U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Datums Page Page 1 of 5 Station ID: 8724378 PUBLICATION DATE: 02/08/2005 Name: PERKY, SUGARLOAF SOUND FL NOAA Chart: 11445 Latitude: 24° 38.9' N ( 24.64830) USGS Quad: SUGARLOAF KEY Longitude: 81° 34.2' W ( -81.57000) To reach the tidal bench marks from the junction of U.S. Highway 1 and State Highway 939 in the village of Perky, proceed west on U.S. Highway 1 for 0.08 km (0.05 mi) to the side road on the right, turn right and continue north for 0.6 km (0.4 mi) to buildings, a small airport and a pond. The bench marks are located at the pond and observation towers. The tide gage and staff were located on a jetty east of the pond. T I D A L B E N C H M A R K S
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 2 of 5 Station ID: 8724378 PUBLICATION DATE: 02/08/2005 Name: PERKY, SUGARLOAF SOUND FL NOAA Chart: 11445 Latitude: 24° 38.9' N ( 24.64830) USGS Quad: SUGARLOAF KEY Longitude: 81° 34.2' W ( -81.57000) T I D A L B E N C H M A R K S PRIMARY BENCH MARK STAMPING: V 271 1966 DESIGNATION: V 271 MONUMENTATION: Bench Mark disk VM#: 7048 AGENCY: US Coast and Geodetic Survey (USC&GS) IDB PID#: AA0129 SETTING CLASSIFICATION: Tower base OPUS PID: LATITUDE: 24° 38.9' N ( 24.64830) LONGITUDE: 81° 34.3' W ( -81.57170) The primary bench mark is a disk set vertically in the SE face of the south base of an observation tower which is part of a large frame house, 32 m (106 ft) NE of the centerline of the private road leading to the airport, and 1 m (2 ft) above the ground.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 3 of 5 Station ID: 8724378 PUBLICATION DATE: 02/08/2005 Name: PERKY, SUGARLOAF SOUND FL NOAA Chart: 11445 Latitude: 24° 38.9' N ( 24.64830) USGS Quad: SUGARLOAF KEY Longitude: 81° 34.2' W ( -81.57000) T I D A L B E N C H M A R K S BENCH MARK STAMPING: PERKY SW BASE AZ MARK 1935 DESIGNATION: PERKY SW BASE AZ MK MONUMENTATION: Reference Mark disk VM#: 7047 AGENCY: US Coast and Geodetic Survey (USC&GS) IDB PID#: AA0130 SETTING CLASSIFICATION: Concrete base OPUS PID: LATITUDE: 24° 39.0' N ( 24.65000) LONGITUDE: 81° 34.4' W ( -81.57330) The bench mark is a disk set in the top of the east side of a 1 m (4 ft) square concrete base supporting the south wooden leg of a 9 m (30 ft) high wooden tower, about 161 m (528 ft) NW of a frame house with an observation tower, and about level with the ground. BENCH MARK STAMPING: NO 1 1974 DESIGNATION: 872 4378 TIDAL 1 MONUMENTATION: Tidal Station disk VM#: 7049 AGENCY: National Ocean Survey (NOS) IDB PID#: AA0729 SETTING CLASSIFICATION: Concrete sea wall OPUS PID: LATITUDE: 24° 38.9' N ( 24.64830) LONGITUDE: 81° 34.2' W ( -81.57000) The bench mark is a disk set in a concrete seawall, 8 m (26 ft) SE of the NW corner of a pond, 8 m (26 ft) NE of the centerline of a road, 7.16 m (23.5 ft) NW of a turn in a road near the SW corner of the pond, and level with the ground.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 4 of 5 Station ID: 8724378 PUBLICATION DATE: 02/08/2005 Name: PERKY, SUGARLOAF SOUND FL NOAA Chart: 11445 Latitude: 24° 38.9' N ( 24.64830) USGS Quad: SUGARLOAF KEY Longitude: 81° 34.2' W ( -81.57000) T I D A L D A T U M S Tidal datums at PERKY, SUGARLOAF SOUND based on: LENGTH OF SERIES: 2 MONTHS TIME PERIOD: April 1974 - May 1974 TIDAL EPOCH: 1983-2001 CONTROL TIDE STATION: 8724580 KEY WEST Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in METERS: North American Vertical Datum NAVD88 = 0.185 MEAN HIGHER HIGH WATER MHHW = 0.178 MEAN HIGH WATER MHW = 0.131 MEAN TIDE LEVEL MTL = 0.069 MEAN SEA LEVEL MSL = 0.061 MEAN LOW WATER MLW = 0.006 MEAN LOWER LOW WATER MLLW = 0.000 North American Vertical Datum (NAVD88) Bench Mark Elevation Information In METERS above: Stamping or Designation MLLW MHW V 271 1966 1.440 1.309 PERKY SW BASE AZ MARK 1935 0.399 0.268 NO 1 1974 0.438 0.307
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 5 of 5 Station ID: 8724378 PUBLICATION DATE: 02/08/2005 Name: PERKY, SUGARLOAF SOUND FL NOAA Chart: 11445 Latitude: 24° 38.9' N ( 24.64830) USGS Quad: SUGARLOAF KEY Longitude: 81° 34.2' W ( -81.57000) 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.