U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Datums Page Page 1 of 5 Station ID: 8724423 PUBLICATION DATE: 02/05/2004 Name: SADDLEBUNCH CHANNEL NO. 5 FL NOAA Chart: 11442 Latitude: 24° 36.7' N ( 24.61170) USGS Quad: SADDLEBUNCH KEYS Longitude: 81° 37.4' W ( -81.62330) To reach the tidal bench marks from the Catholic Church in Key West, proceed 19.2 km (11.9 mi) NE on U.S. Highway 1 to the NE end of the bridge over Saddlebunch Channel No. 5. The bench marks are in the vicinity of the old U.S. Highway 1 bridge (now a fishing pier) and the U.S. Highway 1 bridge. The tide gage and staff were located west of the north wing wall of the old U.S. Highway 1 bridge (fishing pier). T I D A L B E N C H M A R K S PRIMARY BENCH MARK STAMPING: NO 4 1975 DESIGNATION: 872 4423 TIDAL 4 MONUMENTATION: Tidal Station disk VM#: 9599 AGENCY: National Ocean Survey (NOS) IDB PID#: AA0771 SETTING CLASSIFICATION: Concrete footing OPUS PID: LATITUDE: 24° 36.7' N ( 24.61170) LONGITUDE: 81° 37.4' W ( -81.62330) The primary bench mark is a disk set in the concrete footing of the first concrete power pole east of the U.S. Highway 1 bridge over Saddlebunch Channel No. 5, 20 m (64 ft) SE of the centerline of U.S. Highway 1, 0.30 m (1.0 ft) NW of the power pole, and 3 m (9 ft) below U.S. Highway 1.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 2 of 5 Station ID: 8724423 PUBLICATION DATE: 02/05/2004 Name: SADDLEBUNCH CHANNEL NO. 5 FL NOAA Chart: 11442 Latitude: 24° 36.7' N ( 24.61170) USGS Quad: SADDLEBUNCH KEYS Longitude: 81° 37.4' W ( -81.62330) T I D A L B E N C H M A R K S BENCH MARK STAMPING: NO 1 1975 DESIGNATION: 872 4423 TIDAL 1 MONUMENTATION: Tidal Station disk VM#: 9596 AGENCY: National Ocean Survey (NOS) IDB PID#: AA0769 SETTING CLASSIFICATION: Concrete wing wall OPUS PID: LATITUDE: 24° 36.7' N ( 24.61170) LONGITUDE: 81° 37.4' W ( -81.62330) The bench mark is a disk set in the north wing wall located at the NE end of the old U.S. Highway 1 bridge (now a fishing pier), 5 m (15 ft) NW of the centerline of the old U.S. Highway 1 bridge (fishing pier), 5 m (15 ft) west of the NE end of the old bridge (fishing pier) guardrail, 0.76 m (2.5 ft) NW of the NW edge of the old bridge (fishing pier), and 1 m (3 ft) below the roadway. BENCH MARK STAMPING: NO 2 1975 DESIGNATION: 872 4423 TIDAL 2 MONUMENTATION: Tidal Station disk VM#: 9597 AGENCY: National Ocean Survey (NOS) IDB PID#: AA0767 SETTING CLASSIFICATION: Concrete wing wall OPUS PID: LATITUDE: 24° 36.7' N ( 24.61170) LONGITUDE: 81° 37.4' W ( -81.62330) The bench mark is a disk set in the south wing wall located at the NE end of the old U.S. Highway 1 bridge (now a fishing pier), 4 m (14 ft) SE of the centerline of the old U.S. Highway 1 bridge (fishing pier), 0.76 m (2.5 ft) SE of the SE edge of the old bridge (fishing pier), and 1 m (3 ft) below the roadway.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 3 of 5 Station ID: 8724423 PUBLICATION DATE: 02/05/2004 Name: SADDLEBUNCH CHANNEL NO. 5 FL NOAA Chart: 11442 Latitude: 24° 36.7' N ( 24.61170) USGS Quad: SADDLEBUNCH KEYS Longitude: 81° 37.4' W ( -81.62330) T I D A L B E N C H M A R K S BENCH MARK STAMPING: NO 3 1975 DESIGNATION: 872 4423 TIDAL 3 MONUMENTATION: Tidal Station disk VM#: 9598 AGENCY: National Ocean Survey (NOS) IDB PID#: AA0768 SETTING CLASSIFICATION: Concrete wing wall OPUS PID: LATITUDE: 24° 36.7' N ( 24.61170) LONGITUDE: 81° 37.4' W ( -81.62330) The bench mark is a disk set in the south wing wall located at the NE end of the old U.S. Highway 1 bridge (now a fishing pier), 12 m (41 ft) SE of the centerline of the old U.S. Highway 1 bridge (fishing pier), 10.82 m (35.5 ft) SE of the SE edge of the old bridge (fishing pier), and 2 m (7 ft) below the roadway. BENCH MARK STAMPING: 4423 F DESIGNATION: 872 4423 F TIDAL MONUMENTATION: Bench Mark disk VM#: 9600 AGENCY: Florida Department of Transportation (FLDT) IDB PID#: AA0770 SETTING CLASSIFICATION: Concrete bridge guardrail OPUS PID: LATITUDE: 24° 36.7' N ( 24.61170) LONGITUDE: 81° 37.4' W ( -81.62330) The bench mark is a disk set in the concrete guardrail located at the NE end of U.S. Highway 1 bridge over Saddlebunch Channel No. 5, 7.10 m (23.3 ft) SE of the centerline of U.S. Highway 1, 3.11 m (10.2 ft) SW of the NE end of the guardrail, 1.49 m (4.9 ft) NW of the SE bridge cheekwall, 0.30 m (1.0 ft) NE of the abutment, and 1 m (3 ft) above U.S. Highway 1.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 4 of 5 Station ID: 8724423 PUBLICATION DATE: 02/05/2004 Name: SADDLEBUNCH CHANNEL NO. 5 FL NOAA Chart: 11442 Latitude: 24° 36.7' N ( 24.61170) USGS Quad: SADDLEBUNCH KEYS Longitude: 81° 37.4' W ( -81.62330) T I D A L D A T U M S Tidal datums at SADDLEBUNCH CHANNEL NO. 5 based on: LENGTH OF SERIES: 1 MONTH TIME PERIOD: February 1975 - February 1975 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 = 0.388 MEAN HIGH WATER MHW = 0.306 North American Vertical Datum NAVD88 = 0.292 MEAN SEA LEVEL MSL = 0.197 MEAN TIDE LEVEL MTL = 0.193 MEAN LOW WATER MLW = 0.080 MEAN LOWER LOW WATER MLLW = 0.000 North American Vertical Datum (NAVD88) Bench Mark Elevation Information In METERS above: Stamping or Designation MLLW MHW NO 4 1975 0.516 0.210 NO 1 1975 2.445 2.139 NO 2 1975 2.472 2.166 NO 3 1975 0.994 0.688 4423 F 4.203 3.897
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 5 of 5 Station ID: 8724423 PUBLICATION DATE: 02/05/2004 Name: SADDLEBUNCH CHANNEL NO. 5 FL NOAA Chart: 11442 Latitude: 24° 36.7' N ( 24.61170) USGS Quad: SADDLEBUNCH KEYS Longitude: 81° 37.4' W ( -81.62330) 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.