U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Datums Page Page 1 of 10 Station ID: 9761115 PUBLICATION DATE: 03/05/2013 Name: BARBUDA NOAA Chart: 25570 Latitude: 17° 35.4' N ( 17.59069) USGS Quad: Longitude: 61° 49.2' W ( -61.82056) To reach the tide station from the intersection of Top Mission Street and River Road in the village of Codrington, proceed south on River Road for 3.7 km (2.3 mi) to the end of the asphalt. Continue south on River Road, now dirt, for 1.8 km (1.1 mi) to the fork in the road. Bear to the right (through an open chain link fence gate) and proceed 0.3 km (0.2 mi) to a "T" intersection. Turn WSW (right) and proceed 0.2 km (0.1 mi) to the River Wharf and the tide station on the left. The bench marks are located in the vicinity of the tide station, with the majority of the marks in a line running NW to SE. T I D A L B E N C H M A R K S PRIMARY BENCH MARK STAMPING: 1115 A 2011 DESIGNATION: 976 1115 A MONUMENTATION: Survey disk VM#: 20085 AGENCY: National Ocean Service IDB PID#: SETTING CLASSIFICATION: Set in concrete footing OPUS PID: LATITUDE: 17° 35.4' N ( 17.59067) LONGITUDE: 61° 49.2' W ( -61.82056) The primary bench mark is a brass disk set flush in the SW concrete footing for the tide station, 18.20 m (59.8 ft) east of the center of the SE side of a bridge over two culverts, 9.70 m (31.9 ft) SE of the center of the road, 0.30 m (1.0 ft) NE of the SW edge of the SW footing, 0.29 m (0.95 ft) SW of the NE edge of the SW footing, 0.26 m (0.85 ft) NW from the SE end of the SW footing, and 0.28 m (0.9 ft) SE of the SE face of the tide station's SW leg.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 2 of 10 Station ID: 9761115 PUBLICATION DATE: 03/05/2013 Name: BARBUDA NOAA Chart: 25570 Latitude: 17° 35.4' N ( 17.59069) USGS Quad: Longitude: 61° 49.2' W ( -61.82056) T I D A L B E N C H M A R K S BENCH MARK STAMPING: 1115 B 2011 DESIGNATION: 976 1115 B MONUMENTATION: Flange-encased Rod VM#: 20086 AGENCY: National Ocean Service IDB PID#: SETTING CLASSIFICATION: OPUS PID: LATITUDE: 17° 35.5' N ( 17.59119) LONGITUDE: 61° 49.2' W ( -61.82006) The bench mark is a flange-encased rod located 43.6 m (143.0 ft) NE of the third phone pole SW of River Road, 18.0 m (59.2 ft) SE from the center of the concrete company's equipment yard's SW gate, 1.70 m (5.7 ft) SW of the second phone pole SW of River Road, 0.60 m (2.0 ft) NW of an orange fiberglass witness post, 0.26 m (0.85 ft) below the road surface, and 0.03 m (0.1 ft) below ground level. The datum point is the top of a stainless steel rod driven 1.67 m (5.5 ft) to refusal, and encased in a 13 cm (5 inches) PVC pipe with concrete kick block.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 3 of 10 Station ID: 9761115 PUBLICATION DATE: 03/05/2013 Name: BARBUDA NOAA Chart: 25570 Latitude: 17° 35.4' N ( 17.59069) USGS Quad: Longitude: 61° 49.2' W ( -61.82056) T I D A L B E N C H M A R K S BENCH MARK STAMPING: 1115 C 2011 DESIGNATION: 976 1115 C MONUMENTATION: Flange-encased Rod VM#: 20087 AGENCY: National Ocean Service IDB PID#: SETTING CLASSIFICATION: OPUS PID: LATITUDE: 17° 35.5' N ( 17.59092) LONGITUDE: 61° 49.2' W ( -61.81961) The bench mark is a flange-encased rod located at the top of the beach on the SE side of the entrance road to the river wharf, NNW of the SW end of a chain link fence, near where the sand meets the grass, 98.90 m (324.5 ft) NW of bench mark 976 1115 D, 26.60 m (87.4 ft) NE of the normal high water mark along the beach, 0.80 m (2.75 ft) NNW of a