U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
Datums Page                                                        Page  1 of  7

                                                                                
Station ID: 8638610                                PUBLICATION DATE:  08/07/2013
Name:       SEWELLS POINT, HAMPTON ROADS                      
            VA
NOAA Chart: 12245                                  Latitude:         36° 56.8' N
USGS Quad:  NORFOLK NORTH                          Longitude:        76° 19.8' W


To reach the tidal bench marks from the Field Operations Division (FOD) office
in Chesapeake, VA. proceed to Interstate 64 west towards Norfolk and take I-564
to the Naval Base and Tausigg Blvd. Take Tausigg Blvd. to Gate 2 and follow
Decatur Avenue around to Pier 6. Tide gauge is located near the south end of
Pier 6, and the bench marks are in the vicinity of Pier 6 and Piersey Street.


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


                 PRIMARY BENCH MARK STAMPING:  8610 G 2006
                         DESIGNATION:          863 8610 G

MONUMENTATION:           Tidal Station disk                        VM#:    18111
AGENCY:                  National Ocean Service (NOS)              PID:         
SETTING CLASSIFICATION:  Pier


The primary bench mark is disk set in a pier, 51.20 m (168.0 ft) south of the
second bollard along the bulkhead, 38.22 m (125.39 ft) west of the centerline of
Decatur Street, 37.45 m (122.9 ft) north of the NE corner of pier 6, 0.30 m (1.0
ft) east of the west face of the bulkhead, and 0.24 m (0.8 ft) above the
concrete parking lot.



                         BENCH MARK STAMPING:  8610 F 2006
                         DESIGNATION:          863 8610 F

MONUMENTATION:           Tidal Station disk                        VM#:    18112
AGENCY:                  National Ocean Service (NOS)              PID:         
SETTING CLASSIFICATION:  Concrete pier


The bench mark is a disk set in a concrete pier, 6.80 m (22.3 ft) north of the
south face of the concrete pier, 4.90 m (16.1 ft) west of the western edge of a
cleat on the east face of the concrete pier, and 0.35 m (1.1 ft) east of the
eastern edge of a cleat on the west face of the concrete pier.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  2 of  7

                                                                                
Station ID: 8638610                                PUBLICATION DATE:  08/07/2013
Name:       SEWELLS POINT, HAMPTON ROADS                      
            VA
NOAA Chart: 12245                                  Latitude:         36° 56.8' N
USGS Quad:  NORFOLK NORTH                          Longitude:        76° 19.8' W


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


                         BENCH MARK STAMPING:  8610 H 2009
                         DESIGNATION:          863 8610 H

MONUMENTATION:           Tidal Station disk                        VM#:    19456
AGENCY:                  National Ocean Survey/Service (NOS)       PID:         
SETTING CLASSIFICATION:  Concrete naval pier


The bench mark is set in the edge of a massive concrete pier, 21.80 m (71.5 ft)
north of the north face of Pier 7, 18.3 m (60.0 ft) south of a steel cleat on
the western edge of a pier wall, 0.48 m (1.6 ft) east of the west face of pier
wall, and 0.31 m (1.0 ft) above the ground.



                         BENCH MARK STAMPING:  8610 J 2009
                         DESIGNATION:          863 8610 J

MONUMENTATION:           Tidal Station disk                        VM#:    19457
AGENCY:                  National Ocean Survey/Service(NOS)        PID:         
SETTING CLASSIFICATION:  Concrete naval pier


The bench mark is 14.43 m (47.3 ft) NE of NE corner of warehouse building, 10.52
m (34.5 ft) WNW of centerline of Decatur Avenue, 6.20 m (20.3 ft) ESE of
westerly face of pier wall, and 0.12 m (0.4 ft) above ground.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  3 of  7

                                                                                
Station ID: 8638610                                PUBLICATION DATE:  08/07/2013
Name:       SEWELLS POINT, HAMPTON ROADS                      
            VA
NOAA Chart: 12245                                  Latitude:         36° 56.8' N
USGS Quad:  NORFOLK NORTH                          Longitude:        76° 19.8' W


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


                         BENCH MARK STAMPING:  8610 K 2009
                         DESIGNATION:          863 8610 K

MONUMENTATION:           Tidal Station disk                        VM#:    19458
AGENCY:                  National Ocean Survey/Service(NOS)        PID:         
SETTING CLASSIFICATION:  Concrete naval pier


The bench mark is set in the concrete pier wall on the east side of the small
boats warehouse, 18.23 m (59.8 ft) SW of the centerline of Decatur Ave/Admiral
Taussig Boulevard, 1.48 m (4.9 ft) east of the NE corner of the small boats
warehouse, and 0.32 m (1.0 ft) north of the southerly face of pier wall.



                         BENCH MARK STAMPING:  8610 L 2010
                         DESIGNATION:          863 8610 L

MONUMENTATION:           Tidal Station disk                        VM#:    19648
AGENCY:                  NOS                                       PID:         
SETTING CLASSIFICATION:  Concrete naval pier


Bench mark is a survey disc set in the concrete pier on the Norfolk naval base,
4.38 m (14.4 ft) southwest from the southwest corner of the NNSY divers
underwater repair building, 0.60 m (2.0 ft) east from the pier face running
north and south on the west side of the NNSY building, 0.60 m (2.0 ft) north
from the pier face bulkhead running east and west on the south side of NNSY
building.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  4 of  7

                                                                                
Station ID: 8638610                                PUBLICATION DATE:  08/07/2013
Name:       SEWELLS POINT, HAMPTON ROADS                      
            VA
NOAA Chart: 12245                                  Latitude:         36° 56.8' N
USGS Quad:  NORFOLK NORTH                          Longitude:        76° 19.8' W


