U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
Datums Page                                                        Page  1 of 11

                                                                                
Station ID: 8775870                         PUBLICATION DATE:  09/27/2011
Name:       CORPUS CHRISTI, GULF OF MEXICO                    
            TX
NOAA Chart: 11307                           Latitude:   27° 34.8' N (  27.58000)
USGS Quad:  CRANE ISLAND SW                 Longitude:  97° 13.0' W ( -97.21670)


To reach the tidal bench marks from the intersection of County Park Road 53 and
County Park Road 22 on North Padre Island, proceed south on County Park Road 22
for 3.4 km (2.1 miles) to Padre Balli Park, turn left on the park entrance road
and proceed east for 0.6 km (0.4 miles), turn right on the beach road and follow
this road for 0.5 km (0.3 miles) to Bob Hall Pier.  The bench marks are at the
entrance to the park, on the pier, and in the park compound.  The tide gage is
located on a platform at the NW corner of the pier.


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


                 PRIMARY BENCH MARK STAMPING:  5870 A 1983
                         DESIGNATION:          877 5870 A TIDAL
                         ALIAS:                5870 A

MONUMENTATION:           Tidal Station disk                    VM#:          884
AGENCY:                  National Ocean Service (NOS)          IDB PID#:  AC8459
SETTING CLASSIFICATION:  Galvanized steel rod                  OPUS PID:        
LATITUDE:   27° 35.0' N (  27.58264)          LONGITUDE:  97° 13.2' W ( -97.22081)


The primary bench mark is a disk located NW of Bob Hall Pier,  7 m (23.0 ft)
north of a power pole with a light, 6.40 m (21.00 ft) south of the centerline of
the park access road leading to Bob Hall Pier, 6.00 m (19.68 ft) SE of the NE
corner of the pavement of the parking lot for Camping Area 1, and 3.00 m (9.84
ft) east of the north post of the entrance sign for Campsite 1.  The bench mark
is crimped to a galvanized steel rod driven 6.0 m (19.7 feet) encased in a
4-inch PVC pipe and concrete kickblock and marked with a witness post.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  2 of 11

                                                                                
Station ID: 8775870                         PUBLICATION DATE:  09/27/2011
Name:       CORPUS CHRISTI, GULF OF MEXICO                    
            TX
NOAA Chart: 11307                           Latitude:   27° 34.8' N (  27.58000)
USGS Quad:  CRANE ISLAND SW                 Longitude:  97° 13.0' W ( -97.21670)


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


                         BENCH MARK STAMPING:  HOLIDAY 1980
                         DESIGNATION:          HOLIDAY AZ MK
                         ALIAS:                Holiday 1980

MONUMENTATION:           Azimuth Mark disk                     VM#:          885
AGENCY:                  National Geodetic Survey (NGS)        IDB PID#:  AH1214
SETTING CLASSIFICATION:  Concrete monument                     OPUS PID#: AH1214
LATITUDE:   27° 35.2' N (  27.58675)          LONGITUDE:  97° 13.3' W ( -97.22125)


The bench mark is a disk set flush in the top of a concrete monument, located on
the south side of the entrance road to Padre Balli Park, 30.91 m (101.41 ft) WNW
of the centerline of Elliff Road, 11.31 m (37.1 ft) NE of Utility Pole 5, 4.91 m
(16.11 ft) SSW of the centerline of the entrance road, 3.51 m (11.52 ft) north
of a wooden pole with a metal pipe and shield marking the underground cable
route, and is in line with wooden posts and level with the surface of the
ground.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  3 of 11

                                                                                
Station ID: 8775870                         PUBLICATION DATE:  09/27/2011
Name:       CORPUS CHRISTI, GULF OF MEXICO                    
            TX
NOAA Chart: 11307                           Latitude:   27° 34.8' N (  27.58000)
USGS Quad:  CRANE ISLAND SW                 Longitude:  97° 13.0' W ( -97.21670)


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


                         BENCH MARK STAMPING:  5870 C 1983
                         DESIGNATION:          877 5870 C TIDAL
                         ALIAS:                5870 C

