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Bench Mark Sheet for 8577004, Long Beach MD

Superseded Epoch

Large map location marker Station Location
Small red map location marker Published bench mark
Small blue map location marker Unpublished bench mark

Bench mark positions only appear on the map if their coordinates in the CO-OPS database are at the precision of degrees/minutes/seconds/and tenths of seconds. If the coordinates are less precise, the mark will not appear.

Printable version

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
Datums Page                                                        Page  1 of  5

                                                                                
Station ID: 8577004                         PUBLICATION DATE:  02/05/2004
Name:       LONG BEACH, CHESAPEAKE BAY                        
            MD
NOAA Chart: 12264                           Latitude:   38° 27.9' N (  38.46500)
USGS Quad:  COVE POINT                      Longitude:  76° 28.4' W ( -76.47330)


To reach the tidal bench marks from the intersection of Maryland State Highway
2/4 and Calvert County Road (Calvert Beach Road), take Calvert Beach Road east
for 1.3 km (0.8 mi) to Long Beach Road, then turn right and proceed south on
Long Beach Road for 1.8 km (1.1 mi) to Flag Harbor Boulevard, then turn left and
proceed east on Flag Harbor Boulevard for 1.3 km (0.8 mi) to Flag Harbor Marina.
 The bench marks are located on the property of Flag Harbor Marina and residence
at 1594 Flag Harbor Boulevard.  The tide gage was located on the easternmost
finger pier on the south side of the parking lot near the end of Flag Harbor
Boulevard.


                         T I D A L   B E N C H   M A R K S


                 PRIMARY BENCH MARK STAMPING:  7004 C 1997
                         DESIGNATION:          857 7004 C

MONUMENTATION:           Tidal Station disk                    VM#:        13911
AGENCY:                  National Ocean Service (NOS)          IDB PID#:        
SETTING CLASSIFICATION:  Concrete slab                         OPUS PID:        
LATITUDE:   38° 27.9' N (  38.46500)          LONGITUDE:  76° 28.4' W ( -76.47330)


The primary bench mark is a disk set in the SE corner of a concrete pad on the
south side of a green pump house on the south side of Flag Harbor Boulevard, 9 m
(30 ft) west of a utility service panel with multiple electric meters labeled as
"Slip 19", 7 m (23 ft) NW of the center of a chain link fence gate at Slip 19,
and 5 m (17 ft) SE of a utility pole on the NW side of the green pump house.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  2 of  5

                                                                                
Station ID: 8577004                         PUBLICATION DATE:  02/05/2004
Name:       LONG BEACH, CHESAPEAKE BAY                        
            MD
NOAA Chart: 12264                           Latitude:   38° 27.9' N (  38.46500)
USGS Quad:  COVE POINT                      Longitude:  76° 28.4' W ( -76.47330)


                         T I D A L   B E N C H   M A R K S


                         BENCH MARK STAMPING:  7004 B 1997
                         DESIGNATION:          857 7004 B

MONUMENTATION:           Tidal Station disk                    VM#:        13910
AGENCY:                  National Ocean Service (NOS)          IDB PID#:        
SETTING CLASSIFICATION:  Concrete driveway                     OPUS PID:        
LATITUDE:   38° 27.9' N (  38.46500)          LONGITUDE:  76° 28.4' W ( -76.47330)


The bench mark is a disk set in the SE corner of a concrete driveway at 1594
Flag Harbor Boulevard, 12 m (38 ft) NW of an electric service panel with
multiple electric meters on the south side of the Boulevard, 12 m (38 ft) east
of the bottom step with black iron railing at 1594 Flag Harbor Boulevard, and 4
m (13 ft) west of a utility pole on the east side of the driveway.



