U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Datums Page Page 1 of 6 Station ID: 8723852 PUBLICATION DATE: 04/01/2004 Name: LOWER MATECUMBE KEY, FLA. BAY FL NOAA Chart: 11452 Latitude: 24° 51.9' N ( 24.86500) USGS Quad: LOWER MATECUMBE KEY Longitude: 80° 43.0' W ( -80.71670) To reach the tidal bench marks proceed 11.7 km (7.3 mi) SW from the post office in Islamorada on U.S. Highway 1, thence 0.2 km (0.1 mi) north along a private driveway to the Game Fish Resort Motel. The bench marks are in the vicinity of the motel along the seawall and a hurricane fence north of the motel. The tide gage and staff were located on a small dock near the boat ramp SW of the motel. T I D A L B E N C H M A R K S PRIMARY BENCH MARK STAMPING: F 328 1970 DESIGNATION: F 328 MONUMENTATION: Bench Mark disk VM#: 10932 AGENCY: National Geodetic Survey (NGS) IDB PID#: AA0405 SETTING CLASSIFICATION: Rock outcrop OPUS PID: LATITUDE: 24° 51.9' N ( 24.86500) LONGITUDE: 80° 43.0' W ( -80.71670) The primary bench mark is a disk set in top of a rock ledge at the water's edge, 22.04 m (72.3 ft) NW of the NW corner of the most northerly motel unit, 7.10 m (23.3 ft) NW of bench mark E 328 1970, 4.11 m (13.5 ft) SE of the NW end of a hurricane fence along the side of the motel property, 2.90 m (9.5 ft) south of a fence, 0.30 m (1.0 ft) west of the west edge of a sea wall, and 0.30 m (1.0 ft) below the sea wall.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 2 of 6 Station ID: 8723852 PUBLICATION DATE: 04/01/2004 Name: LOWER MATECUMBE KEY, FLA. BAY FL NOAA Chart: 11452 Latitude: 24° 51.9' N ( 24.86500) USGS Quad: LOWER MATECUMBE KEY Longitude: 80° 43.0' W ( -80.71670) T I D A L B E N C H M A R K S BENCH MARK STAMPING: B 328 1970 DESIGNATION: B 328 MONUMENTATION: Bench Mark disk VM#: 10928 AGENCY: National Geodetic Survey (NGS) IDB PID#: AA0402 SETTING CLASSIFICATION: Rock outcrop OPUS PID: LATITUDE: 24° 51.9' N ( 24.86500) LONGITUDE: 80° 43.0' W ( -80.71670) The bench mark is a disk set in top of the rock ledge at the water's edge, 23.26 m (76.3 ft) west of the SW corner of the most northerly unit of the Game Fish Resort Motel, 6.80 m (22.3 ft) south of the south edge of a concrete boat ramp, 0.12 m (0.4 ft) west of the west face of the sea wall, and 0.61 m (2.0 ft) below the top of the sea wall.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 3 of 6 Station ID: 8723852 PUBLICATION DATE: 04/01/2004 Name: LOWER MATECUMBE KEY, FLA. BAY FL NOAA Chart: 11452 Latitude: 24° 51.9' N ( 24.86500) USGS Quad: LOWER MATECUMBE KEY Longitude: 80° 43.0' W ( -80.71670) T I D A L B E N C H M A R K S BENCH MARK STAMPING: D 328 1970 DESIGNATION: D 328 MONUMENTATION: Bench Mark disk VM#: 10930 AGENCY: National Geodetic Survey (NGS) IDB PID#: AA0403 SETTING CLASSIFICATION: Bedrock OPUS PID: LATITUDE: 24° 51.8' N ( 24.86330) LONGITUDE: 80° 43.0' W ( -80.71670) The bench mark is a disk set in top of a bedrock outcrop 10 m (34 ft) east of a sea wall, 10.15 m (33.3 ft) SE of bench mark E 328 1970, 5 m (17 ft) NW of the NW corner of a metal unit, 3 m (9 ft) south of a hurricane fence, and level with the ground.