U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Datums Page Page 1 of 5 Station ID: 8667425 PUBLICATION DATE: 02/05/2004 Name: PETERS POINT, ST. PIERRE CREEK SC NOAA Chart: 11522 Latitude: 32° 32.4' N ( 32.54000) USGS Quad: EDISTO ISLAND Longitude: 80° 20.4' W ( -80.34000) To reach the tidal bench marks from the Edisto Island Post Office, proceed south on State Highway 174 for 0.3 km (0.2 mi) to County Road S-10-767 (Peters Point Road). Turn right onto County Road S-10-767 and go west 5.8 km (3.6 mi) to the end of the pavement, then follow the dirt road for 0.3 km (0.2 mi) to a grassy drive leading north to a boat dock. The bench marks are along the sand road and near the dock. The tide gauge and staff were on the dock. T I D A L B E N C H M A R K S PRIMARY BENCH MARK STAMPING: 7425 A 1977 DESIGNATION: 866 7425 A TIDAL MONUMENTATION: Tidal Station disk VM#: 11376 AGENCY: National Ocean Survey (NOS) IDB PID#: CK2522 SETTING CLASSIFICATION: Stainless steel rod OPUS PID: LATITUDE: 32° 32.4' N ( 32.54000) LONGITUDE: 80° 20.3' W ( -80.33830) The primary bench mark is a disk located near the dock, 42.89 m (140.7 ft) north of the SE corner of a large two-story house, 24.17 m (79.3 ft) NNW of power pole #36645, 22.71 m (74.5 ft) NW of a lone 1 m (2 ft) diameter cedar tree with a brick structure at the base, and 8.84 m (29.0 ft) ENE of the centerline of the drive leading to the dock. The bench mark is set level with the ground, crimped to the top of a stainless steel rod driven 11.3 m (37 ft) to refusal, and encased in a PVC pipe and concrete kickblock.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 2 of 5 Station ID: 8667425 PUBLICATION DATE: 02/05/2004 Name: PETERS POINT, ST. PIERRE CREEK SC NOAA Chart: 11522 Latitude: 32° 32.4' N ( 32.54000) USGS Quad: EDISTO ISLAND Longitude: 80° 20.4' W ( -80.34000) T I D A L B E N C H M A R K S BENCH MARK STAMPING: 7425 C 1977 DESIGNATION: 866 7425 C TIDAL MONUMENTATION: Tidal Station disk VM#: 11377 AGENCY: National Ocean Survey (NOS) IDB PID#: CK2521 SETTING CLASSIFICATION: Stainless steel rod OPUS PID: LATITUDE: 32° 32.4' N ( 32.54000) LONGITUDE: 80° 20.3' W ( -80.33830) The bench mark is a disk located at the intersection of the dirt road and the grassy drive leading to the dock, 49.59 m (162.7 ft) ENE of the SE corner of the large two-story house, 30.11 m (98.8 ft) ESE of a lone 1 m (2 ft) diameter cedar tree with a brick structure at the base, 9.72 m (31.9 ft) SSW of a double 1 m (4 ft) diameter oak tree, and 3.69 m (12.1 ft) NNW of the centerline of the dirt road. The bench mark is set level with the ground, crimped to the top of a stainless steel rod driven 7.0 m (23 ft) to refusal, and encased in a PVC pipe and concrete kickblock. BENCH MARK STAMPING: 7425 E 1977 DESIGNATION: 866 7425 E TIDAL MONUMENTATION: Tidal Station disk VM#: 11378 AGENCY: National Ocean Survey (NOS) IDB PID#: CK2520 SETTING CLASSIFICATION: Stainless steel rod OPUS PID: LATITUDE: 32° 32.4' N ( 32.54000) LONGITUDE: 80° 20.2' W ( -80.33670) The bench mark is a disk located at the tip of a timber median between the dirt road and a grassy trail, 79.22 m (259.9 ft) SW of bench mark 7425 G 1983, 5.76 m (18.9 ft) SSE of the approximate center of the overhead power lines, and 3.29 m (10.8 ft) NNW of the centerline of the road. The bench mark is set 0.3 m (1 ft) above road level, crimped to the top of a stainless steel rod driven 7.0 m (23 ft) to refusal, and encased in a PVC pipe and concrete kickblock.