U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Datums Page Page 1 of 5 Station ID: 8724571 PUBLICATION DATE: 04/21/2003 Name: FLEMING KEY, NORTH END FL NOAA Chart: 11441 Latitude: 24° 35.5' N ( 24.59170) USGS Quad: KEY WEST Longitude: 81° 47.7' W ( -81.79500) To reach the tidal bench marks from the intersection of US Highway 1 and Palm Avenue in Key West, turn right on Palm Avenue and proceed 0.8 km (0.5 mi) to the entrance of Tumbo Point Annex, turn right and go past the guard shack to an intersection, turn left on Chevalier Avenue and proceed to a stop sign, then turn right and continue over a bridge to another stop sign, then turn right and follow the road for 2.7 km (1.7 mi) along the water to the entrance of the Special Forces Under Water Training Facility and the small boat docks on the right. The bench marks are located in the nearby vicinity and the gauge was located on the most northern finger pier. T I D A L B E N C H M A R K S PRIMARY BENCH MARK STAMPING: 4571 A 2001 DESIGNATION: 872 4571 A MONUMENTATION: Tidal Station disk VM#: 16429 AGENCY: National Ocean Service (NOS) IDB PID#: SETTING CLASSIFICATION: Concrete bulkhead OPUS PID#: BBDF80 LATITUDE: 24° 35.5' N ( 24.59170) LONGITUDE: 81° 47.7' W ( -81.79500) The primary bench mark is a disk set flush in a concrete bulkhead on the north side of the small boat dock at the Special Forces Training Center, 20.60 m (67.6 ft) SW of the NE end of the dock, 3.35 m (11.0 ft) SE of the NE corner of the concrete dock, and 0.32 m (1.0 ft) west of the east face of the bulkhead.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 2 of 5 Station ID: 8724571 PUBLICATION DATE: 04/21/2003 Name: FLEMING KEY, NORTH END FL NOAA Chart: 11441 Latitude: 24° 35.5' N ( 24.59170) USGS Quad: KEY WEST Longitude: 81° 47.7' W ( -81.79500) T I D A L B E N C H M A R K S BENCH MARK STAMPING: 4571 B 2001 DESIGNATION: 872 4571 B MONUMENTATION: Tidal Station disk VM#: 16430 AGENCY: National Ocean Service (NOS) IDB PID#: SETTING CLASSIFICATION: Concrete bulkhead OPUS PID#: BBDF81 LATITUDE: 24° 35.5' N ( 24.59170) LONGITUDE: 81° 47.7' W ( -81.79500) The bench mark is a disk set flush in the SE corner of the concrete bulkhead of the small boat dock, 25.80 m (84.6 ft) east of the centerline of the gravel road leading to the dock, 21.46 m (70.4 ft) WSW of the NE corner of the dock, and 3.50 m (11.5 ft) SE of the NW face of the dock. BENCH MARK STAMPING: 4571 C 2001 DESIGNATION: 872 4571 C MONUMENTATION: Tidal Station disk VM#: 16431 AGENCY: National Ocean Service (NOS) IDB PID#: SETTING CLASSIFICATION: Concrete cistern OPUS PID: LATITUDE: 24° 35.5' N ( 24.59170) LONGITUDE: 81° 47.7' W ( -81.79500) The bench mark is set in the NE corner of a 2.2 x 7.3 m (7.2 x 24.0 ft) concrete cistern SE of the small boat docks and near the water and obstacle course, 55.40 m (181.8 ft) NE of the centerline of the paved road leading to base, 30.65 m (100.6 ft) SE of a square concrete pole next to the obstacle course, and 4.51 m (14.8 ft) SW of the waterline.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 3 of 5 Station ID: 8724571 PUBLICATION DATE: 04/21/2003 Name: FLEMING KEY, NORTH END FL NOAA Chart: 11441 Latitude: 24° 35.5' N ( 24.59170) USGS Quad: KEY WEST Longitude: 81° 47.7' W ( -81.79500) T I D A L B E N C H M A R K S BENCH MARK STAMPING: 4571 D 2001 DESIGNATION: 872 4571 D MONUMENTATION: Tidal Station disk VM#: 16432 AGENCY: National Ocean Service (NOS) IDB PID#: SETTING CLASSIFICATION: Concrete pad OPUS PID#: BBDF82 LATITUDE: 24° 35.5' N ( 24.59170) LONGITUDE: 81° 47.7' W ( -81.79500) The bench mark is set flush in the NE corner of a pad for a green electrical transformer, in the grass near the small boat dock, 26.00 m (85.3 ft) SE of the most eastern gate post of the most northern gate, and 13.30 m (43.6 ft) east of the centerline of the paved road leading to base. BENCH MARK STAMPING: 4571 E 2001 DESIGNATION: 872 4571 E MONUMENTATION: Tidal Station disk VM#: 16433 AGENCY: National Ocean Service (NOS) IDB PID#: SETTING CLASSIFICATION: Building foundation OPUS PID: LATITUDE: 24° 35.5' N ( 24.59170) LONGITUDE: 81° 47.7' W ( -81.79500) The bench mark is a disk set flush in a concrete foundation on the south side of Building KW 700, 32.30 m (106.0 ft) NW of a chainlink fence, 20.20 m (66.3 ft) NE of the paved road leading into base, 3.00 m (9.8 ft) SE of the NE corner of the building, and 2.80 m (9.2 ft) ESE of the face of the building.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 4 of 5 Station ID: 8724571 PUBLICATION DATE: 04/21/2003 Name: FLEMING KEY, NORTH END FL NOAA Chart: 11441 Latitude: 24° 35.5' N ( 24.59170) USGS Quad: KEY WEST Longitude: 81° 47.7' W ( -81.79500) T I D A L D A T U M S Tidal datums at FLEMING KEY, NORTH END based on: LENGTH OF SERIES: 2 Months TIME PERIOD: April 2001 - May 2001 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 = 0.443 MEAN HIGH WATER MHW = 0.364 MEAN SEA LEVEL MSL = 0.216 MEAN TIDE LEVEL MTL = 0.211 MEAN LOW WATER MLW = 0.057 MEAN LOWER LOW WATER MLLW = 0.000 North American Vertical Datum (NAVD88) Bench Mark Elevation Information In METERS above: Stamping or Designation MLLW MHW 4571 A 2001 1.065 0.701 4571 B 2001 0.915 0.551 4571 C 2001 1.590 1.226 4571 D 2001 1.447 1.083 4571 E 2001 1.900 1.537
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 5 of 5 Station ID: 8724571 PUBLICATION DATE: 04/21/2003 Name: FLEMING KEY, NORTH END FL NOAA Chart: 11441 Latitude: 24° 35.5' N ( 24.59170) USGS Quad: KEY WEST Longitude: 81° 47.7' W ( -81.79500) 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.