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 4 of 6 Station ID: 8723852 PUBLICATION DATE: 04/01/2004 Name: LOWER MATECUMBE KEY, FLA. BAY FL NOAA Chart: 11452 Latitude: 24° 51.9' N ( 24.86500) USGS Quad: LOWER MATECUMBE KEY Longitude: 80° 43.0' W ( -80.71670) T I D A L B E N C H M A R K S BENCH MARK STAMPING: E 328 1970 DESIGNATION: E 328 MONUMENTATION: Bench Mark disk VM#: 10931 AGENCY: National Geodetic Survey (NGS) IDB PID#: AA0400 SETTING CLASSIFICATION: Bedrock OPUS PID: LATITUDE: 24° 51.9' N ( 24.86500) LONGITUDE: 80° 43.0' W ( -80.71670) The bench mark is a disk set in top of a bedrock outcrop 23 m (75 ft) north of the north edge of a boat ramp, 15.30 m (50.2 ft) NW of the NW corner of the most northerly motel unit, 11 m (36 ft) SE of the NW end of a hurricane fence around the motel property, 10.15 m (33.3 ft) NW of bench mark D 328 1970, 7.10 m (23.3 ft) SE of bench mark F 328 1970, 4 m (14 ft) south of the fence, 2.87 m (9.4 ft) east of the east face of a sea wall, and level with the ground. BENCH MARK STAMPING: 3852 F 1982 DESIGNATION: 872 3852 F TIDAL ALIAS: MONUMENTATION: Tidal Station disk VM#: 10933 AGENCY: National Ocean Survey (NOS) IDB PID#: AA0804 SETTING CLASSIFICATION: Concrete bulkhead OPUS PID: LATITUDE: 24° 51.9' N ( 24.86500) LONGITUDE: 80° 43.0' W ( -80.71670) The bench mark is a disk set in a concrete bulkhead 16 m (53 ft) WSW of the NW corner of the motel, 7.74 m (25.4 ft) NNE of the east corner of a pavilion, 1.83 m (6.0 ft) SW of the center of a boat ramp, and about level with the ground. BENCH MARK STAMPING: 3852 G 1982 DESIGNATION: 872 3852 G TIDAL ALIAS: MONUMENTATION: Tidal Station disk VM#: 10934 AGENCY: National Ocean Survey (NOS) IDB PID#: AA0803 SETTING CLASSIFICATION: Concrete base for sign OPUS PID: LATITUDE: 24° 51.9' N ( 24.86500) LONGITUDE: 80° 43.0' W ( -80.71670) The bench mark is a disk set in the concrete base of the sign for the Game Fish Resort motel, 32.10 m (105.3 ft) NW of the centerline of U.S. Highway 1, 25.45 m (83.5 ft) NE of the concrete power pole No. 889, 13.72 m (45.0 ft) SW of the centerline of the road to the motel, 0.12 m (0.4 ft) SE of the SE steel support for the Game Fish Resort motel sign, and 0.61 m (2.0 ft) below the level of the highway.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 5 of 6 Station ID: 8723852 PUBLICATION DATE: 04/01/2004 Name: LOWER MATECUMBE KEY, FLA. BAY FL NOAA Chart: 11452 Latitude: 24° 51.9' N ( 24.86500) USGS Quad: LOWER MATECUMBE KEY Longitude: 80° 43.0' W ( -80.71670) T I D A L D A T U M S Tidal datums at LOWER MATECUMBE KEY, FLA. BAY based on: LENGTH OF SERIES: 1 YEAR TIME PERIOD: January 1971 - December 1971 TIDAL EPOCH: 1983-2001 CONTROL TIDE STATION: 8724580 KEY WEST Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in METERS: HIGHEST OBSERVED WATER LEVEL (03/30/1971) = 0.479 North American Vertical Datum NAVD88 = 0.396 MEAN HIGHER HIGH WATER MHHW = 0.299 MEAN HIGH WATER MHW = 0.257 MEAN TIDE LEVEL MTL = 0.142 MEAN SEA LEVEL MSL = 0.139 MEAN LOW WATER MLW = 0.027 MEAN LOWER LOW WATER MLLW = 0.000 LOWEST OBSERVED WATER LEVEL (02/10/1971) = -0.389 North American Vertical Datum (NAVD88) Bench Mark Elevation Information In METERS above: Stamping or Designation MLLW MHW F 328 1970 0.440 0.183 B 328 1970 0.326 0.069 D 328 1970 0.589 0.332 E 328 1970 0.557 0.300 3852 F 1982 0.690 0.433 3852 G 1982 1.123 0.866
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 6 of 6 Station ID: 8723852 PUBLICATION DATE: 04/01/2004 Name: LOWER MATECUMBE KEY, FLA. BAY FL NOAA Chart: 11452 Latitude: 24° 51.9' N ( 24.86500) USGS Quad: LOWER MATECUMBE KEY Longitude: 80° 43.0' W ( -80.71670) 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.