U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Datums Page Page 1 of 5 Station ID: 8744756 PUBLICATION DATE: 06/13/2003 Name: SHIP ISLAND, MISSISSIPPI SOUND MS NOAA Chart: 11372 Latitude: 30° 12.8' N ( 30.21330) USGS Quad: SHIP ISLAND Longitude: 88° 58.3' W ( -88.97170) To reach the tidal bench marks from the Gulfport Small Craft Harbor, proceed by boat on a heading of 145 magnetic degrees for 19.1 km (10.3 nm) to the west end of Ship Island where the National Park Service (NPS) maintains a pier. The bench marks are along the north-south walkway and east of the concession stand. The tide gage and staff were at the north end of the pier. T I D A L B E N C H M A R K S PRIMARY BENCH MARK STAMPING: 4756 A 1979 DESIGNATION: 874 4756 A MONUMENTATION: Tidal Station disk VM#: 10369 AGENCY: National Ocean Survey (NOS) IDB PID#: SETTING CLASSIFICATION: Stainless steel rod OPUS PID: LATITUDE: 30° 12.8' N ( 30.21330) LONGITUDE: 88° 58.3' W ( -88.97170) The primary bench mark is a disk located near the concession stand SE of Fort Massachusetts, 46 m (152 ft) south of the entrance to Fort Massachusetts, 21.18 m (69.5 ft) SE of the SE corner of Fort Massachusetts, 6.86 m (22.5 ft) NW of the NW corner of the concession building, and 0.3 m (1 ft) NE of the inside corner of the intersection of the main north-south wooden walkway and the walkway to the concession stand. The bench mark is set 9 cm (0.3 ft) below ground level, crimped to the top of a stainless steel rod driven 16.8 m (55 ft) to refusal, and encased in a PVC pipe and concrete kickblock.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 2 of 5 Station ID: 8744756 PUBLICATION DATE: 06/13/2003 Name: SHIP ISLAND, MISSISSIPPI SOUND MS NOAA Chart: 11372 Latitude: 30° 12.8' N ( 30.21330) USGS Quad: SHIP ISLAND Longitude: 88° 58.3' W ( -88.97170) T I D A L B E N C H M A R K S BENCH MARK STAMPING: SIGNAL 1966 DESIGNATION: SIGNAL AZ MK MONUMENTATION: Azimuth Mark disk VM#: 10368 AGENCY: US Coast and Geodetic Survey (USC&GS) IDB PID#: BH1905 SETTING CLASSIFICATION: Stainless steel rod OPUS PID#: BH1905 LATITUDE: 30° 12.6' N ( 30.20967) LONGITUDE: 88° 58.3' W ( -88.97211) The bench mark is a disk located about 299 m (981 ft) south of the entrance to Fort Massachusetts, 213 m (700 ft) north of the approximate waters edge on the south side of Ship Island as measured along the wooden walkway, 152 m (500 ft) north of the crest of the dune line on the south side of the island, and 12 m (41 ft) west of the centerline of the wooden walkway. The bench mark is set 1 m (2 ft) above grade, crimped to the top of a copper-clad steel rod driven to an unspecified depth, and encased in an asbestos pipe. BENCH MARK STAMPING: 4756 B 1979 DESIGNATION: 874 4756 B MONUMENTATION: Tidal Station disk VM#: 10370 AGENCY: National Ocean Survey (NOS) IDB PID#: SETTING CLASSIFICATION: Stainless steel rod OPUS PID: LATITUDE: 30° 12.8' N ( 30.21330) LONGITUDE: 88° 58.3' W ( -88.97170) The bench mark is a disk located east of the NW corner of the concession stand, 93 m (306 ft) SE of the entrance to old Fort Massachusetts, 65.38 m (214.5 ft) east along a wind fence line from bench mark 4756 A 1979, and 59 m (192 ft) east of the NW corner of the NPS concession building at the northern toe of the dune line on the Mississippi Sound side of the island, next to a witness sign. The bench mark is set 9 cm (0.3 ft) below ground level, crimped to the top of a stainless steel rod driven 15.2 m (50 ft) to refusal, and encased in a PVC pipe and concrete kickblock.