U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Datums Page Page 1 of 7 Station ID: 8574821 PUBLICATION DATE: 12/12/2003 Name: HAWKINS POINT MD NOAA Chart: 12281 Latitude: 39° 12.5' N ( 39.20830) USGS Quad: CURTIS BAY Longitude: 76° 32.0' W ( -76.53330) To reach the tidal bench marks from the intersection of State Highway 2 (Governor Ritchie Highway) and State Highway 710 (Ordinance Road) in Glen Burnie, proceed ENE on State Highway 710 for 3.5 km (2.2 mi) to State Highway 170 (Fort Smallwood Road), then turn right and proceed NE on State Highway 170 for 3.1 km (1.9 mi) to Fort Armistead Road, then turn left and proceed NW on Fort Armistead Road for 1.8 km (1.1 mi), then turn right and continue for 0.2 km (0.1 mi), then turn left onto a dirt road and go 0.6 km (0.4 mi) to the end of the road. The bench marks are on the sea wall. The tide gage and staff were on the city owned pier. T I D A L B E N C H M A R K S PRIMARY BENCH MARK STAMPING: NO 1 1975 DESIGNATION: 857 4821 TIDAL 1 MONUMENTATION: Tidal Station disk VM#: 3185 AGENCY: National Ocean Survey (NOS) IDB PID#: SETTING CLASSIFICATION: Concrete sea wall OPUS PID: LATITUDE: 39° 12.5' N ( 39.20831) LONGITUDE: 76° 31.9' W ( -76.53169) The primary bench mark is a disk set flush in the concrete sea wall at the foot of the city pier, about 2 m (5 ft) from the north fence gate post, and 0.61 m (2.0 ft) west of the edge of the sea wall.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 2 of 7 Station ID: 8574821 PUBLICATION DATE: 12/12/2003 Name: HAWKINS POINT MD NOAA Chart: 12281 Latitude: 39° 12.5' N ( 39.20830) USGS Quad: CURTIS BAY Longitude: 76° 32.0' W ( -76.53330) T I D A L B E N C H M A R K S BENCH MARK STAMPING: DESIGNATION: 857 4821 TIDAL 3 ALIAS: NO STAMPING 1 MONUMENTATION: See descriptive text VM#: 3186 AGENCY: National Ocean Survey (NOS) IDB PID#: SETTING CLASSIFICATION: Concrete sea wall OPUS PID: LATITUDE: 39° 12.5' N ( 39.20831) LONGITUDE: 76° 31.9' W ( -76.53169) The bench mark is a chiseled point marked by a white painted circle on the concrete sea wall, 40 m (130 ft) NNE of bench mark NO 1 1975.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 3 of 7 Station ID: 8574821 PUBLICATION DATE: 12/12/2003 Name: HAWKINS POINT MD NOAA Chart: 12281 Latitude: 39° 12.5' N ( 39.20830) USGS Quad: CURTIS BAY Longitude: 76° 32.0' W ( -76.53330) T I D A L B E N C H M A R K S BENCH MARK STAMPING: DESIGNATION: 857 4821 TIDAL 4 ALIAS: NO STAMPING 2 MONUMENTATION: Nail VM#: 3187 AGENCY: National Ocean Survey (NOS) IDB PID#: SETTING CLASSIFICATION: Concrete sea wall OPUS PID: LATITUDE: 39° 12.5' N ( 39.20831) LONGITUDE: 76° 31.9' W ( -76.53169) The bench mark is a masonry nail driven into the concrete sea wall and marked "BUCK" with white painted letters, and 30 m (100 ft) north of bench mark 857 4821 TIDAL 3.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 4 of 7 Station ID: 8574821 PUBLICATION DATE: 12/12/2003 Name: HAWKINS POINT MD NOAA Chart: 12281 Latitude: 39° 12.5' N ( 39.20830) USGS Quad: CURTIS BAY Longitude: 76° 32.0' W ( -76.53330) T I D A L B E N C H M A R K S BENCH MARK STAMPING: DESIGNATION: 857 4821 TIDAL 2 ALIAS: NO STAMPING 3 MONUMENTATION: Nail VM#: 17049 AGENCY: National Ocean Survey (NOS) IDB PID#: SETTING CLASSIFICATION: Pavement OPUS PID: LATITUDE: 39° 12.5' N ( 39.20831) LONGITUDE: 76° 31.9' W ( -76.53169) The bench mark is a nail driven into and flush with the pavement at the SE corner of a tin shed, 15 m (50 ft) SW of bench mark NO 1 1975, 0.3 m (1 ft) from the SE corner of the tin shed. NOTE: A white painted circle indicates the location of the nail.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 5 of 7 Station ID: 8574821 PUBLICATION DATE: 12/12/2003 Name: HAWKINS POINT MD NOAA Chart: 12281 Latitude: 39° 12.5' N ( 39.20830) USGS Quad: CURTIS BAY Longitude: 76° 32.0' W ( -76.53330) T I D A L B E N C H M A R K S BENCH MARK STAMPING: DESIGNATION: 857 4821 TIDAL 5 ALIAS: NO STAMPING 4 MONUMENTATION: Nail VM#: 17050 AGENCY: National Ocean Survey (NOS) IDB PID#: SETTING CLASSIFICATION: Tree trunk OPUS PID: LATITUDE: 39° 12.5' N ( 39.20831) LONGITUDE: 76° 31.9' W ( -76.53169) The bench mark is a nail driven into the SE side of the trunk of a large tree, 67 m (220 ft) NW of bench mark 857 4821 TIDAL 4, 5 m (15 ft) SW of the sea wall, and 0.3 m (1.0 ft) above the ground.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 6 of 7 Station ID: 8574821 PUBLICATION DATE: 12/12/2003 Name: HAWKINS POINT MD NOAA Chart: 12281 Latitude: 39° 12.5' N ( 39.20830) USGS Quad: CURTIS BAY Longitude: 76° 32.0' W ( -76.53330) T I D A L D A T U M S Tidal datums at HAWKINS POINT based on: LENGTH OF SERIES: 1 MONTH TIME PERIOD: September 1976 - September 1976 TIDAL EPOCH: 1983-2001 CONTROL TIDE STATION: 8574680 BALTIMORE, FORT MCHENRY, PATAPSCO RIVER Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in METERS: MEAN HIGHER HIGH WATER MHHW = 0.524 MEAN HIGH WATER MHW = 0.425 MEAN SEA LEVEL MSL = 0.250 MEAN TIDE LEVEL MTL = 0.244 MEAN LOW WATER MLW = 0.063 MEAN LOWER LOW WATER MLLW = 0.000 North American Vertical Datum (NAVD88) Bench Mark Elevation Information In METERS above: Stamping or Designation MLLW MHW NO 1 1975 1.635 1.210 857 4821 TIDAL 3 1.609 1.184 857 4821 TIDAL 4 1.652 1.227 857 4821 TIDAL 2 2.182 1.757 857 4821 TIDAL 5 1.992 1.567 Foot Notes: Bench mark 8574821 TIDAL 5 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 an elevation for this mark.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 7 of 7 Station ID: 8574821 PUBLICATION DATE: 12/12/2003 Name: HAWKINS POINT MD NOAA Chart: 12281 Latitude: 39° 12.5' N ( 39.20830) USGS Quad: CURTIS BAY Longitude: 76° 32.0' W ( -76.53330) 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.