MONUMENTATION:           Tidal Station disk                    VM#:          886
AGENCY:                  National Ocean Service (NOS)          IDB PID#:  AC8456
SETTING CLASSIFICATION:  Galvanized steel rod                  OPUS PID:        
LATITUDE:   27° 35.2' N (  27.58628)          LONGITUDE:  97° 13.2' W ( -97.22014)


The bench mark is a disk located in the Padre Balli Park compound at the end of
the park entrance road, 16.1 m (52.8 ft) north of the centerline of the road
leading to the beach, 14.3 m (46.9 ft) east of the centerline of the divider
street between the park entrance and exit roads, and 3.0 m (9.8 feet) east of
Light Pole 440.  The bench mark is crimped to a galvanized steel rod driven 6.1
m (20.0 ft), into the ground and encased in a 4-inch PVC pipe and concrete
kickblock.  NOTE: rod may not fit inside the PVC pipe.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  4 of 11

                                                                                
Station ID: 8775870                         PUBLICATION DATE:  09/27/2011
Name:       CORPUS CHRISTI, GULF OF MEXICO                    
            TX
NOAA Chart: 11307                           Latitude:   27° 34.8' N (  27.58000)
USGS Quad:  CRANE ISLAND SW                 Longitude:  97° 13.0' W ( -97.21670)


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


                         BENCH MARK STAMPING:  5870 D 1983
                         DESIGNATION:          877 5870 D TIDAL
                         ALIAS:                5870 D 1983

MONUMENTATION:           Tidal Station disk                    VM#:          887
AGENCY:                  National Ocean Service (NOS)          IDB PID#:  AC8455
SETTING CLASSIFICATION:  Galvanized steel rod                  OPUS PID:        
LATITUDE:   27° 35.2' N (  27.58703)          LONGITUDE:  97° 13.3' W ( -97.22169)


The bench mark is a disk located on the Padre Balli Park compound in the median
between the park entrance and exit roads, 47.49 m (155.807 ft) south of the
centerline of the exit road, 16.00 m (52.49 ft) NNE of Utility Pole 4, and 5.61
m (18.4 ft) north of the centerline of the entrance road.  The bench mark is set
an top a galvanized steel rod driven 5.80 m (19.03 ft), and encased in a 4-inch
PVC pipe and concrete kickblock.  NOTE: rod may not fit inside the PVC pipe.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  5 of 11

                                                                                
Station ID: 8775870                         PUBLICATION DATE:  09/27/2011
Name:       CORPUS CHRISTI, GULF OF MEXICO                    
            TX
NOAA Chart: 11307                           Latitude:   27° 34.8' N (  27.58000)
USGS Quad:  CRANE ISLAND SW                 Longitude:  97° 13.0' W ( -97.21670)


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


                         BENCH MARK STAMPING:  5870 E 1983
                         DESIGNATION:          877 5870 E TIDAL
                         ALIAS:                5870 E 1983

MONUMENTATION:           Tidal Station disk                    VM#:          888
AGENCY:                  National Ocean Service (NOS)          IDB PID#:  AC8454
SETTING CLASSIFICATION:  Galvanized steel rod                  OPUS PID:        
LATITUDE:   27° 35.2' N (  27.58744)          LONGITUDE:  97° 13.4' W ( -97.22322)


The bench mark is a disk located near the intersection of park Road 22 and the
entrance road to Padre Balli Park, 14.30 m (46.92 ft) south of the centerline of
the entrance road, 10.00 m (32.81 ft) west of Utility Pole 38-1, and 1.31 m
(4.30 ft) east of the south corner of a brick wall surrounding a flower bed. 
The bench mark is crimped to a galvanized steel rod driven 6.10 m (20.01 ft),
and encased in a 4-inch PVC pipe and concrete kickblock.  NOTE: rod may not fit
inside the PVC pipe.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  6 of 11

                                                                                
Station ID: 8775870                         PUBLICATION DATE:  09/27/2011
Name:       CORPUS CHRISTI, GULF OF MEXICO                    
            TX
NOAA Chart: 11307                           Latitude:   27° 34.8' N (  27.58000)
USGS Quad:  CRANE ISLAND SW                 Longitude:  97° 13.0' W ( -97.21670)