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


                         BENCH MARK STAMPING:  8610 M 2010
                         DESIGNATION:          863 8610 M

MONUMENTATION:           Tidal Station disk                        VM#:    19649
AGENCY:                  NOS                                       PID:         
SETTING CLASSIFICATION:  Concrete nabal pier


The bench mark is set flush in the top retaining wall bulkhead near the east end
by the double gate leading to boat staging area, 10.55 m (34.6 ft) west from
fire hydrant number 1236 on west side of double gate leading to boat staging
area, 4.60 m (15.1 ft) north from a 0.66 m (2.2 ft) boat cleat on the northern
end of bulkhead running parallel to Second St, 0.85 m (2.8 ft) east from
centerline of ladder attached to bulkhead face of the pier running parallel with
admiral Tussig boulevard, set 0.25 m (0.8 ft) above the ground.



                         BENCH MARK STAMPING:  8610 N 2010
                         DESIGNATION:          863 8610 N

MONUMENTATION:           Tidal Station disk                        VM#:    19650
AGENCY:                  NOS                                       PID:         
SETTING CLASSIFICATION:  Concrete naval pier


Bench mark is set flush in concrete base at southeast corner of the fleet and
industrial supply center sign at intersection of Decatur avenue and Gilbert St
on northeast corner set in sign footing, 11.45 m (37.6 ft) north from the center
line Gilbert St, 4.27 m (14.0 ft) west from the southwest pillar holding up the
fleet center supply sign, 03.0 m (9.8 ft) south from the northeast pillar
holding up fleet center supply sign, 0.20 m (0.7 ft) above the ground.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  5 of  7

                                                                                
Station ID: 8638610                                PUBLICATION DATE:  08/07/2013
Name:       SEWELLS POINT, HAMPTON ROADS                      
            VA
NOAA Chart: 12245                                  Latitude:         36° 56.8' N
USGS Quad:  NORFOLK NORTH                          Longitude:        76° 19.8' W


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


                         BENCH MARK STAMPING:  8610 P 2010
                         DESIGNATION:          863 8610 P

MONUMENTATION:           Tidal Station disk                        VM#:    19651
AGENCY:                  NOS                                       PID:         
SETTING CLASSIFICATION:  Concrete naval pier


Bench mark is set flush in the concrete base pad of a bus stop shelter located
at the southwest corner of fleet supply building located on the southeast corner
of the bus shelter, 6.29 m (20.6 ft) southwest from the southwest corner of the
fleet supply building, 2.66 m (8.7 ft) east from the southwest corner of bus
shelter concrete pad, 0.09 m (0.3 ft) west from the southeast corner of bus
shelter concrete pad, 0.18 m (0.6 ft) above ground.    



                         BENCH MARK STAMPING:  8610 R 2010
                         DESIGNATION:          863 8610 R

MONUMENTATION:           Tidal Station disk                        VM#:    19652
AGENCY:                  NOS                                       PID:         
SETTING CLASSIFICATION:  Concrete naval pier


Bench mark is set flush in the concrete sidewalk of the entrance to the fleet
industrial supply center building, 3.17 m (10.4 ft) south of main powered door,
1.19 m (3.9 ft) east from the southwest corner of sidewalk, 0.19 m (0.6 ft)
north from the south edge of the sidewalk, 0.10 m (0.3 ft) above ground.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  6 of  7

                                                                                
Station ID: 8638610                                PUBLICATION DATE:  08/07/2013
Name:       SEWELLS POINT, HAMPTON ROADS                      
            VA
NOAA Chart: 12245                                  Latitude:         36° 56.8' N
USGS Quad:  NORFOLK NORTH                          Longitude:        76° 19.8' W


                            T I D A L   D A T U M S 


Tidal datums at SEWELLS POINT, HAMPTON ROADS based on:

     LENGTH OF SERIES:      19 YEARS
     TIME PERIOD:           January 1983 - December 2001
     TIDAL EPOCH:           1983-2001
     CONTROL TIDE STATION:   


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

     HIGHEST OBSERVED WATER LEVEL (08/23/1933)         =  2.444
     MEAN HIGHER HIGH WATER                     MHHW   =  0.840
     MEAN HIGH WATER                            MHW    =  0.778
     North American Vertical Datum              NAVD88 =  0.491
     MEAN SEA LEVEL                             MSL    =  0.412
     MEAN TIDE LEVEL                            MTL    =  0.408
     MEAN LOW WATER                             MLW    =  0.038
     MEAN LOWER LOW WATER                       MLLW   =  0.000
     LOWEST  OBSERVED WATER LEVEL (01/31/1966)         = -1.092



Bench Mark Elevation Information                In METERS above:

     Stamping or Designation                    MLLW        MHW

     8610 G 2006                                 2.978    2.200
     8610 F 2006                                 2.712    1.934
     8610 H 2009                                 2.984    2.206
     8610 J 2009                                 2.916    2.138
     8610 K 2009                                 2.969    2.191
     8610 L 2010                                 2.539    1.761
     8610 M 2010                                 2.976    2.198
     8610 N 2010                                 2.976    2.198
     8610 P 2010                                 2.975    2.197
     8610 R 2010                                 2.872    2.094


                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  7 of  7

                                                                                
Station ID: 8638610                                PUBLICATION DATE:  08/07/2013
Name:       SEWELLS POINT, HAMPTON ROADS                      
            VA
NOAA Chart: 12245                                  Latitude:         36° 56.8' N
USGS Quad:  NORFOLK NORTH                          Longitude:        76° 19.8' W


                             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 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.