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 3 of 5 Station ID: 8667425 PUBLICATION DATE: 02/05/2004 Name: PETERS POINT, ST. PIERRE CREEK SC NOAA Chart: 11522 Latitude: 32° 32.4' N ( 32.54000) USGS Quad: EDISTO ISLAND Longitude: 80° 20.4' W ( -80.34000) T I D A L B E N C H M A R K S BENCH MARK STAMPING: 7425 F 1983 DESIGNATION: 866 7425 F TIDAL MONUMENTATION: Tidal Station disk VM#: 11379 AGENCY: National Ocean Service (NOS) IDB PID#: CK2523 SETTING CLASSIFICATION: Concrete monument OPUS PID: LATITUDE: 32° 32.4' N ( 32.54000) LONGITUDE: 80° 20.3' W ( -80.33830) The bench mark is a disk set in the top of a concrete monument located near a power pole on the south side of the large two-story house, 25.30 m (83.0 ft) SSE of the SE corner of the house, 4.88 m (16.0 ft) WSW of a double trunk 1 m (2 ft) diameter pine tree, 3.66 m (12.0 ft) east of power pole #37648. BENCH MARK STAMPING: 7425 G 1983 DESIGNATION: 866 7425 G TIDAL MONUMENTATION: Tidal Station disk VM#: 11380 AGENCY: National Ocean Service (NOS) IDB PID#: CK2519 SETTING CLASSIFICATION: Concrete monument OPUS PID: LATITUDE: 32° 32.4' N ( 32.54000) LONGITUDE: 80° 20.2' W ( -80.33670) The bench mark is a disk set in the top of a concrete monument located near a power pole at the entrance to the property, 19.39 m (63.6 ft) WSW of the approximate center of the end of pavement, 13.41 m (44.0 ft) NNW of the centerline of the trail, and 1.07 m (3.5 ft) WNW of power pole #18.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 4 of 5 Station ID: 8667425 PUBLICATION DATE: 02/05/2004 Name: PETERS POINT, ST. PIERRE CREEK SC NOAA Chart: 11522 Latitude: 32° 32.4' N ( 32.54000) USGS Quad: EDISTO ISLAND Longitude: 80° 20.4' W ( -80.34000) T I D A L D A T U M S Tidal datums at PETERS POINT, ST. PIERRE CREEK based on: LENGTH OF SERIES: 1 YEAR TIME PERIOD: February 1978 - January 1979 TIDAL EPOCH: 1983-2001 CONTROL TIDE STATION: 8665530 CHARLESTON, COOPER RIVER ENTRANCE Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in METERS: HIGHEST OBSERVED WATER LEVEL (07/19/1978) = 2.525 MEAN HIGHER HIGH WATER MHHW = 2.032 MEAN HIGH WATER MHW = 1.920 North American Vertical Datum NAVD88 = 1.113 MEAN SEA LEVEL MSL = 1.078 MEAN TIDE LEVEL MTL = 0.992 MEAN LOW WATER MLW = 0.065 MEAN LOWER LOW WATER MLLW = 0.000 LOWEST OBSERVED WATER LEVEL (01/09/1978) = -0.986 North American Vertical Datum (NAVD88) Bench Mark Elevation Information In METERS above: Stamping or Designation MLLW MHW 7425 A 1977 5.515 3.595 7425 C 1977 5.257 3.337 7425 E 1977 5.453 3.533 7425 F 1983 5.388 3.468 7425 G 1983 5.483 3.563
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 5 of 5 Station ID: 8667425 PUBLICATION DATE: 02/05/2004 Name: PETERS POINT, ST. PIERRE CREEK SC NOAA Chart: 11522 Latitude: 32° 32.4' N ( 32.54000) USGS Quad: EDISTO ISLAND Longitude: 80° 20.4' W ( -80.34000) 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.