U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
Datums Page                                                        Page  1 of  8

                                                                                
Station ID: 8771450                                PUBLICATION DATE:  04/21/2003
Name:       GALVESTON PIER 21, GALVESTON CHANNEL              
            TEXAS
NOAA Chart: 11323                                  Latitude:         29° 18.6' N
USGS Quad:  GALVESTON                              Longitude:        94° 47.6' W


To reach the tidal bench marks from the Post Office on the west side of
Rosenberg Avenue (25th Street) between Winnie Street (Avenue G) on the south and
Church Street (Avenue F) on the north, proceed north on Rosenberg Avenue for
0.40 km (0.25 mi) to the intersection of Strand (Avenue B) and Rosenberg Avenue,
turn right on Strand and proceed east for 0.3 km (0.2 mi) to 22nd Street
(Kempner Avenue), then turn left and proceed north for 0.2 km (0.1 mi) to
Fishermans Wharf Restaurant.  The bench marks are on the seawall behind
Fishermans Wharf Restaurant, at the foot of 16th Street, on 20th Street, and on
Avenue B.  The tide gage and staff are on the north end of the dock for mooring
the historical ship ELLISA.


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


                 PRIMARY BENCH MARK STAMPING:  7.151
                         DESIGNATION:          7.151
                         ALIAS:                35 USE

MONUMENTATION:           Survey disk                               VM#:      843
AGENCY:                  US Army Corps of Engineers (USE)          PID#:  AW0433
SETTING CLASSIFICATION:  Sidewalk


The primary bench mark is a disk set in the sidewalk near the NE corner of the
Hendley Building at the corner of The Strand Street (Avenue B) and 20th Street,
12.00 m (39.4 ft) west of the centerline of 20th Street, 4.00 m (13.1 ft) south
of the centerline of the alley that runs behind the Hendley Building, and 0.10 m
( 0.3 ft) SE of the NE corner of the Hendley Building.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  2 of  8

                                                                                
Station ID: 8771450                                PUBLICATION DATE:  04/21/2003
Name:       GALVESTON PIER 21, GALVESTON CHANNEL              
            TEXAS
NOAA Chart: 11323                                  Latitude:         29° 18.6' N
USGS Quad:  GALVESTON                              Longitude:        94° 47.6' W


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


                         BENCH MARK STAMPING:  32 1913
                         DESIGNATION:          877 1450  TIDAL 32

MONUMENTATION:           Tidal Station disk                        VM#:      846
AGENCY:                  US Coast and Geodetic Survey (USC&GS)     PID#:  AW0436
SETTING CLASSIFICATION:  Granite base


The bench mark is a disk set in the top and along the east edge of the west
granite base of a pillar at the entrance of 2324 The Strand Street (Avenue B),
at the Sealy Building at the NE corner of the intersection of The Strand and
24th Street, 29.47 m (96.7 ft) east of the centerline of 24th Street, 12.19 m
(40.0 ft) north of the centerline of The Strand Street, 11.58 m (38.0 ft) west
of the SE corner of the building, 3.20 m (10.5 ft) west of the easterly most
column, and 0.46 m (1.5 ft) above the sidewalk.



                         BENCH MARK STAMPING:  J 305 1935
                         DESIGNATION:          J 305

MONUMENTATION:           Bench Mark disk                           VM#:      847
AGENCY:                  US Coast and Geodetic Survey (USC&GS)     PID#:  AW0437
SETTING CLASSIFICATION:  Building


The bench mark is a disk set vertically in the SE corner of the Shearn Moody
Plaza Building at the corner of 25th Street and Santa Fe Place, 16.79 m (55.1
ft) east of the center of a doorway entrance on the south side of the building,
12.20 m (40.0 ft) NNW of the centerline of Santa Fe Place, 5.91 m (19.4 ft) west
of the west curb of 25th Street, 1.01 m (3.3 ft) west of the SE corner of the
building, and 1.01 m (3.3 ft) above the sidewalk.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  3 of  8

