U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Datums Page Page 1 of 7 Station ID: 8724311 PUBLICATION DATE: 06/28/2004 Name: RACOON KEY FL NOAA Chart: 11448 Latitude: 24° 44.5' N ( 24.74170) USGS Quad: SUMMERLAND KEY Longitude: 81° 29.0' W ( -81.48330) To reach the tidal bench marks from the west end of the bridge between Ramrod Key and Summerland Key, proceed north by boat for 4.3 km (3.1 nm) and then NW for 7.0 km (5.1 nm) to Raccoon Key. The bench marks are located about the middle of the Key and closer to the east shore. The tide gage and staff were located about 0.5 km (0.3 mi) east of the SE shore. 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 7 Station ID: 8724311 PUBLICATION DATE: 06/28/2004 Name: RACOON KEY FL NOAA Chart: 11448 Latitude: 24° 44.5' N ( 24.74170) USGS Quad: SUMMERLAND KEY Longitude: 81° 29.0' W ( -81.48330) T I D A L B E N C H M A R K S PRIMARY BENCH MARK STAMPING: RAC 1935 DESIGNATION: RAC 1935 ALIAS: 3 MONUMENTATION: Triangulation Station disk VM#: 6929 AGENCY: US Coast and Geodetic Survey (USC&GS) IDB PID#: AA1563 SETTING CLASSIFICATION: Concrete monument OPUS PID: LATITUDE: 24° 44.5' N ( 24.74170) LONGITUDE: 81° 29.4' W ( -81.49000) The primary bench mark is a disk set in the top of a 0.24 m (0.8 ft) square concrete monument located 0.40 km (0.25 mi) north of the southern point of the Key, 39.96 m (131.1 ft) SSE of bench mark 4311 F 1984, 37 m (121 ft) inshore of the outer mangroves on the SE shore, and 0.21 m (0.7 ft) above the ground.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 3 of 7 Station ID: 8724311 PUBLICATION DATE: 06/28/2004 Name: RACOON KEY FL NOAA Chart: 11448 Latitude: 24° 44.5' N ( 24.74170) USGS Quad: SUMMERLAND KEY Longitude: 81° 29.0' W ( -81.48330) T I D A L B E N C H M A R K S BENCH MARK STAMPING: RAC 1935 RM NO 1 DESIGNATION: RAC RM 1 ALIAS: 2 MONUMENTATION: Reference Mark disk VM#: 6930 AGENCY: US Coast and Geodetic Survey (USC&GS) IDB PID#: SETTING CLASSIFICATION: Concrete monument OPUS PID: LATITUDE: 24° 44.5' N ( 24.74170) LONGITUDE: 81° 29.0' W ( -81.48330) The bench mark is a disk set in the top of a 0.24 m (0.8 ft) square concrete monument, 26.00 m (85.3 ft) WSW of triangulation station RAC 1935, 0.70 m (2.3 ft) east of a witness post, and 0.21 m (0.7 ft) above the ground.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 4 of 7 Station ID: 8724311 PUBLICATION DATE: 06/28/2004 Name: RACOON KEY FL NOAA Chart: 11448 Latitude: 24° 44.5' N ( 24.74170) USGS Quad: SUMMERLAND KEY Longitude: 81° 29.0' W ( -81.48330) T I D A L B E N C H M A R K S BENCH MARK STAMPING: RAC 1935 RM NO 2 DESIGNATION: RAC RM 2 ALIAS: 1 MONUMENTATION: Reference Mark disk VM#: 6931 AGENCY: US Coast and Geodetic Survey (USC&GS) IDB PID#: SETTING CLASSIFICATION: Concrete monument OPUS PID: LATITUDE: 24° 44.5' N ( 24.74170) LONGITUDE: 81° 29.0' W ( -81.48330) The bench mark is a disk set in the top of a 0.24 m (0.8 ft) square concrete monument, 26.18 m (85.9 ft) NW of triangulation station RAC 1935, 1.31 m (4.3 ft) east of a witness post, and 0.21 m (0.7 ft) above the ground. BENCH MARK STAMPING: NO 4 1974 DESIGNATION: 872 4311 TIDAL 4 MONUMENTATION: Tidal Station disk VM#: 6932 AGENCY: National Ocean Survey (NOS) IDB PID#: