U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Datums Page Page 1 of 6 Station ID: 8724405 PUBLICATION DATE: 01/06/2004 Name: SADDLEBUNCH CHANNEL NO. 3 FL NOAA Chart: 11442 Latitude: 24° 37.4' N ( 24.62330) USGS Quad: SUGARLOAF KEY Longitude: 81° 36.2' W ( -81.60330) To reach the tidal bench marks from the Catholic Church in Key West, proceed 21.7 km (13.5 mi) NE on U.S. Highway 1 to the NE end of the bridge over Saddlebunch Key, Channel No. 3. The bench marks are in the vicinity of old U.S. Highway 1 bridge (now a fishing pier). The tide gage and staff were located on the NE wing wall of the NE end of the old bridge (fishing pier). T I D A L B E N C H M A R K S PRIMARY BENCH MARK STAMPING: NO 1 1975 DESIGNATION: 872 4405 TIDAL 1 MONUMENTATION: Tidal Station disk VM#: 7816 AGENCY: National Ocean Survey (NOS) IDB PID#: AA0774 SETTING CLASSIFICATION: Concrete wing wall OPUS PID: LATITUDE: 24° 37.4' N ( 24.62330) LONGITUDE: 81° 36.2' W ( -81.60330) The primary bench mark is a disk set flush in the north concrete wing wall of the old U.S. Highway 1 bridge (now a fishing pier), 5 m (15 ft) NW of the centerline of the old bridge (fishing pier), and 1 m (3 ft) below the old bridge (fishing pier).
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 2 of 6 Station ID: 8724405 PUBLICATION DATE: 01/06/2004 Name: SADDLEBUNCH CHANNEL NO. 3 FL NOAA Chart: 11442 Latitude: 24° 37.4' N ( 24.62330) USGS Quad: SUGARLOAF KEY Longitude: 81° 36.2' W ( -81.60330) T I D A L B E N C H M A R K S BENCH MARK STAMPING: NO 2 1975 DESIGNATION: 872 4405 TIDAL 2 MONUMENTATION: Tidal Station disk VM#: 7817 AGENCY: National Ocean Survey (NOS) IDB PID#: AA0773 SETTING CLASSIFICATION: Concrete wing wall OPUS PID: LATITUDE: 24° 37.4' N ( 24.62330) LONGITUDE: 81° 36.2' W ( -81.60330) The bench mark is a disk set flush in the south concrete wing wall of the old U.S. Highway 1 bridge (now a fishing pier), 9.30 m (30.5 ft) SE of bench mark NO 1 1975, 4.72 m (15.5 ft) SE of the centerline of the old bridge (fishing pier), 4.11 m (13.5 ft) SW of a sign FAP 107-C, 1.07 m (3.5 ft) SE of the SE edge of the old bridge (fishing pier), and 0.30 m (1.0 ft) below the old bridge (fishing pier). BENCH MARK STAMPING: NO 3 1975 DESIGNATION: 872 4405 TIDAL 3 MONUMENTATION: Tidal Station disk VM#: 7818 AGENCY: National Ocean Survey (NOS) IDB PID#: AA0776 SETTING CLASSIFICATION: Concrete footing OPUS PID: LATITUDE: 24° 37.4' N ( 24.62330) LONGITUDE: 81° 36.2' W ( -81.60330) The bench mark is a disk set flush in the NW corner of the concrete footing of concrete power pole T 741, 25 m (81 ft) NE of bench mark NO 2 1975, 12.95 m (42.5 ft) SE of the extended centerline of the old bridge (now a fishing pier), and 2 m (6 ft) below the old bridge (fishing pier).
