U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Datums Page Page 1 of 6 PUBLICATION DATE: 08/20/1991 Station ID: 8747437 SUPERCEDED DATE: 04/21/2003 Name: BAY WAVELAND YACHT CLUB, ST. LOUIS BAY MISSISSIPPI NOAA Chart: 11371 Latitude: 30° 19.5' N USGS Quad: BAY ST. LOUIS Longitude: 89° 19.5' W To reach the tidal bench marks from the intersection of U.S. Highway 90 and North Beach Boulevard at the west end of the U.S. Highway 90 bridge over St. Louis Bay, proceed 0.4 mile (0.6 km) north on North Beach Boulevard to Bay Waveland Yacht Club. The bench marks are in the vicinity of the yacht club and near U.S. Highway 90. The tide gage and staff are at the inside corner of the L-shaped pier on St. Louis Bay. T I D A L B E N C H M A R K S PRIMARY BENCH MARK STAMPING: 7437 A 1978 MONUMENTATION: Survey Disk VM#: 797 AGENCY: PID: SETTING CLASSIFICATION: Stainless Steel Rod The primary bench mark is next to a creosote pile supporting the club house porch at the foot of the pier, on the NE edge of a concrete patio beneath a second story deck, 47.5 feet (14.5 m) NW of the NW corner of the concrete slab of the flag pole in front of the club house, and 13.9 feet (4.2 m) east of the NE corner of the second story of the club house. The bench mark is 0.5 foot (0.2 m) below ground level, crimped to the top of a stainless steel rod driven to an unspecified depth, and encased in a 4-inch PVC pipe and concrete kickblock. BENCH MARK STAMPING: NO 1 1968 MONUMENTATION: Survey Disk VM#: 798 AGENCY: PID#: BH0937 SETTING CLASSIFICATION: Concrete Sea Wall The bench mark is set in a concrete sea wall at the entrance of Bay Waveland Yacht Club, 39 feet (12 m) NW of the center of the entrance to the yacht club, 28 feet (9 m) NW of the NW steel gate post at the entrance to the yacht club, and 18 feet (5 m) NE of the centerline of North Beach Boulevard.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 2 of 6 PUBLICATION DATE: 08/20/1991 Station ID: 8747437 SUPERCEDED DATE: 04/21/2003 Name: BAY WAVELAND YACHT CLUB, ST. LOUIS BAY MISSISSIPPI NOAA Chart: 11371 Latitude: 30° 19.5' N USGS Quad: BAY ST. LOUIS Longitude: 89° 19.5' W T I D A L B E N C H M A R K S BENCH MARK STAMPING: NO 2 1968 MONUMENTATION: Survey Disk VM#: 799 AGENCY: PID#: BH0936 SETTING CLASSIFICATION: Concrete Sea Wall The bench mark is set in the south end of a concrete sea wall, 0.4 mile (0.6 km) north of U.S. Highway 90 on North Beach Boulevard, 327 feet (100 m) SE of the center of the entrance to the yacht club, 18 feet (5 m) NE of the centerline of North Beach Boulevard, and 3.2 feet (1.0 m) NW of the SE end of the sea wall. BENCH MARK STAMPING: 7437 C 1978 MONUMENTATION: Survey Disk VM#: 802 AGENCY: PID: SETTING CLASSIFICATION: Stainless Steel Rod The bench mark is next to a utility pole in a park directly across the street from the yacht club, 51.5 feet (15.7 m) west of an old sea wall corner on the north side of the gate to the yacht club, and 25.0 feet (7.6 m) SW of the centerline of North Beach Boulevard. The bench mark is 0.8 foot (0.2 m) below ground level, crimped to the top of a stainless steel rod driven to an unspecified depth, and encased in a 4-inch PVC pipe and concrete kickblock.