U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Datums Page Page 1 of 6 Station ID: 8630308 PUBLICATION DATE: 07/12/2004 Name: CHINCOTEAGUE CHANNEL, SOUTH END VA NOAA Chart: 12211 Latitude: 37° 54.4' N ( 37.90670) USGS Quad: CHINCOTEAGUE EAST Longitude: 75° 24.3' W ( -75.40500) To reach the tidal bench marks from Chincoteague at the junction of Main Street and State Highway 175, proceed south along Main Street (State Road 2114) for 3.8 km (2.4 mi) to Mr. Minnicks lot, on the west side of Main Street. The tide gage and staff were located on the north side of the southernmost of two boat slips at Mr. Minnicks lot. T I D A L B E N C H M A R K S PRIMARY BENCH MARK STAMPING: 863 0308 B 1977 DESIGNATION: 863 0308 B TIDAL MONUMENTATION: Tidal Station disk VM#: 3260 AGENCY: National Ocean Survey (NOS) IDB PID#: SETTING CLASSIFICATION: Concrete monument OPUS PID: LATITUDE: 37° 54.4' N ( 37.90670) LONGITUDE: 75° 24.3' W ( -75.40500) The primary bench mark is a disk set in a concrete monument, 41.61 m (136.5 ft) SE of bench mark 863 0308 A 1977, 22.25 m (73.0 ft) NW of the north corner of Mr. Minnicks trailer, 0.67 m (2.2 ft) NE of the east corner of a block foundation and at ground level. BENCH MARK STAMPING: 863 0308 A 1977 DESIGNATION: 863 0308 A TIDAL MONUMENTATION: Tidal Station disk VM#: 3259 AGENCY: National Ocean Survey (NOS) IDB PID#: SETTING CLASSIFICATION: Concrete monument OPUS PID: LATITUDE: 37° 54.4' N ( 37.90670) LONGITUDE: 75° 24.3' W ( -75.40500) The bench mark is a disk set in a concrete monument in the back of Mr. Minnick's lot near the north line, 41.61 m (136.5 ft) NW of bench mark 863 0308 B 1977, 7.41 m (24.3 ft) east of the north corner of a shop, 6.46 m (21.2 ft) NE of the east corner of the shop and at ground level.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 2 of 6 Station ID: 8630308 PUBLICATION DATE: 07/12/2004 Name: CHINCOTEAGUE CHANNEL, SOUTH END VA NOAA Chart: 12211 Latitude: 37° 54.4' N ( 37.90670) USGS Quad: CHINCOTEAGUE EAST Longitude: 75° 24.3' W ( -75.40500) T I D A L B E N C H M A R K S BENCH MARK STAMPING: 863 0308 C 1977 DESIGNATION: 863 0308 C TIDAL MONUMENTATION: Tidal Station disk VM#: 3261 AGENCY: National Ocean Survey (NOS) IDB PID#: SETTING CLASSIFICATION: Concrete monument OPUS PID#: BBDY44 LATITUDE: 37° 54.4' N ( 37.90670) LONGITUDE: 75° 24.3' W ( -75.40500) The bench mark is a disk set in concrete, near the southeastern part of a large parking lot, 58.06 m (190.5 ft) NE of the east corner of Mr. Minnick's trailer, 48 m (156 ft) NW of the centerline of the road, 4.72 m (15.5 ft) SE of a power pole and at ground level.