U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Datums Page Page 1 of 5 Station ID: 8724992 PUBLICATION DATE: 11/13/2003 Name: ADDISON BAY FL NOAA Chart: 11429 Latitude: 25° 57.8' N ( 25.96330) USGS Quad: MARCO ISLAND Longitude: 81° 39.9' W ( -81.66500) To reach the tidal bench marks from the Moran's Barge Marina at the west end of State Road 92 bridge over Big Marco River, proceed by boat NW along the marked channel of the Big Marco River to the vicinity of marker 20, then proceed north along Angelwing Creek to Addison Bay, then proceed NE in Addison Bay to a small mangrove island, then head east to the mainland. The bench marks are located on the mainland along a cut line in the mangroves. The tide gage and staff were located between the small island and mainland on a small offshore platform. T I D A L B E N C H M A R K S PRIMARY BENCH MARK STAMPING: 4992 A 1978 DESIGNATION: 872 4992 A MONUMENTATION: Tidal Station disk VM#: 9763 AGENCY: National Ocean Service (NOS) IDB PID#: SETTING CLASSIFICATION: Galvanized steel rod OPUS PID: LATITUDE: 25° 57.8' N ( 25.96330) LONGITUDE: 81° 39.9' W ( -81.66500) The primary bench mark is a disk located 198 m (650 ft) east of a small island, 1.83 m (6.0 ft) east of the west edge of the mangroves and 0.37 m (1.2 ft) west of a witness post. The bench mark is 0.27 m (0.9 ft) above ground level, crimped to a galvanized steel rod driven 10.7 m (35 ft) to refusal, and encased in a 4-inch steel pipe.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 2 of 5 Station ID: 8724992 PUBLICATION DATE: 11/13/2003 Name: ADDISON BAY FL NOAA Chart: 11429 Latitude: 25° 57.8' N ( 25.96330) USGS Quad: MARCO ISLAND Longitude: 81° 39.9' W ( -81.66500) T I D A L B E N C H M A R K S BENCH MARK STAMPING: 4992 B 1978 DESIGNATION: 872 4992 B MONUMENTATION: Tidal Station disk VM#: 9764 AGENCY: National Ocean Service (NOS) IDB PID#: SETTING CLASSIFICATION: Galvanized steel rod OPUS PID: LATITUDE: 25° 57.8' N ( 25.96330) LONGITUDE: 81° 39.9' W ( -81.66500) The bench mark is a disk located 26.55 m (87.1 ft) north of bench mark 4992 A 1978, 7 m (23 ft) east of the west edge of the mangroves, and 0.37 m (1.2 ft) west of a witness post. The bench mark is 0.37 m (1.2 ft) above the ground level, crimped to a galvanized steel rod driven 9.8 m (32 ft) to refusal, and encased in a 4-inch steel pipe. BENCH MARK STAMPING: 4992 C 1978 DESIGNATION: 872 4992 C MONUMENTATION: Tidal Station disk VM#: 9765 AGENCY: National Ocean Service (NOS) IDB PID#: SETTING CLASSIFICATION: Galvanized steel rod OPUS PID: LATITUDE: 25° 57.8' N ( 25.96330) LONGITUDE: 81° 39.9' W ( -81.66500) The bench mark is a disk located 36.94 m (121.2 ft) east of the west edge of the mangroves, 33.95 m (111.4 ft) ESE of bench mark 4992 B 1978, 0.40 m (1.3 ft) NNW of an old witness post, and 0.30 m (1.0 ft) NNW of a new witness post. The bench mark is 0.27 m (0.9 ft) above ground level, crimped to a galvanized steel rod driven 11.6 m (38 ft) to refusal, and encased in a 4-inch steel pipe.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 3 of 5 Station ID: 8724992 PUBLICATION DATE: 11/13/2003 Name: ADDISON BAY FL NOAA Chart: 11429 Latitude: 25° 57.8' N ( 25.96330) USGS Quad: MARCO ISLAND Longitude: 81° 39.9' W ( -81.66500) T I D A L B E N C H M A R K S BENCH MARK STAMPING: 4992 D 1978 DESIGNATION: 872 4992 D MONUMENTATION: Tidal Station disk VM#: 9766 AGENCY: National Ocean Service (NOS) IDB PID#: SETTING CLASSIFICATION: Galvanized steel rod OPUS PID: LATITUDE: 25° 57.8' N ( 25.96330) LONGITUDE: 81° 39.9' W ( -81.66500) The bench mark is a disk located 46.48 m (152.5 ft) east of the west edge of the mangroves, 18.62 m (61.1 ft) NE of bench mark 4992 C 1978, and 0.27 m (0.9 ft) SW of a witness post. The bench mark is 0.27 m (0.9 ft) above ground level, crimped to a galvanized steel rod driven 10.4 m (34 ft) to refusal, and encased in a 4-inch steel pipe. BENCH MARK STAMPING: 4992 E 1978 DESIGNATION: 872 4992 E MONUMENTATION: Tidal Station disk VM#: 9767 AGENCY: National Ocean Service (NOS) IDB PID#: SETTING CLASSIFICATION: Galvanized steel rod OPUS PID: LATITUDE: 25° 57.8' N ( 25.96330) LONGITUDE: 81° 39.9' W ( -81.66500) The bench mark is a disk located 57.76 m (189.5 ft) east of the west edge of the mangroves, 14.39 m (47.2 ft) NNE of Bench Mark 4992 D 1978, 9 m (30 ft) SW of the SE end of a small creek, and 0.55 m (1.8 ft) SW of a witness post. The bench mark is 0.40 m (1.3 ft) above ground level, crimped to a galvanized steel rod driven 9.8 m (32 ft) to refusal, and encased in a 4-inch steel pipe.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 4 of 5 Station ID: 8724992 PUBLICATION DATE: 11/13/2003 Name: ADDISON BAY FL NOAA Chart: 11429 Latitude: 25° 57.8' N ( 25.96330) USGS Quad: MARCO ISLAND Longitude: 81° 39.9' W ( -81.66500) T I D A L D A T U M S Tidal datums at ADDISON BAY based on: LENGTH OF SERIES: 4 MONTHS TIME PERIOD: July 1978 - October 1978 TIDAL EPOCH: 1983-2001 CONTROL TIDE STATION: 8724967 MARCO ISLAND, CAXAMBAS PASS Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in METERS: MEAN HIGHER HIGH WATER MHHW = 0.884 MEAN HIGH WATER MHW = 0.815 MEAN SEA LEVEL MSL = 0.500 MEAN TIDE LEVEL MTL = 0.487 MEAN LOW WATER MLW = 0.159 MEAN LOWER LOW WATER MLLW = 0.000 North American Vertical Datum (NAVD88) Bench Mark Elevation Information In METERS above: Stamping or Designation MLLW MHW 4992 A 1978 0.860 0.045 4992 B 1978 0.999 0.184 4992 C 1978 0.959 0.144 4992 D 1978 1.014 0.199 4992 E 1978 1.084 0.269
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 5 of 5 Station ID: 8724992 PUBLICATION DATE: 11/13/2003 Name: ADDISON BAY FL NOAA Chart: 11429 Latitude: 25° 57.8' N ( 25.96330) USGS Quad: MARCO ISLAND Longitude: 81° 39.9' W ( -81.66500) 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.