fence post and the SW end of a fence running NE to SW, 0.60 m (2.0 ft) SW of an orange fiberglass witness post, and 0.10 m (0.34 ft) above ground level. The datum point is the top of a stainless steel rod driven 3.13 m (10.3 ft) to refusal, and encased in a 13 cm (5 inches) PVC pipe with concrete kick block. BENCH MARK STAMPING: 1115 D 2011 DESIGNATION: 976 1115 D MONUMENTATION: Survey disk VM#: 20088 AGENCY: National Ocean Service IDB PID#: SETTING CLASSIFICATION: Set in rock outcrop OPUS PID: LATITUDE: 17° 35.4' N ( 17.59050) LONGITUDE: 61° 49.1' W ( -61.81878) The bench mark is a brass disk set flush in the NW end of a rock outcrop along the water, SE of the beach on the SE side of the entrance road to the River Wharf, 98.90 m (324.5 ft) SE of benchmark 976 1115 C, 68.90 m (226.0 ft) NW of benchmark 976 1115 E, 66.70 m (218.8 ft) west of a wire fence that runs parallel to a dirt road, and 5.70 m (18.7 ft) east of the west edge of a pointy rock above the water.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 4 of 10 Station ID: 9761115 PUBLICATION DATE: 03/05/2013 Name: BARBUDA NOAA Chart: 25570 Latitude: 17° 35.4' N ( 17.59069) USGS Quad: Longitude: 61° 49.2' W ( -61.82056) T I D A L B E N C H M A R K S BENCH MARK STAMPING: 1115 E 2011 DESIGNATION: 976 1115 E MONUMENTATION: Survey disk VM#: 20089 AGENCY: National Ocean Service IDB PID#: SETTING CLASSIFICATION: Set in rock outcrop OPUS PID: LATITUDE: 17° 35.4' N ( 17.59000) LONGITUDE: 61° 49.1' W ( -61.81839) The bench mark is a brass disk set flush in a rock outcrop along the water and SE of the beach on the SE side of the entrance road to the River Wharf, 82.40 m (270.5 ft) NW of benchmark 976 1115 F, 68.90 m (226.0 ft) SE of benchmark 976 1115 D, 58.90 m (193.4 ft) WSW of a wire fence that runs parallel to a dirt road, and 3.50 m (11.6 ft) WSW of the intersection where the rock outcrop and grass meet. BENCH MARK STAMPING: 1115 F 2011 DESIGNATION: 976 1115 F MONUMENTATION: Survey disk VM#: 20090 AGENCY: National Ocean Service IDB PID#: SETTING CLASSIFICATION: Set in rock outcrop OPUS PID: LATITUDE: 17° 35.4' N ( 17.58950) LONGITUDE: 61° 49.1' W ( -61.81783) The bench mark is a brass disk set flush in a rock outcrop along the water and SE of the beach on the SE side of the entrance road to the River Wharf, 82.30 m (270.5 ft) SE of bench mark 976 1115 E, 18.00 m (59.15 ft) NNW of the NW corner of a concrete block foundation built on the rock outcrop next to the water's edge, and 3.30 m (10.7 ft) SW of the intersection where the rock outcrop and grass meet.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 5 of 10 Station ID: 9761115 PUBLICATION DATE: 03/05/2013 Name: BARBUDA NOAA Chart: 25570 Latitude: 17° 35.4' N ( 17.59069) USGS Quad: Longitude: 61° 49.2' W ( -61.82056) T I D A L B E N C H M A R K S BENCH MARK STAMPING: 1115 G 2011 DESIGNATION: 976 1115 G MONUMENTATION: Survey disk VM#: 20091 AGENCY: IDB PID#: SETTING CLASSIFICATION: Set in concrete filled bollard OPUS PID: LATITUDE: 17° 35.5' N ( 17.59158) LONGITUDE: 61° 49.2' W ( -61.82083) The bench mark is a brass disk located SW of the access road that runs NW/SE along the beach and ends at the 'T' intersection, 35.30 m (115.8 ft) SE of bench mark 976 1115 H, 23.60 m (77.4 ft) north of a 1.70 m (5.7 ft) high concrete block pillar used as a bollard to secure boats to, 12.10 m (39.8 ft) SW of the chain link fence along the concrete company's equipment yard's SW side, and 24 cm (9 inches) above the ground level. The benchmark is set flush in the top of a 25 cm (10 inch) diameter concrete and metal-encased bollard.