U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
Datums Page                                                        Page  1 of  9

                                                                                
Station ID: 8771450                         PUBLICATION DATE:  12/09/2019
Name:       GALVESTON PIER 21, GALVESTON CHANNEL              
            TX
NOAA Chart: 11323                           Latitude:   29° 18.6' N (  29.31000)
USGS Quad:  GALVESTON                       Longitude:  94° 47.6' W ( -94.79331)


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 0.57 km (0.35 mi) to 20th street. Turn
left on to 20th street and travel 0.28 km (0.17 mi) north to end of street. The
station is located North East from the end of 20th street.


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


                 PRIMARY BENCH MARK STAMPING:  1450 B 2002
                         DESIGNATION:          877 1450 B

MONUMENTATION:           Flange-encased Rod                    VM#:        17155
AGENCY:                  National Ocean Service (NOS)          IDB PID:         
SETTING CLASSIFICATION:  Stainless steel rod                   OPUS PID#: DO9996
LATITUDE:   29° 18.6' N (  29.30939)          LONGITUDE:  94° 47.5' W ( -94.79200)


The primary bench mark is a flange-encased rod located in Pier 21 block near
Harborside Drive, 38.1 m (125.0 ft) east of the ENE corner of No.28 building in
which Harbor House Hotel is located, 32.5 m (106.6 ft) SW of a utility pole
marked "TP 15330", 5.7 m (18.7 ft) SE of the centerline of railroad tracks
running parallel with through street, and 0.6 m (2.0 ft) NE of a corner in a
curb enclosing a paid parking lot. The datum point is the top of a stainless
steel rod driven 14.6 m (47.9 ft) to refusal and encased in a 6 inch NOS logo
cap with a concrete kickblock..

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  2 of  9

                                                                                
Station ID: 8771450                         PUBLICATION DATE:  12/09/2019
Name:       GALVESTON PIER 21, GALVESTON CHANNEL              
            TX
NOAA Chart: 11323                           Latitude:   29° 18.6' N (  29.31000)
USGS Quad:  GALVESTON                       Longitude:  94° 47.6' W ( -94.79331)


                         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)                              IDB PID#:  AW0436
SETTING CLASSIFICATION:  Granite base                          OPUS PID:        
LATITUDE:   29° 18.4' N (  29.30694)          LONGITUDE:  94° 47.7' W ( -94.79528)


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.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  3 of  9

                                                                                
Station ID: 8771450                         PUBLICATION DATE:  12/09/2019
Name:       GALVESTON PIER 21, GALVESTON CHANNEL              
            TX
NOAA Chart: 11323                           Latitude:   29° 18.6' N (  29.31000)
USGS Quad:  GALVESTON                       Longitude:  94° 47.6' W ( -94.79331)


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


                         BENCH MARK STAMPING:  J 305 1935
                         DESIGNATION:          J 305

MONUMENTATION:           Bench Mark disk                       VM#:          847
AGENCY:                  US Coast and Geodetic Survey
                         (USC&GS)                              IDB PID#:  AW0437
SETTING CLASSIFICATION:  Building                              OPUS PID:        
LATITUDE:   29° 18.4' N (  29.30618)          LONGITUDE:  94° 47.8' W ( -94.79677)


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.



                         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)                              IDB PID#:  AW0569
SETTING CLASSIFICATION:  Concrete valve pit foundation         OPUS PID:        
LATITUDE:   29° 18.7' N (  29.31164)          LONGITUDE:  94° 47.2' W ( -94.78700)


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.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  4 of  9

                                                                                
Station ID: 8771450                         PUBLICATION DATE:  12/09/2019
Name:       GALVESTON PIER 21, GALVESTON CHANNEL              
            TX
NOAA Chart: 11323                           Latitude:   29° 18.6' N (  29.31000)
USGS Quad:  GALVESTON                       Longitude:  94° 47.6' W ( -94.79331)


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


                         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)                              IDB PID#:  AW0570
SETTING CLASSIFICATION:  Concrete column                       OPUS PID:        
LATITUDE:   29° 18.8' N (  29.31278)          LONGITUDE:  94° 47.2' W ( -94.78694)


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.



