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

                                                                                
Station ID: 8775241                         PUBLICATION DATE:  05/21/2021
Name:       ARANSAS, ARANSAS PASS                             
            TX
NOAA Chart: 11312                           Latitude:   27° 50.2' N (  27.83660)
USGS Quad:  PORT ARANSAS                    Longitude:  97°  2.3' W ( -97.03910)


From the intersection of Park Road 22 and TX HWY 361, head North on TX HWY 361
for 28.16 km (17.5 mi), then continue on S Alister St for 1.29 km (0.8 mi), then
turn right onto E Cotter Ave for 36.88 m (121 ft), then turn left onto Trout St
for 0.16 km (0.1 mi). From the Fisherman s Wharf in Port Aransas, a ride on the
Jetty Boat ferry can be chartered to cross the Port Aransas shipping channel to
San Jose Island. The station is a steel platform located on the South side of
the Northern jetty in Port Aransas.


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


                 PRIMARY BENCH MARK STAMPING:  877 5241 B 2016
                         DESIGNATION:          877 5241 B

MONUMENTATION:           Metal Rod                             VM#:        22255
AGENCY:                  Conrad Blucher Institute (CBI)        IDB PID:         
SETTING CLASSIFICATION:  Stainless steel rod                   OPUS PID#: BBGG79
LATITUDE:   27° 50.4' N (  27.84081)          LONGITUDE:  97°  2.8' W ( -97.04689)


The primary bench mark is located 94.5 m (310.0 ft) ESE from the center of the
jetty boat pier ramp, 79.1 m (259.5 ft) ESE from benchmark USACE 35, and30.8 m
(101.0 ft) NE from the center of the concrete jetty walkway, . The datum point
is the top of a stainless steel rod, driven 18.3 m (60 ft) to refusal and
encased in a 6 inch PVC pipe which extends .3 m (1 ft) above the ground with a
concrete kickblock with a magnet in the concrete.

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

                                                                                
Station ID: 8775241                         PUBLICATION DATE:  05/21/2021
Name:       ARANSAS, ARANSAS PASS                             
            TX
NOAA Chart: 11312                           Latitude:   27° 50.2' N (  27.83660)
USGS Quad:  PORT ARANSAS                    Longitude:  97°  2.3' W ( -97.03910)


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


                         BENCH MARK STAMPING:  65+.97
                         DESIGNATION:          USACE 1

MONUMENTATION:           Bench Mark disk                       VM#:        22249
AGENCY:                  US Corp of Engineers (USACE)          IDB PID:         
SETTING CLASSIFICATION:  Concrete jetty                        OPUS PID:        
LATITUDE:   27° 50.2' N (  27.83703)          LONGITUDE:  97°  2.4' W ( -97.03936)


The bench mark is a brass disk set in the top of the northern concrete jetty
located 348.98 m (1144.94 ft) ESE of USACE 3, 55.31 m (181.45 ft) NW of the tide
station.

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

                                                                                
Station ID: 8775241                         PUBLICATION DATE:  05/21/2021
Name:       ARANSAS, ARANSAS PASS                             
            TX
NOAA Chart: 11312                           Latitude:   27° 50.2' N (  27.83660)
USGS Quad:  PORT ARANSAS                    Longitude:  97°  2.3' W ( -97.03910)


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


                         BENCH MARK STAMPING:   
                         DESIGNATION:          USACE 2

MONUMENTATION:           Bench Mark disk                       VM#:        22250
AGENCY:                  US Corp of Engineers (USACE)          IDB PID:         
SETTING CLASSIFICATION:  Concrete Jetty                        OPUS PID:        
LATITUDE:   27° 50.3' N (  27.83761)          LONGITUDE:  97°  2.5' W ( -97.04111)


The bench mark is a brass disk set on the north side of the jetties and located
224.30 m (735.9 ft) NW of the station platform, 184.50 m (608.5 ft) NW of USACE
1, and 169.80 m (557.1 ft) SE of USACE 3.

