U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Datums Page Page 1 of 5 Station ID: 8656937 PUBLICATION DATE: 10/15/2004 Name: CAPE LOOKOUT, ATLANTIC OCEAN NC NOAA Chart: 11545 Latitude: 34° 36.5' N ( 34.60830) USGS Quad: CAPE LOOKOUT Longitude: 76° 31.7' W ( -76.52830) To reach the tidal bench marks from Shell Point on Harkers Island, proceed by boat SSW for about 7.4 km (4.0 nm) through Barden Inlet to the Cape Lookout Lighthouse. The bench marks are about 1.3 km (0.8 mi) SSW of the lighthouse, 1.0 km (0.6 mi) NNE of the Coast Guard Station, and 152 m (500 ft) SE of a line of utility poles. The tide gage and staff were SE of bench mark 6937 A 1977, 122 m (400 ft) seaward of the approximate low water line. T I D A L B E N C H M A R K S PRIMARY BENCH MARK STAMPING: 6937 A 1977 DESIGNATION: 865 6937 A MONUMENTATION: Tidal Station disk VM#: 3575 AGENCY: National Ocean Survey (NOS) IDB PID#: SETTING CLASSIFICATION: Galvanized steel rod OPUS PID: LATITUDE: 34° 36.5' N ( 34.60830) LONGITUDE: 76° 31.7' W ( -76.52830) The primary bench mark is a disk located ENE of the Coast Guard Station, 97.96 m (321.4 ft) NE of bench mark 6937 B 1977, 55 m (180 ft) WNW of the berm line, and 0.30 m (1.0 ft) west of a witness post. The bench mark is set 6 cm (0.2 ft) above the ground, crimped to the top of a galvanized steel rod driven 19.5 m (64 ft) to refusal, and encased in a 4-inch PVC pipe and concrete kickblock.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 2 of 5 Station ID: 8656937 PUBLICATION DATE: 10/15/2004 Name: CAPE LOOKOUT, ATLANTIC OCEAN NC NOAA Chart: 11545 Latitude: 34° 36.5' N ( 34.60830) USGS Quad: CAPE LOOKOUT Longitude: 76° 31.7' W ( -76.52830) T I D A L B E N C H M A R K S BENCH MARK STAMPING: 6937 B 1977 DESIGNATION: 865 6937 B MONUMENTATION: Tidal Station disk VM#: 3576 AGENCY: National Ocean Survey (NOS) IDB PID#: SETTING CLASSIFICATION: Galvanized steel rod OPUS PID: LATITUDE: 34° 36.5' N ( 34.60830) LONGITUDE: 76° 31.7' W ( -76.52830) The bench mark is a disk located ENE of the Coast Guard Station, 82.54 m (270.8 ft) south of bench mark 6937 C 1977, and 0.30 m (1.0 ft) west of a witness post. The bench mark is set 6 cm (0.2 ft) above the ground, crimped to the top of a galvanized steel rod driven 17.1 m (56 ft) to refusal, and encased in a 4-inch PVC pipe and concrete kickblock. BENCH MARK STAMPING: 6937 C 1977 DESIGNATION: 865 6937 C MONUMENTATION: Tidal Station disk VM#: 3577 AGENCY: National Ocean Survey (NOS) IDB PID#: SETTING CLASSIFICATION: Galvanized steel rod OPUS PID: LATITUDE: 34° 36.5' N ( 34.60830) LONGITUDE: 76° 31.7' W ( -76.52830) The bench mark is a disk located ENE of the Coast Guard Station, 76.17 m (249.9 ft) SSW of bench mark 6937 D 1977, and 0.30 m (1.0 ft) west of a witness post. The bench mark is set 6 cm (0.2 ft) above the ground, crimped to the top of a galvanized steel rod driven 14.6 m (48 ft) to refusal, and encased in a 4-inch PVC pipe and concrete kickblock.