U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Datums Page Page 1 of 7 Station ID: 8724489 PUBLICATION DATE: 02/05/2004 Name: BIG COPPITT KEY FL NOAA Chart: 11445 Latitude: 24° 36.1' N ( 24.60170) USGS Quad: BOCA CHICA KEY Longitude: 81° 39.3' W ( -81.65500) To reach the tidal bench marks from the Catholic Church in Key West, proceed NE on U.S. Highway 1 for 15.9 km (9.9 mi) to Diamond Road, then turn left and proceed north on Diamond Road for 0.3 km (0.2 mi) to the end of the road. The bench marks are located along Diamond Road. The tide gage and staff were located off the north end of Diamond Road. T I D A L B E N C H M A R K S PRIMARY BENCH MARK STAMPING: NO 4 1974 DESIGNATION: 872 4489 TIDAL 4 MONUMENTATION: Tidal Station disk VM#: 11038 AGENCY: National Ocean Survey (NOS) IDB PID#: AA0989 SETTING CLASSIFICATION: Concrete monument OPUS PID: LATITUDE: 24° 36.2' N ( 24.60330) LONGITUDE: 81° 39.3' W ( -81.65500) The primary bench mark is a disk set in a concrete post near the NW property corner at 7 Diamond Road, 9 m (31 ft) east of the centerline of the road, and 0.06 m (0.2 ft) above the ground.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 2 of 7 Station ID: 8724489 PUBLICATION DATE: 02/05/2004 Name: BIG COPPITT KEY FL NOAA Chart: 11445 Latitude: 24° 36.1' N ( 24.60170) USGS Quad: BOCA CHICA KEY Longitude: 81° 39.3' W ( -81.65500) T I D A L B E N C H M A R K S BENCH MARK STAMPING: U 70 RESET 1939 DESIGNATION: U 70 RESET MONUMENTATION: Bench Mark disk VM#: 11033 AGENCY: US Coast and Geodetic Survey (USC&GS) IDB PID#: AA0109 SETTING CLASSIFICATION: Concrete wing wall OPUS PID: LATITUDE: 24° 35.6' N ( 24.59330) LONGITUDE: 81° 39.9' W ( -81.66500) The bench mark is a disk set in the top of the SE concrete wing wall at the NE end of the Rockland Channel Viaduct, 5.03 m (16.5 ft) SE of the centerline of U.S. Highway 1, and 0.76 m (2.5 ft) below highway level. BENCH MARK STAMPING: 4489 F 1982 DESIGNATION: 872 4489 F TIDAL MONUMENTATION: Tidal Station disk VM#: 11034 AGENCY: National Ocean Survey (NOS) IDB PID#: AA0993 SETTING CLASSIFICATION: Concrete and limerock pillar OPUS PID: LATITUDE: 24° 35.9' N ( 24.59830) LONGITUDE: 81° 39.2' W ( -81.65330) The bench mark is a disk set vertically in the west side of a 1 m (3 ft) square and 2.44 m (8.0 ft) high concrete and limerock pillar at the junction of U.S. Highway 1 and Diamond Road, 26.64 m (87.4 ft) ESE of the SE fence corner at Southern Furniture Sales, 21.92 m (71.9 ft) NW of the centerline of U.S. Highway 1, 7.41 m (24.3 ft) east of the centerline of Diamond Road, 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: 8724489 PUBLICATION DATE: 02/05/2004 Name: BIG COPPITT KEY FL NOAA Chart: 11445 Latitude: 24° 36.1' N ( 24.60170) USGS Quad: BOCA CHICA KEY Longitude: 81° 39.3' W ( -81.65500) T I D A L B E N C H M A R K S BENCH MARK STAMPING: NO 1 1974 DESIGNATION: 872 4489 TIDAL 1 MONUMENTATION: Tidal Station disk VM#: 11035 AGENCY: National Ocean Survey (NOS) IDB PID#: AA0990 SETTING CLASSIFICATION: Concrete monument OPUS PID: LATITUDE: 24° 36.1' N ( 24.60170) LONGITUDE: 81° 39.3' W ( -81.65500) The bench mark is a disk set in a concrete post located near the north end of Diamond Road on the extended centerline, 6 m (19 ft) north of a power pole and 2 m (5 ft) north of a guide wire. BENCH MARK STAMPING: NO 2 1974 DESIGNATION: 872 4489 TIDAL 2 MONUMENTATION: Tidal Station disk VM#: 11036 AGENCY: National Ocean Survey (NOS) IDB PID#: AA0991 SETTING CLASSIFICATION: Concrete monument OPUS PID: LATITUDE: 24° 36.1' N ( 24.60170) LONGITUDE: 81° 39.3' W ( -81.65500) The bench mark is a disk set in a concrete post near the north end of Diamond Road on the exteded centerline, 1 m (4 ft) south of a power pole.