243 1000 DDW1 EL 10
MONUMENTATION: Survey disk VM#: 12402
AGENCY: National Ocean Service (NOS) IDB PID#:
SETTING CLASSIFICATION: Set in concrete OPUS PID:
LATITUDE: 7° 16.2' S ( -7.27000) LONGITUDE: 72° 23.8' E ( 72.39670)
The bench mark is a disk set in concrete near the NE face of the deep draft
wharf, 14.54 m (47.7 ft) SW of the SW corner of Building #460, 8.20 m (26.9 ft)
SE of a 12-inch diameter red fire main and 6.61 m (21.7 ft) NE of the center of
a 0.76 m (2.5 ft) diameter access cover stamped "electric."
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 5 of 6
Station ID: 2431000 PUBLICATION DATE: 07/12/2016
Name: DIEGO GARCIA, INDIAN OCEAN.
NOAA Chart: Latitude: 7° 17.4' S ( -7.29000)
USGS Quad: Longitude: 72° 23.6' E ( 72.39330)
T I D A L D A T U M S
Tidal datums at DIEGO GARCIA, INDIAN OCEAN. based on:
LENGTH OF SERIES: 1 YEAR
TIME PERIOD: January 1993 - December 1993
TIDAL EPOCH: NONE
CONTROL TIDE STATION:
Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in METERS:
HIGHEST OBSERVED WATER LEVEL (02/19/1992) = 1.889
MEAN HIGHER HIGH WATER MHHW = 1.186
MEAN HIGH WATER MHW = 1.157
MEAN TIDE LEVEL MTL = 0.602
MEAN SEA LEVEL MSL = 0.602
MEAN LOW WATER MLW = 0.047
MEAN LOWER LOW WATER MLLW = 0.000
LOWEST OBSERVED WATER LEVEL (11/23/1995) = -0.440
Bench Mark Elevation Information In METERS above:
Stamping or Designation MLLW MHW
1000 D 1990 4.205 3.048
1000 A 1990 4.039 2.882
1000 B 1990 3.998 2.841
1000 C 1990 4.114 2.957
1000 E 1990 2.574 1.417
1000 F 1990 2.840 1.683
1000 G 1990 3.486 2.329
1000 H 1991 2.575 1.418
1000 J 1991 4.165 3.008
DDW1 EL 10 3.894 2.737
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 6 of 6
Station ID: 2431000 PUBLICATION DATE: 07/12/2016
Name: DIEGO GARCIA, INDIAN OCEAN.
NOAA Chart: Latitude: 7° 17.4' S ( -7.29000)
USGS Quad: Longitude: 72° 23.6' E ( 72.39330)
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 local island datum. 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.
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/.