U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Datums Page Page 1 of 5 Station ID: 8727151 PUBLICATION DATE: 12/12/2003 Name: BAYPORT FL NOAA Chart: 11409 Latitude: 28° 32.0' N ( 28.53330) USGS Quad: BAYPORT Longitude: 82° 39.0' W ( -82.65000) To reach the tidal bench marks from the intersection of U.S. Highway 19 and State Road 50 in Weeki Wachee Springs, proceed west on State Road 50 for 10.0 km (6.2 mi) to its end at the County Park at Bayport. The bench marks are located in area around the park. The tide gage and staff were located on the park fishing pier. T I D A L B E N C H M A R K S PRIMARY BENCH MARK STAMPING: 7151 D 1978 DESIGNATION: 872 7151 D TIDAL MONUMENTATION: Tidal Station disk VM#: 7743 AGENCY: National Ocean Survey (NOS) IDB PID#: AL7725 SETTING CLASSIFICATION: Stainless steel rod OPUS PID: LATITUDE: 28° 32.1' N ( 28.53500) LONGITUDE: 82° 39.0' W ( -82.65000) The primary bench mark is a disk located 11.70 m (38.4 ft) west of the the centerline of the road, 2.01 m (6.6 ft) east of a concrete retaining wall, and 1.01 m (3.3 ft) north of a witness post. The bench mark is crimped to the top of a stainless steel rod driven 3.4 m (11 ft) to refusal and encased in PVC pipe and a concrete kickblock.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 2 of 5 Station ID: 8727151 PUBLICATION DATE: 12/12/2003 Name: BAYPORT FL NOAA Chart: 11409 Latitude: 28° 32.0' N ( 28.53330) USGS Quad: BAYPORT Longitude: 82° 39.0' W ( -82.65000) T I D A L B E N C H M A R K S BENCH MARK STAMPING: 7151 A 1978 DESIGNATION: 872 7151 A TIDAL MONUMENTATION: Tidal Station disk VM#: 7740 AGENCY: National Ocean Survey (NOS) IDB PID#: AL7724 SETTING CLASSIFICATION: Concrete monument OPUS PID: LATITUDE: 28° 32.2' N ( 28.53670) LONGITUDE: 82° 39.0' W ( -82.65000) The bench mark is a disk set in the top of a concrete monument located 30.48 m (100.0 ft) north of a concrete bulkhead along a canal, 16.89 m (55.4 ft) west of the SW corner of a covered picnic shelter, 4.57 m (15.0 ft) east of the centerline of the paved entrance road, 2.13 m (7.0 ft) NE of the SW corner of the curbing around the picnic area, 1.68 m (5.5 ft) SW of the westernmost palm tree in the picnic area, and 0.03 m (0.1 ft) below ground level. BENCH MARK STAMPING: 7151 B 1978 DESIGNATION: 872 7151 B TIDAL MONUMENTATION: Tidal Station disk VM#: 7741 AGENCY: National Ocean Survey (NOS) IDB PID#: AL7722 SETTING CLASSIFICATION: Concrete monument OPUS PID: LATITUDE: 28° 32.2' N ( 28.53670) LONGITUDE: 82° 39.0' W ( -82.65000) The bench mark is a disk set in top of a concrete monument located in a triangular grass median strip on the south side of the park entrance road, 98 m (323 ft) NE of bench mark 7151 A 1978, 22.68 m (74.4 ft) NNE of the NE corner of the restroom building, 4.97 m (16.3 ft) south of the centerline of the entrance road, 4.21 m (13.8 ft) west of a palm tree, 2.99 m (9.8 ft) east of a 0.61 m (2.0 ft) pine tree, 0.15 m (1.5 ft) south of a witness post, and 0.03 m (0.1 ft) below ground level.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 3 of 5 Station ID: 8727151 PUBLICATION DATE: 12/12/2003 Name: BAYPORT FL NOAA Chart: 11409 Latitude: 28° 32.0' N ( 28.53330) USGS Quad: BAYPORT Longitude: 82° 39.0' W ( -82.65000) T I D A L B E N C H M A R K S BENCH MARK STAMPING: 7151 C 1978 DESIGNATION: 872 7151 C TIDAL MONUMENTATION: Tidal Station disk VM#: 7742 AGENCY: National Ocean Survey (NOS) IDB PID#: AL7723 SETTING CLASSIFICATION: Concrete monument OPUS PID: LATITUDE: 28° 32.2' N ( 28.53670) LONGITUDE: 82° 39.0' W ( -82.65000) The bench mark is a disk set in top of a concrete monument located 55.02 m (180.5 ft) SSW of bench mark 7151 B 1978, 41.03 m (134.6 ft) east of the SE corner of the westernmost of two boat ramps, 26.55 m (87.1 ft) south of the SE corner of the restroom buildings, 4.57 m (15.0 ft) west of the west edge of the easternmost boat ramp, 2.68 m (8.8 ft) north of a concrete bulkhead for the canal, and 0.06 m (0.2 ft) below ground level. BENCH MARK STAMPING: 50 ERS TT 1952 3.9 DESIGNATION: 50 ERS TT MONUMENTATION: Survey disk VM#: 7744 AGENCY: U.S. Geological Survey (USGS) IDB PID#: AL7726 SETTING CLASSIFICATION: Concrete bulkhead OPUS PID: LATITUDE: 28° 32.0' N ( 28.53330) LONGITUDE: 82° 39.0' W ( -82.65000) The bench mark is a disk set in the concrete bulkhead located at the west end of the paved parking area at the end of the road, 7.74 m (25.4 ft) south of the parking area, 5.79 m (19.0 ft) west of the NW end of the fishing pier, and 0.43 m (1.4 ft) north of the south edge of the concrete bulkhead.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 4 of 5 Station ID: 8727151 PUBLICATION DATE: 12/12/2003 Name: BAYPORT FL NOAA Chart: 11409 Latitude: 28° 32.0' N ( 28.53330) USGS Quad: BAYPORT Longitude: 82° 39.0' W ( -82.65000) T I D A L D A T U M S Tidal datums at BAYPORT based on: LENGTH OF SERIES: 4 MONTHS TIME PERIOD: December 1978 - March 1979 TIDAL EPOCH: 1983-2001 CONTROL TIDE STATION: 8726724 CLEARWATER BEACH, GULF OF MEXICO Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in METERS: MEAN HIGHER HIGH WATER MHHW = 0.963 MEAN HIGH WATER MHW = 0.846 North American Vertical Datum NAVD88 = 0.561 MEAN TIDE LEVEL MTL = 0.492 MEAN SEA LEVEL MSL = 0.480 MEAN LOW WATER MLW = 0.137 MEAN LOWER LOW WATER MLLW = 0.000 North American Vertical Datum (NAVD88) Bench Mark Elevation Information In METERS above: Stamping or Designation MLLW MHW 7151 D 1978 1.569 0.723 7151 A 1978 2.100 1.254 7151 B 1978 2.061 1.215 7151 C 1978 1.604 0.758 50 ERS TT 1952 3.9 1.479 0.633
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 5 of 5 Station ID: 8727151 PUBLICATION DATE: 12/12/2003 Name: BAYPORT FL NOAA Chart: 11409 Latitude: 28° 32.0' N ( 28.53330) USGS Quad: BAYPORT Longitude: 82° 39.0' W ( -82.65000) 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.