U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Datums Page Page 1 of 5 PUBLICATION DATE: 06/12/1984 Station ID: 8729943 SUPERCEDED DATE: 04/21/2003 Name: HURST HAMMOCK, PERDIDO RIVER FLORIDA NOAA Chart: 11382 Latitude: 30° 27.5' N USGS Quad: LILLIAN Longitude: 87° 24.5' W To reach the tidal bench marks from the intersection of U.S. Highway 90 and Beaulah Road, proceed south on Beaulah Road for 2.4 miles (3.9 km) to a fork in the road, follow right fork (Hurst Hammock Road) for 3.1 miles (5.0 km) south to the roads end, continue east on the dirt road at the end of Hurst Hammock Road for 560 feet (171 m) to a fenced property on the Perdido River. The bench marks are located along Hurst Hammock Road and the dirt road and the tide gage and staff were located on a dock behind the private residence. T I D A L B E N C H M A R K S PRIMARY BENCH MARK STAMPING: 9943 A 1977 MONUMENTATION: Survey Disk VM#: 10312 AGENCY: PID#: BG4597 SETTING CLASSIFICATION: Galvanized Steel Rod The bench mark is 300 feet (91 m) east of Bench Mark 9943 B 1977, 19.8 feet (6.0 m) south of the dirt road that continues from the end of Hurst Hammock Road, 13.9 feet (4.2 m) east of the centerline of dirt drive leading to the private residence, and 3.7 feet (1.1 m) east of the NE corner of the fence that surrounds the property. The bench mark is 0.4 foot (0.1 m) below ground level, crimped to a galvanized steel rod driven 40 feet (12 m) and encased in a PVC pipe and concrete kickblock. BENCH MARK STAMPING: 9943 B 1977 MONUMENTATION: Survey Disk VM#: 10313 AGENCY: PID#: BG4596 SETTING CLASSIFICATION: Galvanized Steel Rod The bench mark is 300 feet (91 m) west of Bench Mark 9943 A 1977, 263 feet (80 m) east of Bench Mark 9943 C 1977, 14.8 feet (4.5 m) south of the dirt road at the end of Hurst Hammock Road, 5.4 feet (1.6 m) NE of the NW corner of the fence which surrounds the private property and 2.9 feet (0.9 m) east of a power pole with a witness sign. The bench mark is 0.4 foot (0.1 m) below ground level, cirmped to a galvanized steel rod driven 40 feet (12 m), 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and Atmospheric Administration National Ocean Service Page 2 of 5 PUBLICATION DATE: 06/12/1984 Station ID: 8729943 SUPERCEDED DATE: 04/21/2003 Name: HURST HAMMOCK, PERDIDO RIVER FLORIDA NOAA Chart: 11382 Latitude: 30° 27.5' N USGS Quad: LILLIAN Longitude: 87° 24.5' W T I D A L B E N C H M A R K S BENCH MARK STAMPING: 9943 C 1977 MONUMENTATION: Survey Disk VM#: 10314 AGENCY: PID#: BG4595 SETTING CLASSIFICATION: Galvanized Steel Rod The bench mark is 262 feet (80 m) SE of Bench Mark 9943 D 1977, 24.4 feet (7.4 m) west of the point of the intersection of Hurst Hammock Road and the dirt road at the end of Hurst Hammock Road, and 5.1 feet (1.6 m) north of power pole #0834054257 with a witness sign. The bench mark is 0.3 foot (0.1 m) below ground level, crimped to a galvanized steel rod driven 40 feet (12 m), and encased in a PVC pipe and concrete kickblock. BENCH MARK STAMPING: 9943 D 1977 MONUMENTATION: Survey Disk VM#: 10315 AGENCY: PID#: BG4594 SETTING CLASSIFICATION: Galvanized Steel Rod The bench mark is 46.5 feet (14.2 m) SSE of the SE corner of the last residence on the west side of Hurst Hammock Road, 35 feet (11 m) north of the north bank of a tidal creek, 32 feet (10 m) west of the centerline of Hurst Hammock Road, and 3.6 feet (1.1 m) south of lighted power pole #833654277 with a witness sign. The bench mark is level with the ground, crimped to a galvanized steel rod driven 40 feet (12 m), 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 PUBLICATION DATE: 06/12/1984 Station ID: 8729943 SUPERCEDED DATE: 04/21/2003 Name: HURST HAMMOCK, PERDIDO RIVER FLORIDA NOAA Chart: 11382 Latitude: 30° 27.5' N USGS Quad: LILLIAN Longitude: 87° 24.5' W T I D A L B E N C H M A R K S BENCH MARK STAMPING: 9943 E 1977 MONUMENTATION: Survey Disk VM#: 10316 AGENCY: PID#: BG4593 SETTING CLASSIFICATION: Galvanized Steel Rod The bench mark is 380 feet (116 m) north of Bench Mark 9943 D 1977, 46.9 feet (14.3 m) east of the SE corner of a fenced residence, 28.6 feet (8.7 m) west of the centerline of Hurst Hammock Road, and 8.6 feet (2.6 m) north of a lighted power pole with a witness sign. The bench mark is 0.3 foot (0.1 m) below ground level, crimped to a galvanized steel rod driven 40 feet (12 m), 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 PUBLICATION DATE: 06/12/1984 Station ID: 8729943 SUPERCEDED DATE: 04/21/2003 Name: HURST HAMMOCK, PERDIDO RIVER FLORIDA NOAA Chart: 11382 Latitude: 30° 27.5' N USGS Quad: LILLIAN Longitude: 87° 24.5' W T I D A L D A T U M S Tidal datums at HURST HAMMOCK, PERDIDO RIVER based on: LENGTH OF SERIES: 1 MONTH TIME PERIOD: JULY 1977 TIDAL EPOCH: 1960-1978 CONTROL TIDE STATION: 8729962 PERDIDO BAY Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in FEET: HIGHEST OBSERVED WATER LEVEL (04/22/1977) = 1.91 MEAN HIGHER HIGH WATER MHHW = 0.78 MEAN HIGH WATER MHW = 0.76 MEAN TIDE LEVEL MTL = 0.41 MEAN LOW WATER MLW = 0.06 MEAN LOWER LOW WATER MLLW = 0.00 LOWEST OBSERVED WATER LEVEL (03/23/1977) = -0.93 North American Vertical Datum (NAVD88) Bench Mark Elevation Information In FEET above: Stamping or Designation MLLW MHW 9943 A 1977 4.39 3.63 9943 B 1977 8.26 7.50 9943 C 1977 11.27 10.51 9943 D 1977 3.33 2.57 9943 E 1977 3.73 2.97
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 5 of 5 PUBLICATION DATE: 06/12/1984 Station ID: 8729943 SUPERCEDED DATE: 04/21/2003 Name: HURST HAMMOCK, PERDIDO RIVER FLORIDA NOAA Chart: 11382 Latitude: 30° 27.5' N USGS Quad: LILLIAN Longitude: 87° 24.5' 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 (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 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.