U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Datums Page Page 1 of 6 Station ID: 8731439 PUBLICATION DATE: 08/19/2010 Name: GULF SHORES, ICWW AL NOAA Chart: 11376 Latitude: 30° 16.8' N ( 30.27989) USGS Quad: GULF SHORES Longitude: 87° 41.1' W ( -87.68428) To reach the station from Hwy 98 and Hwy 59 in Foley, Al turn left on 59 and proceed 6.2 miles to the bridge over the ICW and the light. Before going over the bridge at the light and E 29th St turn left on 29th and then right on 1st Ave and head towards LuLu's restaurant and the station is at the corner of the fuel docks. The bench marks are located in the vicinity of the tide station. T I D A L B E N C H M A R K S PRIMARY BENCH MARK STAMPING: 1439 A 2008 DESIGNATION: 873 1439 A MONUMENTATION: Tidal Station disk VM#: 18961 AGENCY: National Ocean Survey/Service(NOS) IDB PID#: SETTING CLASSIFICATION: Concrete cap OPUS PID: LATITUDE: 30° 16.8' N ( 30.27989) LONGITUDE: 87° 41.1' W ( -87.68431) The bench mark is a disk set flush in the concrete cap of the bulkhead located in the the SE corner of the Valvtect fuel docks near the NOAA tidal station, 35.94 m (117.9 ft) east of the west end of the concrete cap, 4.71 m (15.5 ft) north of the south corner of the bulkhead, and 0.44 m (1.4 ft) SW of the outside corner of the concrete cap.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 2 of 6 Station ID: 8731439 PUBLICATION DATE: 08/19/2010 Name: GULF SHORES, ICWW AL NOAA Chart: 11376 Latitude: 30° 16.8' N ( 30.27989) USGS Quad: GULF SHORES Longitude: 87° 41.1' W ( -87.68428) T I D A L B E N C H M A R K S BENCH MARK STAMPING: 1439 B 2008 DESIGNATION: 873 1439 B MONUMENTATION: Tidal Station disk VM#: 18962 AGENCY: National Ocean Survey/Service(NOS) IDB PID#: SETTING CLASSIFICATION: Foundation for fuel tank OPUS PID: LATITUDE: 30° 16.8' N ( 30.28003) LONGITUDE: 87° 41.1' W ( -87.68433) The bench mark is a disk set flush in the NE corner of a concrete pad for a fuel tank for the valvtect fuel dock, 26.39 m (86.6 ft) east of the east side of a white freezer, 23.61 m (77.5 ft) SW of the centerline of the entrance road to the back lot of Lulu's, 10.67 m (35.0 ft) North of the south corner of the concrete pad. BENCH MARK STAMPING: 1439 C 2008 DESIGNATION: 873 1439 C MONUMENTATION: See descriptive text VM#: 18963 AGENCY: National Ocean Survey/Service(NOS) IDB PID#: SETTING CLASSIFICATION: Concrete floor OPUS PID: LATITUDE: 30° 16.8' N ( 30.28006) LONGITUDE: 87° 41.1' W ( -87.68494) The bench mark is a disk set flush in concrete floor located inside the restaurant near the double entrance doors, SE of the hostess counter, 6.06 m (19.9 ft) WSW of the men's room door, 2.58 m (8.5 ft) SSW of the double entrance doors, and 0.64 m (2.1 ft) NE of a wall.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 3 of 6 Station ID: 8731439 PUBLICATION DATE: 08/19/2010 Name: GULF SHORES, ICWW AL NOAA Chart: 11376 Latitude: 30° 16.8' N ( 30.27989) USGS Quad: GULF SHORES Longitude: 87° 41.1' W ( -87.68428) T I D A L B E N C H M A R K S BENCH MARK STAMPING: 1439 D 2008 DESIGNATION: 873 1439 D MONUMENTATION: Tidal Station disk VM#: 18964 AGENCY: National Ocean Survey/Service(NOS) IDB PID#: SETTING CLASSIFICATION: Concrete cap OPUS PID: LATITUDE: 30° 16.8' N ( 30.28072) LONGITUDE: 87° 41.1' W ( -87.68539) The bench mark is a disk set flush in the concrete on bulkhead cap on the SE