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


                         BENCH MARK STAMPING:  5870 G 1985
                         DESIGNATION:          877 5870 G TIDAL
                         ALIAS:                5870 G

MONUMENTATION:           Tidal Station disk                    VM#:          890
AGENCY:                  National Ocean Service (NOS)          IDB PID#:  AC8460
SETTING CLASSIFICATION:  Pile cap                              OPUS PID:        
LATITUDE:   27° 34.9' N (  27.58215)          LONGITUDE:  97° 13.2' W ( -97.21933)


The bench mark is a disk set flush in the top of a concrete pier pile cap at the
inshore end of Bob Hall Pier, 6.90 m (22.64 ft) ESE of a chain link fence gate,
5.91 m (19.39 ft) SE of the SE corner of the restrooms on the pier, 4.60 m
(15.09 ft) south of the north face of the pier, and level with the surface of
the pier.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  7 of 11

                                                                                
Station ID: 8775870                         PUBLICATION DATE:  09/27/2011
Name:       CORPUS CHRISTI, GULF OF MEXICO                    
            TX
NOAA Chart: 11307                           Latitude:   27° 34.8' N (  27.58000)
USGS Quad:  CRANE ISLAND SW                 Longitude:  97° 13.0' W ( -97.21670)


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


                         BENCH MARK STAMPING:  5870 H 1985
                         DESIGNATION:          877 5870 H TIDAL
                         ALIAS:                5870 H 1985

MONUMENTATION:           Bench Mark disk                       VM#:          891
AGENCY:                  National Ocean Service (NOS)          IDB PID#:  AH1762
SETTING CLASSIFICATION:  Stainless steel rod                   OPUS PID#: AH1762
LATITUDE:   27° 35.3' N (  27.58817)          LONGITUDE:  97° 13.4' W ( -97.22286)


The bench mark is a disk located near the intersection of park road 22 and the
exit road from Padre Balli Park, 26 m (85.3 ft) south of Utility Pole 185, 14.60
m (47.90 ft) NNE of the centerline of the exit road, and 0.61 m (2.00 ft) SSE of
the NE corner of a concrete block wall.  The bench mark is set flush with the
ground, crimped to a galvanized steel rod driven 14.0 m (45.9 ft), and encased
in a 4-inch PVC pipe and concrete kickblock.  NOTE: rod may not fit inside the
PVC pipe.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  8 of 11

                                                                                
Station ID: 8775870                         PUBLICATION DATE:  09/27/2011
Name:       CORPUS CHRISTI, GULF OF MEXICO                    
            TX
NOAA Chart: 11307                           Latitude:   27° 34.8' N (  27.58000)
USGS Quad:  CRANE ISLAND SW                 Longitude:  97° 13.0' W ( -97.21670)


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


                         BENCH MARK STAMPING:  5870 J 1985
                         DESIGNATION:          877 5870 J TIDAL
                         ALIAS:                5870 J

MONUMENTATION:           Tidal Station disk                    VM#:          892
AGENCY:                  National Ocean Service (NOS)          IDB PID#:  AC8457
SETTING CLASSIFICATION:  Concrete foundation                   OPUS PID:        
LATITUDE:   27° 35.0' N (  27.58367)          LONGITUDE:  97° 13.2' W ( -97.22011)


The bench mark is a disk set flush in the concrete foundation for the Waste
Disposal Station in the Padre Balli Park campground, 19.51 m (64.01 ft) SSW of
the end of the pavement at the north end of the campground, 14.00 m (45.93 ft)
SSE of Power Pole 202, 8.20 m (26.9 ft) WNW of the edge of the pavement at the
east end of the campground, and 0.21 m (0.69 ft) above ground level.