                                                                                
Station ID: 8771450                                PUBLICATION DATE:  04/21/2003
Name:       GALVESTON PIER 21, GALVESTON CHANNEL              
            TEXAS
NOAA Chart: 11323                                  Latitude:         29° 18.6' N
USGS Quad:  GALVESTON                              Longitude:        94° 47.6' W


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


                         BENCH MARK STAMPING:  40 1935 RESET
                         DESIGNATION:          877 1450 TIDAL 40 RESET

MONUMENTATION:           Tidal Station disk                        VM#:      848
AGENCY:                  US Coast and Geodetic Survey (USC&GS)     PID#:  AW0569
SETTING CLASSIFICATION:  Concrete valve pit foundation


The bench mark is a disk set on the south edge of a 3.00 m x 3.00 m (9.8 ft x
9.8 ft) concrete valve pit foundation at the north end of 16th Street, in a
small triangular patch of grass at the NE side of a large parking lot for trucks
at the loading docks, 12.31 m (40.4 ft) SE of the NE corner of the scale, 10.40
m (34.1 ft) west of the western rail of the two parallel railroad tracks on the
west side of Pier 15, 9.70 m (31.8 ft) south of a power pole with two
transformers and a street light, 9.00 m (29.5 ft) ENE of the NE edge of the
concrete parking lot, 6.20 m (20.3 ft) north of the NW corner of a small metal
building for the scale, and 0.60 m (2.0 ft) west of a fiberglass witness post.



                         BENCH MARK STAMPING:  41 1935 RESET 1961
                         DESIGNATION:          877 1450 TIDAL 41 RESET

MONUMENTATION:           Tidal Station disk                        VM#:      849
AGENCY:                  US Coast and Geodetic Survey (USC&GS)     PID#:  AW0570
SETTING CLASSIFICATION:  Concrete column


The bench mark is a disk set vertically in the south face of the SE concrete
corner column of Pier 18 Building, 16.18 m (53.1 ft) west of the west side of
Pier 15 Warehouse, 14.20 m (46.6 ft) east of the center of DOOR 16, 0.30 m (1.0
ft) west of the SE corner of the warehouse, and 0.91 m (3.0 ft)  above the
loading platform.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  4 of  8

                                                                                
Station ID: 8771450                                PUBLICATION DATE:  04/21/2003
Name:       GALVESTON PIER 21, GALVESTON CHANNEL              
            TEXAS
NOAA Chart: 11323                                  Latitude:         29° 18.6' N
USGS Quad:  GALVESTON                              Longitude:        94° 47.6' W


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


                         BENCH MARK STAMPING:  42 1943
                         DESIGNATION:          877 1450  TIDAL 42

MONUMENTATION:           Tidal Station disk                        VM#:      850
AGENCY:                  US Coast and Geodetic Survey (USC&GS)     PID#:  AW0434
SETTING CLASSIFICATION:  Sea wall


The bench mark is a disk set in the top of the center of a sea wall behind the
Fishermans Wharf Restaurant at the north end of 22nd Street and the west end of
Pier 21, 9.36 m (30.7 ft) WSW of the SW face of the walk ramp to the Texas State
Museum, 7.50 m (24.6 ft) NNE of the second single cleat on the sea wall edge,
and 0.21 m (0.7 ft) SE of the edge of sea wall.



                         BENCH MARK STAMPING:  NO 2 1974
                         DESIGNATION:          877 1450 TIDAL 2

MONUMENTATION:           Tidal Station disk                        VM#:      851
AGENCY:                  National Ocean Survey (NOS)               PID#:  AW1894
SETTING CLASSIFICATION:  Concrete sea wall


The bench mark is a disk set flush in the top of a concrete sea wall behind the
Fisherman's Wharf Restaurant, Pier 22, at the north end of 22nd Street, 45.1 m
(148 ft) east of the NW corner of the Fisherman's Wharf Restaurant, 15.80 m
(51.7 ft) west of an angle point in the sea wall, and 0.27 m (0.9 ft) south of
the sea wall edge.   NOTE - mark is obstructed by a deck and can not be leveled.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  5 of  8