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 3 of 5 Station ID: 8656937 PUBLICATION DATE: 10/15/2004 Name: CAPE LOOKOUT, ATLANTIC OCEAN NC NOAA Chart: 11545 Latitude: 34° 36.5' N ( 34.60830) USGS Quad: CAPE LOOKOUT Longitude: 76° 31.7' W ( -76.52830) T I D A L B E N C H M A R K S BENCH MARK STAMPING: 6937 D 1977 DESIGNATION: 865 6937 D MONUMENTATION: Tidal Station disk VM#: 3578 AGENCY: National Ocean Survey (NOS) IDB PID#: SETTING CLASSIFICATION: Galvanized steel rod OPUS PID: LATITUDE: 34° 36.5' N ( 34.60830) LONGITUDE: 76° 31.7' W ( -76.52830) The bench mark is a disk located ENE of the Coast Guard Station, 82.11 m (269.4 ft) SSW of bench mark 6937 E 1977, and 0.30 m (1.0 ft) west of a witness post. The bench mark is set 6 cm (0.2 ft) above the ground, crimped to the top of a galvanized steel rod driven 14.6 m (48 ft) to refusal, and encased in a 4-inch PVC pipe and concrete kickblock. BENCH MARK STAMPING: 6937 E 1977 DESIGNATION: 865 6937 E MONUMENTATION: Tidal Station disk VM#: 3579 AGENCY: National Ocean Survey (NOS) IDB PID#: SETTING CLASSIFICATION: Galvanized steel rod OPUS PID: LATITUDE: 34° 36.5' N ( 34.60830) LONGITUDE: 76° 31.7' W ( -76.52830) The bench mark is a disk located ENE of the Coast Guard Station, 158 m (519 ft) SE of power pole # 736 which is the 24th power pole south of the lighthouse, 6 m (20 ft) south of the centerline of a 4-wheel drive vehicle trail, and 0.30 m (1.0 ft) west of a witness post. The bench mark is set 6 cm (0.2 ft) above the ground, crimpedto the top of a galvanized steel rod driven 12.2 m (40 ft) to refusal, and encased in a 4-inch PVC pipe and concrete kickblock.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 4 of 5 Station ID: 8656937 PUBLICATION DATE: 10/15/2004 Name: CAPE LOOKOUT, ATLANTIC OCEAN NC NOAA Chart: 11545 Latitude: 34° 36.5' N ( 34.60830) USGS Quad: CAPE LOOKOUT Longitude: 76° 31.7' W ( -76.52830) T I D A L D A T U M S Tidal datums at CAPE LOOKOUT, ATLANTIC OCEAN based on: LENGTH OF SERIES: 8 MONTHS TIME PERIOD: December 1978 - July 1979 TIDAL EPOCH: 1983-2001 CONTROL TIDE STATION: 8656483 BEAUFORT, DUKE MARINE LAB Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in METERS: MEAN HIGHER HIGH WATER MHHW = 1.201 MEAN HIGH WATER MHW = 1.092 MEAN SEA LEVEL MSL = 0.572 MEAN TIDE LEVEL MTL = 0.569 MEAN LOW WATER MLW = 0.045 MEAN LOWER LOW WATER MLLW = 0.000 North American Vertical Datum (NAVD88) Bench Mark Elevation Information In METERS above: Stamping or Designation MLLW MHW 6937 A 1977 2.153 1.061 6937 B 1977 1.792 0.700 6937 C 1977 1.647 0.555 6937 D 1977 1.642 0.550 6937 E 1977 1.837 0.745
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 5 of 5 Station ID: 8656937 PUBLICATION DATE: 10/15/2004 Name: CAPE LOOKOUT, ATLANTIC OCEAN NC NOAA Chart: 11545 Latitude: 34° 36.5' N ( 34.60830) USGS Quad: CAPE LOOKOUT Longitude: 76° 31.7' W ( -76.52830) 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.