U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Datums Page Page 1 of 5 Station ID: 8577188 PUBLICATION DATE: 08/11/2003 Name: COVE POINT MD NOAA Chart: 12264 Latitude: 38° 23.5' N ( 38.39170) USGS Quad: COVE POINT Longitude: 76° 23.9' W ( -76.39830) To reach the tidal bench marks from bridge to Solomons Island on State Route 2-4 proceed north on State Route 2-4 to State Route 497, turn right onto State Route 497 and go to the Coast Guard Light Station at the end of the road. The bench marks are at the Coast Guard Light Station. The gage and tide staff were in the Columbia Liquified Natural Gas facilities to the north. T I D A L B E N C H M A R K S PRIMARY BENCH MARK STAMPING: NO 1 1972 DESIGNATION: 857 7188 TIDAL 1 MONUMENTATION: Tidal Station disk VM#: 3211 AGENCY: US Coast and Geodetic Survey (USC&GS) IDB PID#: SETTING CLASSIFICATION: Concrete steps OPUS PID: LATITUDE: 38° 23.5' N ( 38.39170) LONGITUDE: 76° 23.9' W ( -76.39830) The primary bench mark is a disk set flush in the concrete steps of a shed with large bell on the roof located on Cove Point at the Coast Guard Station, 8 m (27 ft) south of the lighthouse, and 8 m (25 ft) west of the seawall. BENCH MARK STAMPING: NO 2 1972 DESIGNATION: 857 7188 TIDAL 2 MONUMENTATION: Tidal Station disk VM#: 3212 AGENCY: US Coast and Geodetic Survey (USC&GS) IDB PID#: SETTING CLASSIFICATION: Steps OPUS PID: LATITUDE: 38° 23.5' N ( 38.39170) LONGITUDE: 76° 23.9' W ( -76.39830) The bench mark is a disk set flush in the steps at the NE corner of a duplex house (Coast Guard Families living quaters), 12 m (40 ft) NW of the lighthouse, and 11 m (35 ft) SW of a gate leading to the seawall.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 2 of 5 Station ID: 8577188 PUBLICATION DATE: 08/11/2003 Name: COVE POINT MD NOAA Chart: 12264 Latitude: 38° 23.5' N ( 38.39170) USGS Quad: COVE POINT Longitude: 76° 23.9' W ( -76.39830) T I D A L B E N C H M A R K S BENCH MARK STAMPING: NO 4 1972 DESIGNATION: 857 7188 TIDAL 4 MONUMENTATION: Tidal Station disk VM#: 3213 AGENCY: US Coast and Geodetic Survey (USC&GS) IDB PID#: SETTING CLASSIFICATION: Step OPUS PID: LATITUDE: 38° 23.5' N ( 38.39170) LONGITUDE: 76° 23.9' W ( -76.39830) The bench mark is a disk set flush in the first step of the rear entrance to a single family living quarter located SE of the main entrance gate, 46 m (150 ft) west of the lighthouse.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 3 of 5 Station ID: 8577188 PUBLICATION DATE: 08/11/2003 Name: COVE POINT MD NOAA Chart: 12264 Latitude: 38° 23.5' N ( 38.39170) USGS Quad: COVE POINT Longitude: 76° 23.9' W ( -76.39830) T I D A L B E N C H M A R K S BENCH MARK STAMPING: COVE BM DESIGNATION: COVE USN MONUMENTATION: Triangulation Station disk VM#: 3214 AGENCY: US Navy IDB PID#: HV0379 SETTING CLASSIFICATION: Concrete foundation OPUS PID: LATITUDE: 38° 23.1' N ( 38.38500) LONGITUDE: 76° 22.9' W ( -76.38170) The bench mark is a disk set flush in the NE concrete foundation of a tower used for a flagpole, 11.83 m (38.8 ft) west of the NW corner of the Coast Guard office building, 0.46 m (1.5 ft) SW of the NE corner of the concrete base for the NE leg of the flagpole base. BENCH MARK STAMPING: DESIGNATION: 857 7188 NO STAMPING 1 MONUMENTATION: Tidal Station disk VM#: 3215 AGENCY: Maryland Geological Survey (MDGS) IDB PID#: SETTING CLASSIFICATION: Concrete monument OPUS PID: LATITUDE: 38° 23.5' N ( 38.39170) LONGITUDE: 76° 23.9' W ( -76.39830) The bench mark is a disk set in a concrete monument located SW of lone tree in a clearing SSE of the Calvert Cliffs, south of the north end of the Liquified Natural Gas Pier, 111 m (365 ft) NW of the NW corner of the Coast Guard Property, 7.77 m (25.5 ft) SW of a lone tree, 5.94 m (19.5 ft) west of the vegetation-beach interface, and 0.18 m (0.6 ft) above the ground.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 4 of 5 Station ID: 8577188 PUBLICATION DATE: 08/11/2003 Name: COVE POINT MD NOAA Chart: 12264 Latitude: 38° 23.5' N ( 38.39170) USGS Quad: COVE POINT Longitude: 76° 23.9' W ( -76.39830) T I D A L D A T U M S Tidal datums at COVE POINT based on: LENGTH OF SERIES: 1 MONTH TIME PERIOD: November 1983 - November 1983 TIDAL EPOCH: 1983-2001 CONTROL TIDE STATION: 8575512 U.S. NAVAL ACADEMY, SEVERN R., CHES. BAY Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in METERS: MEAN HIGHER HIGH WATER MHHW = 0.420 MEAN HIGH WATER MHW = 0.344 MEAN SEA LEVEL MSL = 0.191 MEAN TIDE LEVEL MTL = 0.186 MEAN LOW WATER MLW = 0.028 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 1972 1.446 1.102 NO 2 1972 1.603 1.259 NO 4 1972 1.130 0.786 COVE BM 1.301 0.957 857 7188 NO STAMPING 1 1.649 1.305
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 5 of 5 Station ID: 8577188 PUBLICATION DATE: 08/11/2003 Name: COVE POINT MD NOAA Chart: 12264 Latitude: 38° 23.5' N ( 38.39170) USGS Quad: COVE POINT Longitude: 76° 23.9' W ( -76.39830) 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.