                         BENCH MARK STAMPING:  5870 K 1985
                         DESIGNATION:          877 5870 K TIDAL
                         ALIAS:                5870 K

MONUMENTATION:           Tidal Station disk                    VM#:          893
AGENCY:                  National Ocean Service (NOS)          IDB PID#:  AC8461
SETTING CLASSIFICATION:  Pile cap                              OPUS PID:        
LATITUDE:   27° 34.9' N (  27.58094)          LONGITUDE:  97° 13.0' W ( -97.21647)


The bench mark is disk set flush in the top of a concrete pier pile cap at the
offshore end of Bob Hall Pier, 5.50 m (18.04 ft) WSW of the offshore end of the
pier, 3.81 m (12.5 ft) SSE of the north face of the pier, 1.31 m (4.3 ft) NNE of
the south face of the pier, and level with the surface of the pier.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  9 of 11

                                                                                
Station ID: 8775870                         PUBLICATION DATE:  09/27/2011
Name:       CORPUS CHRISTI, GULF OF MEXICO                    
            TX
NOAA Chart: 11307                           Latitude:   27° 34.8' N (  27.58000)
USGS Quad:  CRANE ISLAND SW                 Longitude:  97° 13.0' W ( -97.21670)


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


                         BENCH MARK STAMPING:  5870 L 2002
                         DESIGNATION:          877 5870 L
                         ALIAS:                5870 L

MONUMENTATION:           Bench Mark disk                       VM#:        17361
AGENCY:                  National Ocean Service (NOS)          IDB PID#:        
SETTING CLASSIFICATION:  Concrete picnic area                  OPUS PID:        
LATITUDE:   27° 35.1' N (  27.58431)          LONGITUDE:  97° 13.2' W ( -97.22006)


The bench mark is a disk set in a concrete slab at the picnic area just south of
the ranger station located NW of Bob Hall Pier, 37.3 m (122.4 ft) ESE of the
centerline of the road leading to the RV park, 22.2 m (72.8 ft) SSW of the edge
of an asphalt parking lot of the visitors center, 21.7 m (71.2 ft) NNW of the
electric pole with a transformer marked "01".  

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page 10 of 11

                                                                                
Station ID: 8775870                         PUBLICATION DATE:  09/27/2011
Name:       CORPUS CHRISTI, GULF OF MEXICO                    
            TX
NOAA Chart: 11307                           Latitude:   27° 34.8' N (  27.58000)
USGS Quad:  CRANE ISLAND SW                 Longitude:  97° 13.0' W ( -97.21670)


                            T I D A L   D A T U M S 


Tidal datums at CORPUS CHRISTI, GULF OF MEXICO based on:

     LENGTH OF SERIES:      16 YEARS
     TIME PERIOD:           January 1986 - December 2001
     TIDAL EPOCH:           1983-2001
     CONTROL TIDE STATION:  8779770 PORT ISABEL, LAGUNA MADRE


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

     HIGHEST OBSERVED WATER LEVEL (09/13/2008)         =  1.709
     MEAN HIGHER HIGH WATER                     MHHW   =  0.497
     MEAN HIGH WATER                            MHW    =  0.468
     MEAN SEA LEVEL                             MSL    =  0.282
     MEAN TIDE LEVEL                            MTL    =  0.268
     North American Vertical Datum              NAVD88 =  0.136
     MEAN LOW WATER                             MLW    =  0.068
     MEAN LOWER LOW WATER                       MLLW   =  0.000
     LOWEST  OBSERVED WATER LEVEL (02/28/1984)         = -0.836

North American Vertical Datum (NAVD88)

Bench Mark Elevation Information                In METERS above:

     Stamping or Designation                    MLLW        MHW

     5870 A 1983                                 2.745    2.277
     HOLIDAY 1980                                2.081    1.613
     5870 C 1983                                 1.907    1.439
     5870 D 1983                                 2.053    1.585
     5870 E 1983                                 1.871    1.403
     5870 G 1985                                 5.714    5.246
     5870 H 1985                                 2.110    1.642
     5870 J 1985                                 2.712    2.244
     5870 K 1985                                 5.086    4.618
     5870 L 2002                                 2.421    1.953


                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page 11 of 11

                                                                                
Station ID: 8775870                         PUBLICATION DATE:  09/27/2011
Name:       CORPUS CHRISTI, GULF OF MEXICO                    
            TX
NOAA Chart: 11307                           Latitude:   27° 34.8' N (  27.58000)
USGS Quad:  CRANE ISLAND SW                 Longitude:  97° 13.0' W ( -97.21670)


                             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.