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 6 of 10 Station ID: 9761115 PUBLICATION DATE: 03/05/2013 Name: BARBUDA NOAA Chart: 25570 Latitude: 17° 35.4' N ( 17.59069) USGS Quad: Longitude: 61° 49.2' W ( -61.82056) T I D A L B E N C H M A R K S BENCH MARK STAMPING: 1115 H 2011 DESIGNATION: 976 1115 H MONUMENTATION: Survey disk VM#: 20092 AGENCY: National Ocean Service IDB PID#: SETTING CLASSIFICATION: Set in concrete filled bollard OPUS PID: LATITUDE: 17° 35.5' N ( 17.59181) LONGITUDE: 61° 49.3' W ( -61.82108) The bench mark is a brass disk located SW of the access road that runs NW/SE along the beach and ends at the 'T' intersection, 35.30 m (115.8 ft) NW of bench mark 976 1115 G, 28.00 m (91.85 ft) SE of the concrete company's fence corner where the fence turns NNE (the corner is NW of the NW entrance gate along the access road (across from the beach) to the concrete company's equipment yard), 6.80 m (22.45 ft) SW of the chain link fence around the equipment yard, and 0.70 m (2.4 ft) above the ground/concrete foundation level. The benchmark is set flush in the top of a 0.40 m (1.25 ft) diameter concrete and metal-encased bollard with an axle passing through the top center (to tie the rope to), that is set in a 1.5 m x 2.0 m concrete foundation.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 7 of 10 Station ID: 9761115 PUBLICATION DATE: 03/05/2013 Name: BARBUDA NOAA Chart: 25570 Latitude: 17° 35.4' N ( 17.59069) USGS Quad: Longitude: 61° 49.2' W ( -61.82056) T I D A L B E N C H M A R K S BENCH MARK STAMPING: 1115 J 2011 DESIGNATION: 976 1115 J MONUMENTATION: Flange-encased Rod VM#: 20093 AGENCY: IDB PID#: SETTING CLASSIFICATION: OPUS PID: LATITUDE: 17° 35.5' N ( 17.59206) LONGITUDE: 61° 49.3' W ( -61.82167) The bench mark is a flange-encased rod located along the SW edge of the access road leading to the River Wharf, 47.50 m (155.8 ft) SE of the NE gate post that separates river road with the NW end of the access road that leads to the River Wharf, 40.70 m (133.6 ft) WNW of the concrete company's fence corner where the fence turns NNE (the corner is NW of the NW entrance gate along the access road (across from the beach) to the concrete company's equipment yard), 5.15 m (16.9 ft) SSW of the center of the dirt access road connecting River Road with the entrance to the River Wharf, 1.25 m (4.1 ft) NE of an orange fiberglass witness post, and 6 cm (2 inches) below ground level. The datum point is the top of a stainless steel rod driven 4.23 m (13.9 ft) to refusal, and encased in a 13 cm (5 inches) PVC pipe with concrete kick block.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 8 of 10 Station ID: 9761115 PUBLICATION DATE: 03/05/2013 Name: BARBUDA NOAA Chart: 25570 Latitude: 17° 35.4' N ( 17.59069) USGS Quad: Longitude: 61° 49.2' W ( -61.82056) T I D A L B E N C H M A R K S BENCH MARK STAMPING: 1115 K 2011 DESIGNATION: 976 1115 K MONUMENTATION: Flange-encased Rod VM#: 20094 AGENCY: National Ocean Service IDB PID#: SETTING CLASSIFICATION: OPUS PID: LATITUDE: 17° 35.5' N ( 17.59236) LONGITUDE: 61° 49.3' W ( -61.82219) The bench mark is a flange-encased rod located 22.20 m (72.8 ft) east of a 0.90 m (3.0 ft) diameter palm tree at its base, the tallest and southernmost of three palm trees in a row, 21.70 m (71.2 ft) WNW of the NE gate post that separates river road with the NW end of the access road leading to the River Wharf, 7.90 m (25.9 ft) SW of the intersection of River Road and the access road that leads to the River Wharf, 0.90 m (3.0 ft) NE of an orange fiberglass witness post, and 14 cm (6 inches) below the ground surface. The datum point is the top of a stainless steel rod driven 6.75 m (22.1 ft) to refusal, and encased in a 13 cm (5 inches) PVC pipe with concrete kick block.