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 3 of 5 Station ID: 8744756 PUBLICATION DATE: 06/13/2003 Name: SHIP ISLAND, MISSISSIPPI SOUND MS NOAA Chart: 11372 Latitude: 30° 12.8' N ( 30.21330) USGS Quad: SHIP ISLAND Longitude: 88° 58.3' W ( -88.97170) T I D A L B E N C H M A R K S BENCH MARK STAMPING: 4756 C 1979 DESIGNATION: 874 4756 C MONUMENTATION: Tidal Station disk VM#: 10371 AGENCY: National Ocean Survey (NOS) IDB PID#: SETTING CLASSIFICATION: Stainless steel rod OPUS PID: LATITUDE: 30° 12.8' N ( 30.21330) LONGITUDE: 88° 58.3' W ( -88.97170) The bench mark is a disk located on the crest of the dune line along the Mississippi Sound side of the island, 157 m (516 ft) SE of the entrance to Fort Massachusetts, 64 m (210 ft) east of bench mark 4756 B 1979, 28 m (92 ft) NW of a NPS weather station, and next to a witness post. The bench mark is set 12 cm (0.4 ft) below ground level, crimped to the top of a stainless steel rod driven 16.8 m (55 ft) to refusal, and encased in a PVC pipe and concrete kickblock. BENCH MARK STAMPING: 4756 D 1979 DESIGNATION: 874 4756 D MONUMENTATION: Tidal Station disk VM#: 10372 AGENCY: National Ocean Survey (NOS) IDB PID#: SETTING CLASSIFICATION: Stainless steel rod OPUS PID: LATITUDE: 30° 12.8' N ( 30.21330) LONGITUDE: 88° 58.3' W ( -88.97170) The bench mark is a disk located 149 m (490 ft) south along a wooden walkway across the island from the entrance to Fort Massachusetts, 103 m (338 ft) south of bench mark 4756 A 1979, 7 m (24 ft) west of the centerline of the wooden walkway on the crest of a sand dune line running along the axis of the center of the island, and next to a witness post. The bench mark is set 12 cm (0.4 ft) below grade, crimped to the top of a stainless steel rod driven 16.8 m (55 ft) to refusal, and encased in a PVC pipe and concrete kickblock.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 4 of 5 Station ID: 8744756 PUBLICATION DATE: 06/13/2003 Name: SHIP ISLAND, MISSISSIPPI SOUND MS NOAA Chart: 11372 Latitude: 30° 12.8' N ( 30.21330) USGS Quad: SHIP ISLAND Longitude: 88° 58.3' W ( -88.97170) T I D A L D A T U M S Tidal datums at SHIP ISLAND, MISSISSIPPI SOUND based on: LENGTH OF SERIES: 4 MONTHS TIME PERIOD: July 1980 - October 1980 TIDAL EPOCH: 1983-2001 CONTROL TIDE STATION: 8743735 BILOXI (CADET POINT), BILOXI BAY Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in METERS: MEAN HIGHER HIGH WATER MHHW = 0.513 MEAN HIGH WATER MHW = 0.476 MEAN SEA LEVEL MSL = 0.257 MEAN TIDE LEVEL MTL = 0.256 MEAN LOW WATER MLW = 0.035 MEAN LOWER LOW WATER MLLW = 0.000 North American Vertical Datum (NAVD88) Bench Mark Elevation Information In METERS above: Stamping or Designation MLLW MHW 4756 A 1979 1.328 0.852 SIGNAL 1966 1.690 1.214 4756 B 1979 1.271 0.795 4756 C 1979 1.705 1.229 4756 D 1979 1.307 0.831
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 5 of 5 Station ID: 8744756 PUBLICATION DATE: 06/13/2003 Name: SHIP ISLAND, MISSISSIPPI SOUND MS NOAA Chart: 11372 Latitude: 30° 12.8' N ( 30.21330) USGS Quad: SHIP ISLAND Longitude: 88° 58.3' W ( -88.97170) 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.