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/.