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 3 of 6 Station ID: 8630308 PUBLICATION DATE: 07/12/2004 Name: CHINCOTEAGUE CHANNEL, SOUTH END VA NOAA Chart: 12211 Latitude: 37° 54.4' N ( 37.90670) USGS Quad: CHINCOTEAGUE EAST Longitude: 75° 24.3' W ( -75.40500) T I D A L B E N C H M A R K S BENCH MARK STAMPING: NO 2 1962 DESIGNATION: TIDAL 2 STA 5 MONUMENTATION: Tidal Station disk VM#: 3262 AGENCY: US Coast & Geodetic Survey (USC&GS) IDB PID#: FW0142 SETTING CLASSIFICATION: Concrete-filled terra cotta pipe OPUS PID: LATITUDE: 37° 54.3' N ( 37.90500) LONGITUDE: 75° 24.4' W ( -75.40670) The bench mark is a disk set in the top of a concrete filled terra cotta pipe, 70 m (230 ft) east of the centerline of Main Street at a side road entrance, 65 m (212 ft) east of power pole ESPSC of Virginia 17 with transformer, 26 m (86 ft) SSE of the fourth USCG telephone pole, 19 m (63 ft) NNW of the third USCG telephone pole and 0.15 m (0.5 ft) above ground level. NOTE: For the complete leveling record for this mark, see station 863-0316, Harbor of Refuge.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 4 of 6 Station ID: 8630308 PUBLICATION DATE: 07/12/2004 Name: CHINCOTEAGUE CHANNEL, SOUTH END VA NOAA Chart: 12211 Latitude: 37° 54.4' N ( 37.90670) USGS Quad: CHINCOTEAGUE EAST Longitude: 75° 24.3' W ( -75.40500) T I D A L B E N C H M A R K S BENCH MARK STAMPING: NO 3 1962 DESIGNATION: TIDAL 3 STA 5 MONUMENTATION: Tidal Station disk VM#: 3263 AGENCY: US Coast & Geodetic Survey (USC&GS) IDB PID#: FW0143 SETTING CLASSIFICATION: Concrete-filled terra cotta pipe OPUS PID: LATITUDE: 37° 54.3' N ( 37.90500) LONGITUDE: 75° 24.4' W ( -75.40670) The bench mark is a disk set in the top of a concrete filled terra cotta pipe, 69 m (225 ft) NNW of bench mark No 2 1962, 43 m (140 ft) SE of power pole ESPSC of Virginia (the first pole north of the pole with a transformer attached), 38 m (126 ft) west of the fifth USCG telephone pole from the south end of the island and 30 m (100 ft) north of the middle of three one-room cottages. NOTE: For the complete leveling record for this mark, see station 863-0316, Harbor of Refuge.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 5 of 6 Station ID: 8630308 PUBLICATION DATE: 07/12/2004 Name: CHINCOTEAGUE CHANNEL, SOUTH END VA NOAA Chart: 12211 Latitude: 37° 54.4' N ( 37.90670) USGS Quad: CHINCOTEAGUE EAST Longitude: 75° 24.3' W ( -75.40500) T I D A L D A T U M S Tidal datums at CHINCOTEAGUE CHANNEL, SOUTH END based on: LENGTH OF SERIES: 3 MONTHS TIME PERIOD: June 1977 - August 1977 TIDAL EPOCH: 1983-2001 CONTROL TIDE STATION: 8630249 CHINCOTEAGUE, USCG STATION Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in METERS: MEAN HIGHER HIGH WATER MHHW = 0.758 MEAN HIGH WATER MHW = 0.691 North American Vertical Datum NAVD88 = 0.401 MEAN TIDE LEVEL MTL = 0.362 MEAN SEA LEVEL MSL = 0.359 MEAN LOW WATER MLW = 0.033 MEAN LOWER LOW WATER MLLW = 0.000 North American Vertical Datum (NAVD88) Bench Mark Elevation Information In METERS above: Stamping or Designation MLLW MHW 863 0308 B 1977 1.380 0.689 863 0308 A 1977 1.564 0.873 863 0308 C 1977 1.606 0.915 NO 2 1962 1.427 0.736 NO 3 1962 1.252 0.561
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 6 of 6 Station ID: 8630308 PUBLICATION DATE: 07/12/2004 Name: CHINCOTEAGUE CHANNEL, SOUTH END VA NOAA Chart: 12211 Latitude: 37° 54.4' N ( 37.90670) USGS Quad: CHINCOTEAGUE EAST Longitude: 75° 24.3' W ( -75.40500) 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.