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.