                         BENCH MARK STAMPING:  7004 D 1997
                         DESIGNATION:          857 7004 D

MONUMENTATION:           Tidal Station disk                    VM#:        13912
AGENCY:                  National Ocean Service (NOS)          IDB PID#:        
SETTING CLASSIFICATION:  Concrete sidewalk                     OPUS PID#: BBDD60
LATITUDE:   38° 27.9' N (  38.46500)          LONGITUDE:  76° 28.4' W ( -76.47330)


The bench mark is a disk set in the west corner of the sidewalk leading to the
swimming pool and marina office at Flag Harbor Marina, 30 m (100 ft) SE of a
utility pole near the intersection of Flag Harbor Boulevard and Overlook Drive,
14 m (46 ft) SSW of the NW corner of the marina office building, and 9 m (28 ft)
WSW of a 1 m (3 ft) diameter concrete sewer cover with white PVC vent.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  3 of  5

                                                                                
Station ID: 8577004                         PUBLICATION DATE:  02/05/2004
Name:       LONG BEACH, CHESAPEAKE BAY                        
            MD
NOAA Chart: 12264                           Latitude:   38° 27.9' N (  38.46500)
USGS Quad:  COVE POINT                      Longitude:  76° 28.4' W ( -76.47330)


                         T I D A L   B E N C H   M A R K S


                         BENCH MARK STAMPING:  7004 E 1997
                         DESIGNATION:          857 7004 E

MONUMENTATION:           Tidal Station disk                    VM#:        13913
AGENCY:                  National Ocean Service (NOS)          IDB PID#:        
SETTING CLASSIFICATION:  Concrete step                         OPUS PID:        
LATITUDE:   38° 27.9' N (  38.46500)          LONGITUDE:  76° 28.4' W ( -76.47330)


The bench mark is a disk set in a concrete step on the east side of the picnic
pavilion at Flag Harbor Marina, 20 m (65 ft) ENE of a flag pole in a green space
south of the office, 18 m (58 ft) south of the marina office front door on the
east side of the building, and 9 m (28 ft) NE of the SE corner of a chain link
fence enclosing the swimming pool.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  4 of  5

                                                                                
Station ID: 8577004                         PUBLICATION DATE:  02/05/2004
Name:       LONG BEACH, CHESAPEAKE BAY                        
            MD
NOAA Chart: 12264                           Latitude:   38° 27.9' N (  38.46500)
USGS Quad:  COVE POINT                      Longitude:  76° 28.4' W ( -76.47330)


                            T I D A L   D A T U M S 


Tidal datums at LONG BEACH, CHESAPEAKE BAY based on:

     LENGTH OF SERIES:      30 MONTHS
     TIME PERIOD:           November 1997 - April 2000
     TIDAL EPOCH:           1983-2001
     CONTROL TIDE STATION:  8577330 SOLOMONS ISLAND, PATUXENT RIVER


Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in METERS:

     HIGHEST OBSERVED WATER LEVEL (02/06/1998)         =  1.015
     MEAN HIGHER HIGH WATER                     MHHW   =  0.409
     MEAN HIGH WATER                            MHW    =  0.359
     MEAN SEA LEVEL                             MSL    =  0.208
     MEAN TIDE LEVEL                            MTL    =  0.205
     MEAN LOW WATER                             MLW    =  0.051
     MEAN LOWER LOW WATER                       MLLW   =  0.000
     LOWEST  OBSERVED WATER LEVEL (01/01/1998)         = -0.630

North American Vertical Datum (NAVD88)

Bench Mark Elevation Information                In METERS above:

     Stamping or Designation                    MLLW        MHW

     7004 C 1997                                 1.879    1.520
     7004 B 1997                                 3.457    3.098
     7004 D 1997                                 7.786    7.427
     7004 E 1997                                 6.215    5.856


                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  5 of  5

                                                                                
Station ID: 8577004                         PUBLICATION DATE:  02/05/2004
Name:       LONG BEACH, CHESAPEAKE BAY                        
            MD
NOAA Chart: 12264                           Latitude:   38° 27.9' N (  38.46500)
USGS Quad:  COVE POINT                      Longitude:  76° 28.4' W ( -76.47330)


                             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.

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Products available at 8577004 Long Beach, MD

Revised: 08/08/2018
NOAA / National Ocean Service
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