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

MONUMENTATION:           Bench Mark disk                       VM#:          853
AGENCY:                  National Ocean Service (NOS)          IDB PID:         
SETTING CLASSIFICATION:  Sidewalk                              OPUS PID:        
LATITUDE:   29° 18.5' N (  29.30897)          LONGITUDE:  94° 47.5' W ( -94.79144)


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 (73.491 ft) SE of the
southeasternmost light pole in the parking lot of Pier 21, 4.70 m (15.42 ft)
north of the north curb of Harborside Drive, 4.40 m (14.44 ft) west of the west
curb of 20th Street, and 0.21 m (0.69 ft) above the sidewalk.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  5 of  9

                                                                                
Station ID: 8771450                         PUBLICATION DATE:  12/09/2019
Name:       GALVESTON PIER 21, GALVESTON CHANNEL              
            TX
NOAA Chart: 11323                           Latitude:   29° 18.6' N (  29.31000)
USGS Quad:  GALVESTON                       Longitude:  94° 47.6' W ( -94.79331)


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


                         BENCH MARK STAMPING:  1450 C 2002
                         DESIGNATION:          877 1450 C

MONUMENTATION:           Flange-encased Rod                    VM#:        17156
AGENCY:                  National Ocean Service (NOS)          IDB PID:         
SETTING CLASSIFICATION:  Stainless steel rod                   OPUS PID#: BBDS68
LATITUDE:   29° 18.5' N (  29.30892)          LONGITUDE:  94° 47.6' W ( -94.79331)


The bench mark is a flange-encased rod located near the entrance to the Texas
Seaport Museum, 26.2 m (86.0 ft) SW of a utility pole marked "81HJ25T+316024",
21.7 m (71.2 ft) east of a railroad track switch, 11.0 m (36.1 ft) NW of a
utility pole marked "2TR40T" in the bricked median between trolley tracks and
railroad tracks, 10.6 m (34.8 ft) south of a utility pole marked "277480", and
1.32 m (4.33 ft) west of the west side of a median curb. The datum point is the
top of a stainless steel rod driven 15.24 m (50.00 ft) to refusal and encased in
a 6 inch NOS logo cap with a concrete kickblock.



                         BENCH MARK STAMPING:  1450 D 2005
                         DESIGNATION:          877 1450 D

MONUMENTATION:           Tidal Station disk                    VM#:        17791
AGENCY:                  Department of Nearshore research (DNR) IDB PID:         
SETTING CLASSIFICATION:  Sidewalk                              OPUS PID:        
LATITUDE:   29° 18.6' N (  29.30954)          LONGITUDE:  94° 47.4' W ( -94.78938)


The bench mark is set into the top of the concrete sidewalk running along the
south side of the UTMB building on Harborside Dr., located 23.8 m (78.1 ft) east
of the SE corner of the University of Texas Medical Branch Administration Office
Building, 11.5 m (37.7 ft) south of the centerline of Harborside Dr., 2.0 m (6.6
ft) north of the sidewalk/curb on the north side of Harborside Drive.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  6 of  9

                                                                                
Station ID: 8771450                         PUBLICATION DATE:  12/09/2019
Name:       GALVESTON PIER 21, GALVESTON CHANNEL              
            TX
NOAA Chart: 11323                           Latitude:   29° 18.6' N (  29.31000)
USGS Quad:  GALVESTON                       Longitude:  94° 47.6' W ( -94.79331)


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


                         BENCH MARK STAMPING:  1450 E 2005
                         DESIGNATION:          877 1450 E

MONUMENTATION:           Tidal Station disk                    VM#:        17792
AGENCY:                  Department of Nearshore Research (DNR) IDB PID:         
SETTING CLASSIFICATION:  Concrete drain culvert                OPUS PID:        
LATITUDE:   29° 18.5' N (  29.30830)          LONGITUDE:  94° 47.6' W ( -94.79330)


The bench mark is set atop the concrete drain culvert located on the north side
of Harborside Drive,  12.6 m (41.3 ft) west of the centerline of 17th street,
5.1 m (16.7 ft) north of the centerline of Harborside Dr., and 5.1 m (16.7 ft)
south of the elevetated parking lot at the Coors beer terminal.



