U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Datums Page Page 1 of 5 PUBLICATION DATE: 02/14/1985 Station ID: 8728786 SUPERCEDED DATE: 04/21/2003 Name: ELEVEN MILE, ST. VINCENT SOUND FLORIDA NOAA Chart: 11401 Latitude: 29° 42.4' N USGS Quad: INDIAN PASS Longitude: 85° 9.2' W To reach the tidal bench marks proceed west along U.S. Highway 98 from Appalachicola, 8.0 miles (12.9 km) to the intersection of U.S. Highway 98 and S 30, continue left along S 30 for for 2.8 miles (4.5 km) to a dirt and oyster shell road at Eleven Mile, then 0.2 mile (0.3 km) to the end of the road and to Eleven Mile Oyster Farm and Store. The bench mark are along S 30 and the road to the boat house, and the tide gage and staff were located on the Eleven Mile Oyster Farm. T I D A L B E N C H M A R K S PRIMARY BENCH MARK STAMPING: 8786 A 1977 MONUMENTATION: Survey Disk VM#: 9884 AGENCY: PID#: AS0872 SETTING CLASSIFICATION: Copper-clad Steel Rod The bench mark is 58.0 feet (17.7 m) SE of the NE corner of the easterly dock, 18.0 feet (5.5 m) ENE of the centerline the dirt road, 6.5 feet (2.0 m) SE of utility pole No. 56X 2661R, and 2 feet (0.6 m) west of a witness post. The bench mark is at ground level, crimped to a copper-clad steel rod driven 48 feet (15 m), and encased in a PVC protector pipe and concrete kickblock. BENCH MARK STAMPING: 8786 B 1977 MONUMENTATION: Survey Disk VM#: 9885 AGENCY: PID#: AS0871 SETTING CLASSIFICATION: Concrete Monument The bench mark is 337 feet (103 m) NW along the dirt road from Bench Mark 8786 A 1977, 77.5 feet (23.6 m) NNW of utility pole No. 6 X 860R with transformer, 45.0 feet (13.7 m) WSW of a 5 feet (2 m) diameter oak, 15.0 feet (4.6 m) west of the centerline of the dirt road, 1.7 feet (0.5 m) SE of a witness post, at ground level, level with the centerline of the road, and set in a concrete monument.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 2 of 5 PUBLICATION DATE: 02/14/1985 Station ID: 8728786 SUPERCEDED DATE: 04/21/2003 Name: ELEVEN MILE, ST. VINCENT SOUND FLORIDA NOAA Chart: 11401 Latitude: 29° 42.4' N USGS Quad: INDIAN PASS Longitude: 85° 9.2' W T I D A L B E N C H M A R K S BENCH MARK STAMPING: 8786 C 1977 MONUMENTATION: Survey Disk VM#: 9886 AGENCY: PID#: AS0870 SETTING CLASSIFICATION: Concrete Monument The bench mark is 296 feet (90 m) north of Bench Mark 8786 B 1977, 42.0 feet (12.8 m) SE of utility pole No. 56X 1859R, 34.0 feet (10.4 m) NW of a 1.5 foot (0.5 m) diameter palm tree, 26.0 feet (7.9 m) ENE of the centerline of the dirt road, 4 feet (1.2 m) WNW of a witness post, at ground level and set in a concrete monument. BENCH MARK STAMPING: 8786 D 1977 MONUMENTATION: Survey Disk VM#: 9887 AGENCY: PID#: AS0869 SETTING CLASSIFICATION: Copper-clad Steel Rod The bench mark is 268 feet (82 m) north of Bench Mark 8766 C 1977, 86.0 feet (26.2 m) SSE of the centerline of Highway S 30, 24.0 feet (7.3 m) ENE of the centerline of the road to Eleven Mile Oyster farm and store, 10.3 feet (3.1 m) WSW of SW corner of abandoned white building, 11.0 feet (3.4 m) NNW of utility pole No. 56X 1790R, and 1.8 feet (0.5 m) WSW of a witness post. The bench mark is at ground level, crimped to a copper-clad steel rod driven 15.5 feet (4.7 m), and encased in a PVC protector pipe and concrete kickblock.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 3 of 5 PUBLICATION DATE: 02/14/1985 Station ID: 8728786 SUPERCEDED DATE: 04/21/2003 Name: ELEVEN MILE, ST. VINCENT SOUND FLORIDA NOAA Chart: 11401 Latitude: 29° 42.4' N USGS Quad: INDIAN PASS Longitude: 85° 9.2' W T I D A L B E N C H M A R K S BENCH MARK STAMPING: 8786 E 1977 MONUMENTATION: Survey Disk VM#: 9888 AGENCY: PID#: AS0520 SETTING CLASSIFICATION: Concrete Monument The bench mark is NE of Bench Mark 8786 D 1977, 193.0 feet (58.8 m) east of Eleven Mile Farm dirt road, 38.6 feet (11.8 m) NNW of the centerline of Highway S 30, 22.0 feet (6.7 m) SE of a witness post, at ground level, 1 foot (0.3 m) below the centerline of the highway and set in a concrete monument.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 4 of 5 PUBLICATION DATE: 02/14/1985 Station ID: 8728786 SUPERCEDED DATE: 04/21/2003 Name: ELEVEN MILE, ST. VINCENT SOUND FLORIDA NOAA Chart: 11401 Latitude: 29° 42.4' N USGS Quad: INDIAN PASS Longitude: 85° 9.2' W T I D A L D A T U M S Tidal datums at ELEVEN MILE, ST. VINCENT SOUND based on: LENGTH OF SERIES: 6 MONTHS TIME PERIOD: DECEMBER 1977 - MAY 1978 TIDAL EPOCH: 1960-1978 CONTROL TIDE STATION: 8729840 PENSACOLA Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in FEET: HIGHEST OBSERVED WATER LEVEL (05/04/1978) = 2.91 MEAN HIGHER HIGH WATER MHHW = 1.69 MEAN HIGH WATER MHW = 1.55 MEAN TIDE LEVEL MTL = 0.99 MEAN LOW WATER MLW = 0.43 MEAN LOWER LOW WATER MLLW = 0.00 LOWEST OBSERVED WATER LEVEL (02/22/1985) = -1.71 North American Vertical Datum (NAVD88) Bench Mark Elevation Information In FEET above: Stamping or Designation MLLW MHW 8786 A 1977 3.43 1.88 8786 B 1977 6.65 5.10 8786 C 1977 5.78 4.23 8786 D 1977 7.90 6.35 8786 E 1977 10.23 8.68
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 5 of 5 PUBLICATION DATE: 02/14/1985 Station ID: 8728786 SUPERCEDED DATE: 04/21/2003 Name: ELEVEN MILE, ST. VINCENT SOUND FLORIDA NOAA Chart: 11401 Latitude: 29° 42.4' N USGS Quad: INDIAN PASS Longitude: 85° 9.2' 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.