SETTING CLASSIFICATION: Copper-clad rod OPUS PID: LATITUDE: 24° 44.5' N ( 24.74170) LONGITUDE: 81° 29.0' W ( -81.48330) The bench mark is a disk located among the mangrove trees, 10.36 m (34.0 ft) ENE of bench mark NO 5 1974, 8 m (25 ft) west of the outer mangrove edge on the east shore, 1.77 m (5.8 ft) north of a witness sign nailed to a tree, and 0.61 m (2.0 ft) WSW of a witness post. The bench mark is set 6 cm (0.2 ft) above the ground, crimped to the top fo a copper-clad rod driven an unspecified depth to refusal.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 5 of 7 Station ID: 8724311 PUBLICATION DATE: 06/28/2004 Name: RACOON KEY FL NOAA Chart: 11448 Latitude: 24° 44.5' N ( 24.74170) USGS Quad: SUMMERLAND KEY Longitude: 81° 29.0' W ( -81.48330) T I D A L B E N C H M A R K S BENCH MARK STAMPING: NO 5 1974 DESIGNATION: 872 4311 TIDAL 5 MONUMENTATION: Tidal Station disk VM#: 6933 AGENCY: National Ocean Survey (NOS) IDB PID#: SETTING CLASSIFICATION: Copper-clad rod OPUS PID: LATITUDE: 24° 44.5' N ( 24.74170) LONGITUDE: 81° 29.0' W ( -81.48330) The bench mark is a disk located at the edge of a clearing, 27.74 m (91.0 ft) east of bench mark RAC 1935 RM NO 2, 20.91 m (68.6 ft) NNE of triangulation station RAC 1935, and 0.67 m (2.2 ft) ENE of a witness post. The bench mark is set 15 cm (0.5 ft) above the ground, crimped to the top of a copper-clad rod driven an unspecified depth to refusal. BENCH MARK STAMPING: 4311 F 1984 DESIGNATION: 872 4311 F TIDAL MONUMENTATION: Tidal Station disk VM#: 6934 AGENCY: National Ocean Service (NOS) IDB PID#: SETTING CLASSIFICATION: Bedrock OPUS PID: LATITUDE: 24° 44.5' N ( 24.74170) LONGITUDE: 81° 29.0' W ( -81.48330) The bench mark is a disk set in concrete poured in a hole in the bedrock, 40 m (131 ft) NW of triangulation station RAC 1935, 31.39 m (103.0 ft) NW of bench mark NO 5 1974, 17.83 m (58.5 ft) NNE of bench mark RAC 1935 RM NO 2, 1.92 m (6.3 ft) ENE of a witness post, and 0.15 m (0.5 ft) above ground level.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 6 of 7 Station ID: 8724311 PUBLICATION DATE: 06/28/2004 Name: RACOON KEY FL NOAA Chart: 11448 Latitude: 24° 44.5' N ( 24.74170) USGS Quad: SUMMERLAND KEY Longitude: 81° 29.0' W ( -81.48330) T I D A L D A T U M S Tidal datums at RACOON KEY based on: LENGTH OF SERIES: 1 MONTH TIME PERIOD: September 1974 - September 1974 TIDAL EPOCH: 1983-2001 CONTROL TIDE STATION: 8724580 KEY WEST Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in METERS: MEAN HIGHER HIGH WATER MHHW = 0.786 MEAN HIGH WATER MHW = 0.696 MEAN TIDE LEVEL MTL = 0.392 MEAN SEA LEVEL MSL = 0.388 MEAN LOW WATER MLW = 0.088 MEAN LOWER LOW WATER MLLW = 0.000 North American Vertical Datum (NAVD88) Bench Mark Elevation Information In METERS above: Stamping or Designation MLLW MHW RAC 1935 1.078 0.382 RAC 1935 RM NO 1 1.098 0.402 RAC 1935 RM NO 2 1.007 0.311 NO 4 1974 0.987 0.291 NO 5 1974 1.023 0.327 4311 F 1984 1.063 0.367
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 7 of 7 Station ID: 8724311 PUBLICATION DATE: 06/28/2004 Name: RACOON KEY FL NOAA Chart: 11448 Latitude: 24° 44.5' N ( 24.74170) USGS Quad: SUMMERLAND KEY Longitude: 81° 29.0' W ( -81.48330) 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.