                         BENCH MARK STAMPING:  1450 F 2005
                         DESIGNATION:          877 1450 F

MONUMENTATION:           Tidal Station disk                    VM#:        17793
AGENCY:                  Department of Nearshore Research (DNR) IDB PID:         
SETTING CLASSIFICATION:  Sidewalk                              OPUS PID:        
LATITUDE:   29° 18.5' N (  29.30830)          LONGITUDE:  94° 47.5' W ( -94.79170)


The bench mark is set into the top of the concrete step west of a trash
receptical concreted next to Kempner St., located 11.7 m (38.4 ft) south of the
Strand St., 7.2 m (23.6 ft) east of the centerline of Kempner,  and 4.6 m (15.1
ft) north of the concrete sidewalk on the north side of Strand Street.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  7 of  9

                                                                                
Station ID: 8771450                         PUBLICATION DATE:  12/09/2019
Name:       GALVESTON PIER 21, GALVESTON CHANNEL              
            TX
NOAA Chart: 11323                           Latitude:   29° 18.6' N (  29.31000)
USGS Quad:  GALVESTON                       Longitude:  94° 47.6' W ( -94.79331)


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


                         BENCH MARK STAMPING:  1450 G 2013
                         DESIGNATION:          877 1450 G

MONUMENTATION:           Bench Mark disk                       VM#:        20665
AGENCY:                  National Ocean Service (NOS)          IDB PID:         
SETTING CLASSIFICATION:  concrete wharf                        OPUS PID:        
LATITUDE:   29° 18.6' N (  29.31047)          LONGITUDE:  94° 47.5' W ( -94.79189)


The bench mark is a disk set into the concrete wharf, 18.5m (60.7 ft) north of
the first light pole located west of the oil rig museum gift shop, 41.5m (136.2
ft) NE of the second light pole from the gift shop, 9.78m (32.1 ft) W of the
tide station, and 0.61m (2.0 ft) S of the bulkhead.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  8 of  9

                                                                                
Station ID: 8771450                         PUBLICATION DATE:  12/09/2019
Name:       GALVESTON PIER 21, GALVESTON CHANNEL              
            TX
NOAA Chart: 11323                           Latitude:   29° 18.6' N (  29.31000)
USGS Quad:  GALVESTON                       Longitude:  94° 47.6' W ( -94.79331)


                            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
     North American Vertical Datum              NAVD88 =  0.094
     MEAN LOW WATER                             MLW    =  0.092
     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

     1450 B 2002                                 1.889    1.486
     32 1913                                     2.068    1.665
     J 305 1935                                  2.268    1.865
     40 1935 RESET                               1.809    1.406
     41 1935 RESET 1961                          3.969    3.566
     1450 A 1989                                 1.790    1.387
     1450 C 2002                                 1.819    1.416
     1450 D 2005                                 1.544    1.141
     1450 E 2005                                 1.259    0.856
     1450 F 2005                                 1.714    1.311
     1450 G 2013                                 2.240    1.837


                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  9 of  9

                                                                                
Station ID: 8771450                         PUBLICATION DATE:  12/09/2019
Name:       GALVESTON PIER 21, GALVESTON CHANNEL              
            TX
NOAA Chart: 11323                           Latitude:   29° 18.6' N (  29.31000)
USGS Quad:  GALVESTON                       Longitude:  94° 47.6' W ( -94.79331)


                             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.