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 9 of 10 Station ID: 9761115 PUBLICATION DATE: 03/05/2013 Name: BARBUDA NOAA Chart: 25570 Latitude: 17° 35.4' N ( 17.59069) USGS Quad: Longitude: 61° 49.2' W ( -61.82056) T I D A L D A T U M S Tidal datums at BARBUDA based on: LENGTH OF SERIES: 1 YEAR TIME PERIOD: July 2011 - June 2012 TIDAL EPOCH: 1983-2001 CONTROL TIDE STATION: 9751401 LIME TREE BAY, ST CROIX Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in METERS: HIGHEST OBSERVED WATER LEVEL (08/23/2012) = 0.545 MEAN HIGHER HIGH WATER MHHW = 0.225 MEAN HIGH WATER MHW = 0.219 MEAN SEA LEVEL MSL = 0.133 MEAN TIDE LEVEL MTL = 0.127 MEAN LOW WATER MLW = 0.035 MEAN LOWER LOW WATER MLLW = 0.000 LOWEST OBSERVED WATER LEVEL (12/25/2011) = -0.177 North American Vertical Datum (NAVD88) Bench Mark Elevation Information In METERS above: Stamping or Designation MLLW MHW 1115 A 2011 1.468 1.249 1115 B 2011 1.144 0.925 1115 C 2011 1.344 1.125 1115 D 2011 1.687 1.468 1115 E 2011 2.262 2.043 1115 F 2011 1.713 1.494 1115 G 2011 1.803 1.584 1115 H 2011 2.425 2.206 1115 J 2011 1.663 1.444 1115 K 2011 1.036 0.817
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 10 of 10 Station ID: 9761115 PUBLICATION DATE: 03/05/2013 Name: BARBUDA NOAA Chart: 25570 Latitude: 17° 35.4' N ( 17.59069) USGS Quad: Longitude: 61° 49.2' W ( -61.82056) 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 the fixed datums of North American Vertical Datum of 1988 (NAVD88). NAVD88 is a fixed datum derived from a simultaneous, least squares, minimum constraint adjustment of Canadian/Mexican/United States leveling observations. Local mean sea level observed at Father Point/Rimouski, Canada was held fixed as the single initial constraint. NAVD88 replaces NGVD29 as the national standard geodetic reference for heights. Bench mark elevations relative to NAVD88 are available from NGS through the World Wide Web at National Geodetic Survey. NGVD29 is a fixed datum adopted as a national standard geodetic reference for heights but is now considered superseded. NGVD29 is sometimes referred to as Sea Level Datum of 1929 or as Mean Sea Level on some early issues of Geological Survey Topographic Quads. NGVD29 was originally derived from a general adjustment of the first-order leveling networks of the U.S. and Canada after holding mean sea level observed at 26 long term tide stations as fixed. Numerous local and wide-spread adjustments have been made since establishment in 1929. Bench mark elevations relative to NGVD29 are available from the National Geodetic Survey (NGS) data base via the World Wide Web at National Geodetic Survey. NAVD88 and NGVD29 are fixed geodetic datums whose elevation relationships 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/. The NAVD88 elevation is shown on the Elevations of Tidal Datums Table Referred to MLLW only when two or more of the bench marks listed have NAVD88 elevations. The NAVD88 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, NAVD88 bench mark elevations computed indirectly from the tidal datums elevation table may differ slightly from NAVD88 elevations listed for each bench mark in the NGS database.