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

                                                                                
Station ID: 8775241                         PUBLICATION DATE:  05/21/2021
Name:       ARANSAS, ARANSAS PASS                             
            TX
NOAA Chart: 11312                           Latitude:   27° 50.2' N (  27.83660)
USGS Quad:  PORT ARANSAS                    Longitude:  97°  2.3' W ( -97.03910)


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


                         BENCH MARK STAMPING:   
                         DESIGNATION:          USACE 4

MONUMENTATION:           Bench Mark disk                       VM#:        22252
AGENCY:                  US Corp of Engineers (USACE)          IDB PID:         
SETTING CLASSIFICATION:  Concrete jetty                        OPUS PID:        
LATITUDE:   27° 50.3' N (  27.83848)          LONGITUDE:  97°  2.6' W ( -97.04396)


The bench mark is a brass disk set on the north side of the jetties located
159.79 m (524.25 ft) ESE of USACE 5, 133.04 m (436.48 ft) WNW of USACE 3.

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

                                                                                
Station ID: 8775241                         PUBLICATION DATE:  05/21/2021
Name:       ARANSAS, ARANSAS PASS                             
            TX
NOAA Chart: 11312                           Latitude:   27° 50.2' N (  27.83660)
USGS Quad:  PORT ARANSAS                    Longitude:  97°  2.3' W ( -97.03910)


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


                         BENCH MARK STAMPING:  45
                         DESIGNATION:          USACE 5

MONUMENTATION:           Bench Mark disk                       VM#:        22253
AGENCY:                  US Corp of Engineers (USACE)          IDB PID:         
SETTING CLASSIFICATION:  Concrete jetty                        OPUS PID:        
LATITUDE:   27° 50.3' N (  27.83914)          LONGITUDE:  97°  2.7' W ( -97.04542)


The bench mark is a brass disk set on the north side of the jetties located
231.9 m (758.51 ft) SE of 877 5241 B, 159.79 m (524.25 ft) WNW of USACE 4.

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

                                                                                
Station ID: 8775241                         PUBLICATION DATE:  05/21/2021
Name:       ARANSAS, ARANSAS PASS                             
            TX
NOAA Chart: 11312                           Latitude:   27° 50.2' N (  27.83660)
USGS Quad:  PORT ARANSAS                    Longitude:  97°  2.3' W ( -97.03910)


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


                         BENCH MARK STAMPING:   
                         DESIGNATION:          USACE 35

MONUMENTATION:           Bench Mark disk                       VM#:        22254
AGENCY:                  US Corp of Engineers (USACE)          IDB PID:         
SETTING CLASSIFICATION:  Concrete jetty                        OPUS PID:        
LATITUDE:   27° 50.5' N (  27.84106)          LONGITUDE:  97°  2.9' W ( -97.04767)


The bench mark is a brass disk set on the north side of the jetties located
80.00 m (262.46 ft) WNW of 877 5241 B, 57.74 m (289.43 ft) SE of 877 5241 C.



                         BENCH MARK STAMPING:  877 5241 C 2016
                         DESIGNATION:          877 5241 C

MONUMENTATION:           Metal Rod                             VM#:        22256
AGENCY:                  Conrad Blucher Institute (CBI)        IDB PID:         
SETTING CLASSIFICATION:                                        OPUS PID#: BBGK17
LATITUDE:   27° 50.5' N (  27.84150)          LONGITUDE:  97°  2.9' W ( -97.04783)


The bench mark is located 149.40 m (490.2 ft) SE of 877 5241 D, 120.50 m (395.3
ft) NW from 877 5241 B, and 26.7 m (87.6 ft) NE from the center of the concrete
jetty. The datum point is the top of a stainless steel rod driven 23.2 m (76 ft)
to refusal, encased in a 6 inch PVC pipe which extends 0.3 m (1 ft) above the
ground with a concrete kickblock with a magnet in the concrete.