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 4 of 7 Station ID: 8724489 PUBLICATION DATE: 02/05/2004 Name: BIG COPPITT KEY FL NOAA Chart: 11445 Latitude: 24° 36.1' N ( 24.60170) USGS Quad: BOCA CHICA KEY Longitude: 81° 39.3' W ( -81.65500) T I D A L B E N C H M A R K S BENCH MARK STAMPING: NO 5 1974 DESIGNATION: 872 4489 TIDAL 5 MONUMENTATION: Tidal Station disk VM#: 11039 AGENCY: National Ocean Survey (NOS) IDB PID#: AA1636 SETTING CLASSIFICATION: Concrete monument OPUS PID: LATITUDE: 24° 36.2' N ( 24.60330) LONGITUDE: 81° 39.3' W ( -81.65500) The bench mark is a disk set along Diamond Road, about halfway between U.S. Highway 1 and the end of Diamond Road, 6 m (20 ft) west of the Diamond Road centerline, and 1 m (2 ft) north of power pole #BC 21-150. BENCH MARK STAMPING: 4489 G 1986 DESIGNATION: 872 4489 G TIDAL MONUMENTATION: Tidal Station disk VM#: 11310 AGENCY: National Ocean Service (NOS) IDB PID#: AA1637 SETTING CLASSIFICATION: Concrete base for a metal power pole OPUS PID: LATITUDE: 24° 35.9' N ( 24.59830) LONGITUDE: 81° 39.2' W ( -81.65330) The bench mark is a disk set in the north edge of the concrete base for a metal power pole, 51.82 m (170.0 ft) WSW of the extended centerline of Aquamarine Drive, 46.33 m (152.0 ft) ESE of bench mark 4489 F 1982, 43.89 m (144.0 ft) ENE of the NE corner of a fence around an electrical transmission station, 12.41 m (40.7 ft) SSE of the centerline of U.S. Highway 1, and 1 m (3 ft) below the level of the highway.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 5 of 7 Station ID: 8724489 PUBLICATION DATE: 02/05/2004 Name: BIG COPPITT KEY FL NOAA Chart: 11445 Latitude: 24° 36.1' N ( 24.60170) USGS Quad: BOCA CHICA KEY Longitude: 81° 39.3' W ( -81.65500) T I D A L B E N C H M A R K S BENCH MARK STAMPING: 4489 H 1986 DESIGNATION: 872 4489 H TIDAL MONUMENTATION: Tidal Station disk VM#: 11311 AGENCY: National Ocean Service (NOS) IDB PID#: AA1638 SETTING CLASSIFICATION: Concrete base for a metal power pole OPUS PID: LATITUDE: 24° 35.8' N ( 24.59670) LONGITUDE: 81° 39.1' W ( -81.65170) The bench mark is a disk set in the north edge of the concrete base for a metal power pole, 0.24 km (0.15 mi) NE of bench mark 4489 F 1986, 13.11 m (43.0 ft) SSE of the centerline of U.S. Highway 1, 9.91 m (32.5 ft) ENE of the centerline of County Road 941, and 0.61 m (2.0 ft) below the level of road.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 6 of 7 Station ID: 8724489 PUBLICATION DATE: 02/05/2004 Name: BIG COPPITT KEY FL NOAA Chart: 11445 Latitude: 24° 36.1' N ( 24.60170) USGS Quad: BOCA CHICA KEY Longitude: 81° 39.3' W ( -81.65500) T I D A L D A T U M S Tidal datums at BIG COPPITT KEY 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: MEAN HIGHER HIGH WATER MHHW = 0.481 MEAN HIGH WATER MHW = 0.389 North American Vertical Datum NAVD88 = 0.354 MEAN TIDE LEVEL MTL = 0.206 MEAN SEA LEVEL MSL = 0.166 MEAN LOW WATER MLW = 0.023 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 1974 1.507 1.118 U 70 RESET 1939 2.374 1.985 4489 F 1982 2.406 2.017 NO 1 1974 1.358 0.969 NO 2 1974 1.431 1.042 NO 5 1974 1.571 1.182 4489 G 1986 1.223 0.834 4489 H 1986 2.036 1.647 Foot Notes: Bench marks U 70 RESET 1939. P 272 1966, 4489 G 1986 and 4489 H 1986 are based on one differential leveling connection and do not meet the quality control standards of the NOS. Therefore, caution should be used when deriving elevationsfor these marks.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 7 of 7 Station ID: 8724489 PUBLICATION DATE: 02/05/2004 Name: BIG COPPITT KEY FL NOAA Chart: 11445 Latitude: 24° 36.1' N ( 24.60170) USGS Quad: BOCA CHICA KEY Longitude: 81° 39.3' W ( -81.65500) 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.