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 3 of 6 PUBLICATION DATE: 08/20/1991 Station ID: 8747437 SUPERCEDED DATE: 04/21/2003 Name: BAY WAVELAND YACHT CLUB, ST. LOUIS BAY MISSISSIPPI NOAA Chart: 11371 Latitude: 30° 19.5' N USGS Quad: BAY ST. LOUIS Longitude: 89° 19.5' W T I D A L B E N C H M A R K S BENCH MARK STAMPING: WEST 1954 MONUMENTATION: Survey Disk VM#: 1805 AGENCY: PID#: BH0934 SETTING CLASSIFICATION: Concrete Bridge Sidewalk The bench mark is set in the top of the north concrete sidewalk of the US highway 90 bridge over St. Louis Bay, about 405 feet (123 m) east of the west end of the bridge, 13 feet (4 m) north of the centerline of the northbound lanes of the bridge, 6.0 feet (1.8 m) east of the third light pole from the west end of the bridge, 1.0 foot (0.3 m) north of the south edge of the sidewalk, and about 0.5 foot (0.2 m) above the level of the bridge floor. BENCH MARK STAMPING: Z 214 1963 MONUMENTATION: Survey Disk VM#: 1806 AGENCY: PID#: BH0935 SETTING CLASSIFICATION: Copper-clad Steel Rod The bench mark is 316.5 feet (96.5 m) NW of the west end of the north concrete bannister of the US highway 90 bridge over St. Louis Bay, 103 feet (31 m) east of the centerline of North Beach Boulevard, 80.5 feet (24.5 m) north of the centerline of the westbound lane of the highway, 3 feet (1 m) west of powerline pole #74 and 2 feet (1 m) east of a metal witness post. The bench mark is 6 feet (2 m) below the level of the highway, crimped to a copper-clad steel rod driven 76 feet (23 m) to refusal, and encased in a 4-inch tile level with the ground.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 4 of 6 PUBLICATION DATE: 08/20/1991 Station ID: 8747437 SUPERCEDED DATE: 04/21/2003 Name: BAY WAVELAND YACHT CLUB, ST. LOUIS BAY MISSISSIPPI NOAA Chart: 11371 Latitude: 30° 19.5' N USGS Quad: BAY ST. LOUIS Longitude: 89° 19.5' W T I D A L B E N C H M A R K S BENCH MARK STAMPING: S 190 RESET 1976 MONUMENTATION: Survey Disk VM#: 12419 AGENCY: PID#: BH0941 SETTING CLASSIFICATION: Concrete Culvert The bench mark is set in the top of the east end of the south concrete headwall for a 5 foot (2 m) concrete pipe culvert with wing walls, about 0.3 mile (0.5 km) west along US Highway 90 from the west end of the bridge over St. Louis Bay, 192 feet (59 m) east of the center step at the entrance to Wayside Shrine at St. Augustine Seminary, 39.5 feet (12.0 m) south of the centerline of the eastbound lane of US Highway 90, and 2 feet (1 m) below the level of the highway.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 5 of 6 PUBLICATION DATE: 08/20/1991 Station ID: 8747437 SUPERCEDED DATE: 04/21/2003 Name: BAY WAVELAND YACHT CLUB, ST. LOUIS BAY MISSISSIPPI NOAA Chart: 11371 Latitude: 30° 19.5' N USGS Quad: BAY ST. LOUIS Longitude: 89° 19.5' W T I D A L D A T U M S Tidal datums at BAY WAVELAND YACHT CLUB, ST. LOUIS BAY based on: LENGTH OF SERIES: 11 YEARS TIME PERIOD: 1979-1989 TIDAL EPOCH: 1960-1978 CONTROL TIDE STATION: 8729840 PENSACOLA, FL Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in FEET: HIGHEST OBSERVED WATER LEVEL (08/22/1969) = 19.67 MEAN HIGHER HIGH WATER MHHW = 1.77 MEAN HIGH WATER MHW = 1.65 MEAN TIDE LEVEL MTL = 0.89 * NATIONAL GEODETIC VERTICAL DATUM NGVD29 = 0.66 MEAN LOW WATER MLW = 0.12 MEAN LOWER LOW WATER MLLW = 0.00 LOWEST OBSERVED WATER LEVEL (09/02/1985) = -3.77 * NGVD reference based on elevations published in Quad 300892, 1984, and NOS leveling of 1990. North American Vertical Datum (NAVD88) Bench Mark Elevation Information In FEET above: Stamping or Designation MLLW MHW 7437 A 1978 3.95 2.30 NO 1 1968 5.92 4.27 NO 2 1968 8.39 6.74 7437 C 1978 5.61 3.96 WEST 1954 16.04 14.39 Z 214 1963 8.08 6.43 S 190 RESET 1976 10.14 8.49
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 6 of 6 PUBLICATION DATE: 08/20/1991 Station ID: 8747437 SUPERCEDED DATE: 04/21/2003 Name: BAY WAVELAND YACHT CLUB, ST. LOUIS BAY MISSISSIPPI NOAA Chart: 11371 Latitude: 30° 19.5' N USGS Quad: BAY ST. LOUIS Longitude: 89° 19.5' W 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 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.