U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Datums Page Page 1 of 5 Station ID: 8669133 PUBLICATION DATE: 02/05/2004 Name: SKULL CREEK SOUTH SOUTH CAROLINA NOAA Chart: 11516 Latitude: 32° 13.4' N USGS Quad: BLUFFTON Longitude: 80° 46.3' W To reach the tidal bench marks from the intersection of U.S. Highway 46 and Calhoun Street (S-7-11) in Bluffton, proceed east, then north on U.S. Highway 46 for 3.1 km (1.9 mi), then turn right and proceed SE on U.S. Highway 278 for 6.6 km (4.1 mi), then turn left and proceed north on Jenkins Island Road (S-7-298) for 0.6 km (0.4 mi) to the dead end in the Hilton Head Harbor Marina parking lot. The tidal bench marks are along the paved road and parking lot. The tide gage and staff were on the north side of the pier behind the convenience store and tackle shop. T I D A L B E N C H M A R K S PRIMARY BENCH MARK STAMPING: 9133 C 1978 DESIGNATION: 866 9133 C TIDAL MONUMENTATION: Tidal Station disk VM#: 4553 AGENCY: National Ocean Survey (NOS) PID#: CK2037 SETTING CLASSIFICATION: Galvanized steel rod The primary bench mark is a disk located along the north side of the paved road near the marina, 31 m (101 ft) SE of the SW end of the narrow part of a wooden dock, 25.09 m (82.3 ft) ENE of an unnumbered service pole leading to the sales office of Outdoor Resorts, 10.21 m (33.5 ft) NE of the centerline of the paved road, 1.98 m (6.5 ft) SSW of power pole #SPC 51-5-85 with transformer, 1.83 m (6.0 ft) SSW of a 0.61 m (2.0 ft) diameter palmetto tree, and 1.34 m (4.4 ft) south of a metal witness post. The bench mark is crimped to the top of a galvanized steel rod driven 8.5 m (28 ft) to refusal, and encased in a PVC pipe and a concrete kickblock. NOTE: The bench mark was not found in 1996.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 2 of 5 Station ID: 8669133 PUBLICATION DATE: 02/05/2004 Name: SKULL CREEK SOUTH SOUTH CAROLINA NOAA Chart: 11516 Latitude: 32° 13.4' N USGS Quad: BLUFFTON Longitude: 80° 46.3' W T I D A L B E N C H M A R K S BENCH MARK STAMPING: 9133 E 1978 DESIGNATION: 866 9133 E TIDAL MONUMENTATION: Tidal Station disk VM#: 4554 AGENCY: National Ocean Survey (NOS) PID#: CK2035 SETTING CLASSIFICATION: Galvanized steel rod The bench mark is a disk located on the east side of the paved road leading to the marina, 8.90 m (29.2 ft) SW of power pole #11-80-SPP-8H-5-35 with transformer 10-H, 8.84 m (29.0 ft) NW of a 0.52 m (1.7 ft) diameter palmetto tree, 6.31 m (20.7 ft) south of a twin trunk tree with a low Y at the base, 5.94 m (19.5 ft) NE of the centerline of the paved road, 5.79 m (19.0 ft) north of a South Carolina Highway Department sign stating ROAD ENDS, 1.52 m (5.0 ft) west of the edge of the maintained shoulder, and 0.27 m (0.9 ft) west of a metal witness post. The bench mark is crimped to the top of a galvanized steel rod driven 8.5 m (28 ft) to refusal, and encased in a PVC pipe and a concrete kickblock. NOTE: The bench mark was not found in 1996. BENCH MARK STAMPING: 9133 F 1981 DESIGNATION: 866 9133 F TIDAL MONUMENTATION: Tidal Station disk VM#: 4555 AGENCY: National Ocean Survey (NOS) PID#: CK2036 SETTING CLASSIFICATION: Concrete monument The bench mark is a disk set in a concrete monument in the center of a landscaped traffic island between a boat storage shed and the marina sales office, 47.40 m (155.5 ft) SW of the west corner railing of a large wooden fishing pier, 21 m (69 ft) east of the NE corner of the boat storage shed, 17.80 m (58.4 ft) SW of the SW corner of the Outdoors Resort Sales Office trailer, 6.61 m (21.7 ft) SSE of the NW end of the landscaped traffic island, 4.11 m (13.5 ft) SE of a 1 m (3 ft) diameter oak tree, 3.35 m (11.0 ft) NW of a 0.61 m (2.0 ft) diameter palmetto tree, 3.32 m (10.9 ft) SE of the perpendicular curb of the landscaped traffic island, 3.26 m (10.7 ft) NW of the perpendicular curb of the landscaped traffic island, and 0.06 m (0.2 ft) above grade.