side of the marina, north of the volley vall courts, 21.64 m (71.0 ft) NW of the NW corner of the laundry building, 16.47 m (54.0 ft) NE of the SW corner of the bulkhead, 3.89 m (12.8 ft) north of a 1.38 m (4.53 ft) high concrete block wall around the volleyball court and 0.33 m (1.1 ft) SE of the face of the concrete cap. BENCH MARK STAMPING: 1439 E 2008 DESIGNATION: 873 1439 E MONUMENTATION: Tidal Station disk VM#: 18965 AGENCY: National Ocean Survey/Service(NOS) IDB PID#: SETTING CLASSIFICATION: Concrete cap OPUS PID: LATITUDE: 30° 16.8' N ( 30.28072) LONGITUDE: 87° 41.1' W ( -87.68492) The mark is a disk set flush inside the SE corner of the bulkhead in a concrete cap, 14.77 m (48.5 ft) east of the east corner of the bathroom building, 3.31 m (10.9 ft) SW of the centerline of a gangway ramp to the southernmost floating dock, and 2.10 m (6.9 ft) NW of the SE concrete block retaining wall.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 4 of 6 Station ID: 8731439 PUBLICATION DATE: 08/19/2010 Name: GULF SHORES, ICWW AL NOAA Chart: 11376 Latitude: 30° 16.8' N ( 30.27989) USGS Quad: GULF SHORES Longitude: 87° 41.1' W ( -87.68428) T I D A L B E N C H M A R K S BENCH MARK STAMPING: 1439 F 2010 DESIGNATION: 873 1439 F MONUMENTATION: Survey disk VM#: 19666 AGENCY: National Ocean Survey/service (NOS) IDB PID#: SETTING CLASSIFICATION: Concrete cap OPUS PID#: BBBV39 LATITUDE: 30° 16.9' N ( 30.28207) LONGITUDE: 87° 41.1' W ( -87.68492) The bench mark is a disk set flush in the concrete cap at the north end of Homeport Marina 32.65 m (107.1 ft) west of the center of the gang way ramp leading to floating dock 'C', 21.18 m (69.5 ft) east of the center of the gangway ramp leading to floating dock 'B', and 2.59 m (8.5 ft) south of concrete block retaining wall.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 5 of 6 Station ID: 8731439 PUBLICATION DATE: 08/19/2010 Name: GULF SHORES, ICWW AL NOAA Chart: 11376 Latitude: 30° 16.8' N ( 30.27989) USGS Quad: GULF SHORES Longitude: 87° 41.1' W ( -87.68428) T I D A L D A T U M S Tidal datums at GULF SHORES, ICWW based on: LENGTH OF SERIES: 1 YEAR TIME PERIOD: March 2009 - February 2010 TIDAL EPOCH: 1983-2001 CONTROL TIDE STATION: 8735180 DAUPHIN ISLAND, MOBILE BAY Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in METERS: HIGHEST OBSERVED WATER LEVEL (11/10/2009) = 1.248 MEAN HIGHER HIGH WATER MHHW = 0.371 MEAN HIGH WATER MHW = 0.356 MEAN TIDE LEVEL MTL = 0.190 MEAN SEA LEVEL MSL = 0.182 MEAN LOW WATER MLW = 0.023 MEAN LOWER LOW WATER MLLW = 0.000 LOWEST OBSERVED WATER LEVEL (02/05/2009) = -0.467 North American Vertical Datum (NAVD88) Bench Mark Elevation Information In METERS above: Stamping or Designation MLLW MHW 1439 A 2008 1.394 1.038 1439 B 2008 3.194 2.838 1439 C 2008 3.235 2.879 1439 D 2008 1.716 1.360 1439 E 2008 1.705 1.349 1439 F 2010 1.696 1.340 Foot Notes: Bench mark 1439 F 2010 is based on one differential leveling connection and does not meet the quality control standards of the NOS. Therefore, caution should be used when deriving elevations for this mark.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 6 of 6 Station ID: 8731439 PUBLICATION DATE: 08/19/2010 Name: GULF SHORES, ICWW AL NOAA Chart: 11376 Latitude: 30° 16.8' N ( 30.27989) USGS Quad: GULF SHORES Longitude: 87° 41.1' W ( -87.68428) 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.