U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Datums Page Page 1 of 5 Station ID: 8664801 PUBLICATION DATE: 02/05/2004 Name: PRICE CREEK SC NOAA Chart: 11521 Latitude: 32° 52.9' N ( 32.88170) USGS Quad: SEWEE BAY Longitude: 79° 39.5' W ( -79.65830) To reach the tidal bench marks from a boat landing at Breach Inlet at the south end of Isle of Palms, proceed by boat north on Hamlin Creek to the Intracoastal Waterway at black can buoy 117, then proceed NE on the Intracoastal Waterway for about 16.7 km (10.4 statute mi) to a flashing red light (4 second) on a fixed structure marked 86, then turn right and go about 2.7 km (1.7 statute mi) SE on Price Creek to Magwoods dock on the west bank of the creek. The bench marks are along the foot path leading from the dock to the Magwood residence. The tide gage and staff were at the end of the dock. T I D A L B E N C H M A R K S PRIMARY BENCH MARK STAMPING: MD NO 2 1975 DESIGNATION: 866 4801 MD TIDAL 2 MONUMENTATION: Tidal Station disk VM#: 4100 AGENCY: National Ocean Survey (NOS) IDB PID#: SETTING CLASSIFICATION: Copper-clad steel rod OPUS PID: LATITUDE: 32° 52.9' N ( 32.88170) LONGITUDE: 79° 39.5' W ( -79.65830) The primary bench mark is a disk located along the foot path to the Magwood residence, 30 m (98 ft) SW of bench mark MD NO 1 1975, 17.01 m (55.8 ft) SW of a 2-inch metal post at the SW corner of a wooden open shed, 2.50 m (8.2 ft) north of a utility pole, 2.32 m (7.6 ft) SE of the centerline of the path, 2.13 m (7.0 ft) west of a lone myrtle bush, and 0.27 m (0.9 ft) NW of a witness post with sign. The bench mark is set 3 cm (0.1 ft) above ground level, crimped to the top of a copper-clad steel rod driven an unspecified depth 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: 8664801 PUBLICATION DATE: 02/05/2004 Name: PRICE CREEK SC NOAA Chart: 11521 Latitude: 32° 52.9' N ( 32.88170) USGS Quad: SEWEE BAY Longitude: 79° 39.5' W ( -79.65830) T I D A L B E N C H M A R K S BENCH MARK STAMPING: MD NO 3 1975 DESIGNATION: 866 4801 MD TIDAL 3 MONUMENTATION: Tidal Station disk VM#: 4101 AGENCY: National Ocean Survey (NOS) IDB PID#: SETTING CLASSIFICATION: Copper-clad steel rod OPUS PID: LATITUDE: 32° 52.9' N ( 32.88170) LONGITUDE: 79° 39.5' W ( -79.65830) The bench mark is a disk located a along the foot path to the Magwood residence, 24 m (79 ft) WNW of bench mark MD NO 2 1975, 11.34 m (37.2 ft) ENE of the SE porch piling of a small cabin, 11.06 m (36.3 ft) NW of a utility pole, 7.41 m (24.3 ft) east of the northeasternmost of three cedar trees, 5.91 m (19.4 ft) west of the centerline of the path, and 0.37 m (1.2 ft) NW of a witness post with sign. The bench mark is set at ground level, crimped to the top of a copper-clad steel rod driven an unspecified depth to refusal, and encased in a PVC pipe and concrete kickblock. BENCH MARK STAMPING: MD NO 4 1975 DESIGNATION: 866 4801 MD TIDAL 4 MONUMENTATION: Tidal Station disk VM#: 4102 AGENCY: National Ocean Survey (NOS) IDB PID#: SETTING CLASSIFICATION: Copper-clad steel rod OPUS PID: LATITUDE: 32° 52.9' N ( 32.88170) LONGITUDE: 79° 39.5' W ( -79.65830) The bench mark is a disk located along the foot path to the Magwood residence, 18 m (60 ft) SSW of bench mark MD NO 3 1975, 8.81 m (28.9 ft) NW of the corner of a wooden fence, 8 m (25 ft) NW of the centerline of the foot path, 1.71 m (5.6 ft) NE of a 0.46 m (1.5 ft) diameter oak tree, and 0.40 m (1.3 ft) NNW of a witness post with sign. The bench mark is set 12 cm (0.4 ft) above ground level, crimped to the top of a copper-clad steel rod driven an unspecified depth to refusal, and encased in a 5-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: 8664801 PUBLICATION DATE: 02/05/2004 Name: PRICE CREEK SC NOAA Chart: 11521 Latitude: 32° 52.9' N ( 32.88170) USGS Quad: SEWEE BAY Longitude: 79° 39.5' W ( -79.65830) T I D A L B E N C H M A R K S BENCH MARK STAMPING: MD NO 5 1975 DESIGNATION: 866 4801 MD TIDAL 5 MONUMENTATION: Tidal Station disk VM#: 4103 AGENCY: National Ocean Survey (NOS) IDB PID#: SETTING CLASSIFICATION: Copper-clad steel rod OPUS PID: LATITUDE: 32° 52.9' N ( 32.88170) LONGITUDE: 79° 39.5' W ( -79.65830) The bench mark is a disk located in the vicinity of the Magwood residence, about 59 m (195 ft) south of bench mark MD NO 4 1975, 8.53 m (28.0 ft) SW of the west corner of a cabin, 7.74 m (25.4 ft) SE of the SE corner of an old chimney used as a footing for the house, and 5.55 m (18.2 ft) SSE of a utility pole. The bench mark is set 6 cm (0.2 ft) above the ground, crimped to the top of a copper-clad steel rod driven an unspecified depth 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 4 of 5 Station ID: 8664801 PUBLICATION DATE: 02/05/2004 Name: PRICE CREEK SC NOAA Chart: 11521 Latitude: 32° 52.9' N ( 32.88170) USGS Quad: SEWEE BAY Longitude: 79° 39.5' W ( -79.65830) T I D A L D A T U M S Tidal datums at PRICE CREEK based on: LENGTH OF SERIES: 9 MONTHS TIME PERIOD: July 1976 - March 1977 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: MEAN HIGHER HIGH WATER MHHW = 1.630 MEAN HIGH WATER MHW = 1.514 MEAN SEA LEVEL MSL = 0.792 MEAN TIDE LEVEL MTL = 0.783 MEAN LOW WATER MLW = 0.052 MEAN LOWER LOW WATER MLLW = 0.000 North American Vertical Datum (NAVD88) Bench Mark Elevation Information In METERS above: Stamping or Designation MLLW MHW MD NO 2 1975 2.182 0.668 MD NO 3 1975 2.227 0.713 MD NO 4 1975 2.459 0.945 MD NO 5 1975 2.197 0.683
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 5 of 5 Station ID: 8664801 PUBLICATION DATE: 02/05/2004 Name: PRICE CREEK SC NOAA Chart: 11521 Latitude: 32° 52.9' N ( 32.88170) USGS Quad: SEWEE BAY Longitude: 79° 39.5' W ( -79.65830) 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.