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 3 of 5 Station ID: 8669133 PUBLICATION DATE: 02/05/2004 Name: SKULL CREEK SOUTH SOUTH CAROLINA NOAA Chart: 11516 Latitude: 32° 13.4' N USGS Quad: BLUFFTON Longitude: 80° 46.3' W T I D A L B E N C H M A R K S BENCH MARK STAMPING: 9133 G 1981 DESIGNATION: 866 9133 G TIDAL MONUMENTATION: Tidal Station disk VM#: 4556 AGENCY: National Ocean Survey (NOS) PID#: CK2033 SETTING CLASSIFICATION: Concrete monument The bench mark is a disk set in a concrete monument at the intersection of the paved road and U.S. Highway 278, 27.55 m (90.4 ft) WNW of the centerline of the paved road, 16.31 m (53.5 ft) north of the centerline of the westbound lane of U.S. Highway 278, 10.52 m (34.5 ft) west of a 0.61 m (2.0 ft) diameter pine tree with a square blaze, 1.22 m (4.0 ft) NNE of power pole #EB 479-SPPH 535, 0.52 m (1.7 ft) west of a metal witness post, and at ground level. BENCH MARK STAMPING: 9133 J 1981 DESIGNATION: 866 9133 J TIDAL MONUMENTATION: Tidal Station disk VM#: 4557 AGENCY: National Ocean Survey (NOS) PID#: CK2034 SETTING CLASSIFICATION: Galvanized steel rod The bench mark is a disk located on the east side of the road leading to the marina near the most southerly pole of a major power line, 22.31 m (73.2 ft) SE of the centerline of the paved road, 15.03 m (49.3 ft) NNE of a 0.37 m (1.2 ft) diameter elm tree with a square blase, 4.66 m (15.3 ft) NE of the easternmost 0.40 m (1.3 ft) creosoted pile of a dual pile power line structure, 0.85 m (2.8 ft) WNW of the westernmost pile of a dual pile power line structure, and 0.43 m (1.4 ft) north of a metal witness post. The bench mark is set 0.03 m (0.1 ft) below grade, crimped to the top of a galvanized steel rod driven 14.6 m (48 ft), 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: 8669133 PUBLICATION DATE: 02/05/2004 Name: SKULL CREEK SOUTH SOUTH CAROLINA NOAA Chart: 11516 Latitude: 32° 13.4' N USGS Quad: BLUFFTON Longitude: 80° 46.3' W T I D A L D A T U M S Tidal datums at SKULL CREEK SOUTH based on: LENGTH OF SERIES: 1 YEAR TIME PERIOD: May 1978 - April 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 (09/04/1979) = 3.265 MEAN HIGHER HIGH WATER (MHHW) = 2.408 MEAN HIGH WATER (MHW) = 2.287 NORTH AMERICAN VERTICAL DATUM-1988 (NAVD) = 1.344 MEAN SEA LEVEL (MSL) = 1.270 MEAN TIDE LEVEL (MTL) = 1.178 MEAN LOW WATER (MLW) = 0.069 MEAN LOWER LOW WATER (MLLW) = 0.000 LOWEST OBSERVED WATER LEVEL (04/27/1979) = -1.106 National Geodetic Vertical Datum (NGVD 29) Bench Mark Elevation Information In METERS above: Stamping or Designation MLLW MHW 9133 C 1978 4.139 1.852 9133 E 1978 3.893 1.606 9133 F 1981 4.506 2.219 9133 G 1981 6.355 4.068 9133 J 1981 5.577 3.290
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 5 of 5 Station ID: 8669133 PUBLICATION DATE: 02/05/2004 Name: SKULL CREEK SOUTH SOUTH CAROLINA NOAA Chart: 11516 Latitude: 32° 13.4' N USGS Quad: BLUFFTON Longitude: 80° 46.3' W 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 (NAVD 88). NGVD 29 is a fixed datum adopted as a national standard geodetic reference for heights but is now considered superseded. NGVD 29 is sometimes referred to as Sea Level Datum of 1929 or as Mean Sea Level on some early issues of Geological Survey Topographic Quads. NGVD 29 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 NGVD 29 are available from the National Geodetic Survey (NGS) data base via the World Wide Web at National Geodetic Survey. NAVD 88 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. NAVD 88 replaces NGVD 29 as the national standard geodetic reference for heights. Bench mark elevations relative to NAVD 88 are available from NGS through the World Wide Web at National Geodetic Survey. NGVD 29 and NAVD 88 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 NAVD 88 elevation is shown on the Elevations of Tidal Datums Table Referred to MLLW only when two or more of the bench marks listed have NAVD 88 elevations. The NAVD 88 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, NAVD 88 bench mark elevations computed indirectly from the tidal datums elevation table may differ slightly from NAVD 88 elevations listed for each bench mark in the NGS database.