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 3 of 6 Station ID: 8724405 PUBLICATION DATE: 01/06/2004 Name: SADDLEBUNCH CHANNEL NO. 3 FL NOAA Chart: 11442 Latitude: 24° 37.4' N ( 24.62330) USGS Quad: SUGARLOAF KEY Longitude: 81° 36.2' W ( -81.60330) T I D A L B E N C H M A R K S BENCH MARK STAMPING: NO 4 1975 DESIGNATION: 872 4405 TIDAL 4 MONUMENTATION: Tidal Station disk VM#: 7819 AGENCY: National Ocean Survey (NOS) IDB PID#: AA0777 SETTING CLASSIFICATION: Copper-clad steel rod OPUS PID: LATITUDE: 24° 37.4' N ( 24.62330) LONGITUDE: 81° 36.2' W ( -81.60330) The bench mark is a disk located 7 m (22 ft) SE of the centerline of Blue Water Drive, and 0.30 m (1.0 ft) NW of a wooden telephone pole. The bench mark is 0.15 m (0.05 ft) above ground, crimped to the top of a cooper-coated steel rod driven an unspecified depth to refusal, encased in a PVC pipe and concrete kickblock. BENCH MARK STAMPING: NO 5 1975 DESIGNATION: 872 4405 TIDAL 5 MONUMENTATION: Tidal Station disk VM#: 7820 AGENCY: National Ocean Survey (NOS) IDB PID#: SETTING CLASSIFICATION: Concrete footing OPUS PID: LATITUDE: 24° 37.4' N ( 24.62330) LONGITUDE: 81° 36.2' W ( -81.60330) The bench mark is a disk set flush at the NW corner of the concrete base of concrete telephone pole No. TT 1-47, 33 m (108 ft) north of bench mark NO 4 1975, 9 m (29 ft) SW of the centerline of Blue Water Drive, and 8 m (25 ft) SE of U.S. Highway 1.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 4 of 6 Station ID: 8724405 PUBLICATION DATE: 01/06/2004 Name: SADDLEBUNCH CHANNEL NO. 3 FL NOAA Chart: 11442 Latitude: 24° 37.4' N ( 24.62330) USGS Quad: SUGARLOAF KEY Longitude: 81° 36.2' W ( -81.60330) T I D A L B E N C H M A R K S BENCH MARK STAMPING: 4405 F DESIGNATION: 872 4405 F TIDAL MONUMENTATION: Survey disk VM#: 7821 AGENCY: Florida Department of Transportation (FLDT) IDB PID#: AA0775 SETTING CLASSIFICATION: Concrete bridge guardrail OPUS PID: LATITUDE: 24° 37.4' N ( 24.62330) LONGITUDE: 81° 36.1' W ( -81.60170) The bench mark is a disk set on a concrete guardrail, 7.10 m (23.3 ft) SE of the centerline of U.S. Highway 1, 3.20 m (10.5 ft) SW of the NE end of the guardrail, 1.49 m (4.9 ft) NW of the SE edge of the U.S. Highway 1 bridge cheekwall, 0.15 m (0.5 ft) NE of the NE 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 5 of 6 Station ID: 8724405 PUBLICATION DATE: 01/06/2004 Name: SADDLEBUNCH CHANNEL NO. 3 FL NOAA Chart: 11442 Latitude: 24° 37.4' N ( 24.62330) USGS Quad: SUGARLOAF KEY Longitude: 81° 36.2' W ( -81.60330) T I D A L D A T U M S Tidal datums at SADDLEBUNCH CHANNEL NO. 3 based on: LENGTH OF SERIES: 1 MONTH TIME PERIOD: February 1975 - February 1975 TIDAL EPOCH: 1983-2001 CONTROL TIDE STATION: 8724211 BIG PINE KEY VIADUCT Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in METERS: MEAN HIGHER HIGH WATER MHHW = 0.278 North American Vertical Datum NAVD88 = 0.220 MEAN HIGH WATER MHW = 0.198 MEAN TIDE LEVEL MTL = 0.106 MEAN SEA LEVEL MSL = 0.087 MEAN LOW WATER MLW = 0.014 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 1 1975 2.328 2.130 NO 2 1975 2.320 2.122 NO 3 1975 0.927 0.729 NO 4 1975 0.967 0.769 NO 5 1975 0.907 0.709 4405 F 4.767 4.569
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 6 of 6 Station ID: 8724405 PUBLICATION DATE: 01/06/2004 Name: SADDLEBUNCH CHANNEL NO. 3 FL NOAA Chart: 11442 Latitude: 24° 37.4' N ( 24.62330) USGS Quad: SUGARLOAF KEY Longitude: 81° 36.2' W ( -81.60330) 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.