                                                                                
Station ID: 8771450                                PUBLICATION DATE:  04/21/2003
Name:       GALVESTON PIER 21, GALVESTON CHANNEL              
            TEXAS
NOAA Chart: 11323                                  Latitude:         29° 18.6' N
USGS Quad:  GALVESTON                              Longitude:        94° 47.6' W


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


                         BENCH MARK STAMPING:  1450 A 1989
                         DESIGNATION:          877 1450 A

MONUMENTATION:           Tidal Station disk                        VM#:      853
AGENCY:                  National Ocean Service (NOS)              PID:         
SETTING CLASSIFICATION:  Sidewalk


The bench mark is a disk set flush in the concrete apron at the NW corner of the
intersection of Harborside Drive and 20th Street, 22.40 m (73.5 ft) SE of the
southeasternmost light pole in the parking lot of Pier 21, 4.70 m (15.4 ft)
north of the north curb of Harborside Drive, 4.40 m (14.4 ft) west of the west
curb of 20th Street, and 0.21 m (0.7 ft) above the sidewalk.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  6 of  8

                                                                                
Station ID: 8771450                                PUBLICATION DATE:  04/21/2003
Name:       GALVESTON PIER 21, GALVESTON CHANNEL              
            TEXAS
NOAA Chart: 11323                                  Latitude:         29° 18.6' N
USGS Quad:  GALVESTON                              Longitude:        94° 47.6' W


                            T I D A L   D A T U M S 


Tidal datums at GALVESTON PIER 21, GALVESTON CHANNEL based on:

     LENGTH OF SERIES:      5 Years
     TIME PERIOD:           January 1997 - 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 (09/08/1900)         =  4.120
     MEAN HIGHER HIGH WATER                     MHHW   =  0.429
     MEAN HIGH WATER                            MHW    =  0.403
     MEAN SEA LEVEL                             MSL    =  0.252
     MEAN TIDE LEVEL                            MTL    =  0.248
     MEAN LOW WATER                             MLW    =  0.092
     North American Vertical Datum              NAVD88 =  0.043
     MEAN LOWER LOW WATER                       MLLW   =  0.000
     LOWEST  OBSERVED WATER LEVEL (01/11/1908)         = -1.915

North American Vertical Datum (NAVD88)

Bench Mark Elevation Information                In METERS above:

     Stamping or Designation                    MLLW        MHW

     7.151                                       1.520    1.117
     32 1913                                     2.069    1.666
     J 305 1935                                  2.268    1.865
     40 1935 RESET                               1.802    1.399
     41 1935 RESET 1961                          3.961    3.558
     42 1943                                     1.459    1.056
     NO 2 1974                                   1.450    1.047
     1450 A 1989                                 1.787    1.384


                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  7 of  8

                                                                                
Station ID: 8771450                                PUBLICATION DATE:  04/21/2003
Name:       GALVESTON PIER 21, GALVESTON CHANNEL              
            TEXAS
NOAA Chart: 11323                                  Latitude:         29° 18.6' N
USGS Quad:  GALVESTON                              Longitude:        94° 47.6' W


Foot Notes:

Galveston Bay, Texas has anomalous relative sea level trends compared to most
other geographic regions in the United States.  The is due to a general
subsidence of land in this area, which has been occurring at a rapid rate. 
Because of the magnitude of the sea level trends in these areas, NOAA has
adopted a procedure for computing accepted tidal datums for the National Water
Level Observation Network (NWLON) using the last several years of sea level data
rather than the 19 - year tidal epoch. The tide ranges are still based on the
1983 - 2001 National Tidal Datum Epoch (NTDE) and are applied to the five year
(1997 - 2001) mean tide level (MTL) to compute other tidal datums. The adoption
of this procedure was necessary to ensure that these tidal datums accurately
represent the existing stand of sea level.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  8 of  8

                                                                                
Station ID: 8771450                                PUBLICATION DATE:  04/21/2003
Name:       GALVESTON PIER 21, GALVESTON CHANNEL              
            TEXAS
NOAA Chart: 11323                                  Latitude:         29° 18.6' N
USGS Quad:  GALVESTON                              Longitude:        94° 47.6' 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.