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

                                                                                
Station ID: 8775241                         PUBLICATION DATE:  05/21/2021
Name:       ARANSAS, ARANSAS PASS                             
            TX
NOAA Chart: 11312                           Latitude:   27° 50.2' N (  27.83660)
USGS Quad:  PORT ARANSAS                    Longitude:  97°  2.3' W ( -97.03910)


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


                         BENCH MARK STAMPING:  877 5241 D 2016
                         DESIGNATION:          877 5241 D

MONUMENTATION:           Metal Rod                             VM#:        22257
AGENCY:                  Conrad Blucher Institute (CBI)        IDB PID:         
SETTING CLASSIFICATION:  Stainless steel rod                   OPUS PID:        
LATITUDE:   27° 50.6' N (  27.84258)          LONGITUDE:  97°  2.9' W ( -97.04894)


The bench mark is located 211.20 m (692.9 ft) SE of 877 5241 E,  149.50 m (490.5
ft) NW of 877 5241 C, and 41.30 m (135.5 ft) NE of the center of the concrete
jetty walkway. The datum point is the top of a stainless steel rod driven 11.9 m
(39 ft) to refusal encased in a 6 inch PVC pipe which extends 0.3 m (1 ft) above
the ground with a concrete kickblock and with a magnet in the concrete.



                         BENCH MARK STAMPING:  877 5241 E 2016
                         DESIGNATION:          877 5241 E

MONUMENTATION:           Metal Rod                             VM#:        22258
AGENCY:                  Conrad Blucher Institute (CBI)        IDB PID:         
SETTING CLASSIFICATION:  Stainless steel rod                   OPUS PID:        
LATITUDE:   27° 50.6' N (  27.84381)          LONGITUDE:  97°  3.0' W ( -97.05039)


The bench mark is located 358.6 m (1176.5 ft) NW of 877 5241 C, 212.20 m (696.2
ft) NW of 877 5241 D, and 36.6 m (120.1 ft) NE from the center of the concrete
jetty walkway. The datum point is the top of a stainless steel rod driven 25.6 m
(84 ft) to refusal and encased in a 6 inch PVC pipe which extends 0.3 m (1 ft)
above the ground with concrete kickblock with a magnet in the concrete.

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

                                                                                
Station ID: 8775241                         PUBLICATION DATE:  05/21/2021
Name:       ARANSAS, ARANSAS PASS                             
            TX
NOAA Chart: 11312                           Latitude:   27° 50.2' N (  27.83660)
USGS Quad:  PORT ARANSAS                    Longitude:  97°  2.3' W ( -97.03910)


                            T I D A L   D A T U M S 


Tidal datums at ARANSAS, ARANSAS PASS based on:

     LENGTH OF SERIES:      3 YEARS
     TIME PERIOD:           October 2017 - September 2020
     TIDAL EPOCH:           1983-2001
     CONTROL TIDE STATION:  8775870 BOB HALL PIER, CORPUS CHRISTI


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

     HIGHEST OBSERVED WATER LEVEL (07/25/2020)         =  1.334
     MEAN HIGHER HIGH WATER                     MHHW   =  0.418
     MEAN HIGH WATER                            MHW    =  0.402
     MEAN SEA LEVEL                             MSL    =  0.255
     MEAN TIDE LEVEL                            MTL    =  0.233
     North American Vertical Datum              NAVD88 =  0.198
     MEAN LOW WATER                             MLW    =  0.065
     MEAN LOWER LOW WATER                       MLLW   =  0.000
     LOWEST  OBSERVED WATER LEVEL (01/20/2019)         = -0.442

North American Vertical Datum (NAVD88)

Bench Mark Elevation Information                In METERS above:

     Stamping or Designation                    MLLW        MHW

     877 5241 B 2016                             2.658    2.256
     65+.97                                      1.575    1.173
     USACE 2                                     1.488    1.086
     USACE 4                                     1.503    1.101
     45                                          1.717    1.315
     USACE 35                                    1.759    1.357
     877 5241 C 2016                             1.398    0.996
     877 5241 D 2016                             1.631    1.229
     877 5241 E 2016                             1.746    1.344


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

                                                                                
Station ID: 8775241                         PUBLICATION DATE:  05/21/2021
Name:       ARANSAS, ARANSAS PASS                             
            TX
NOAA Chart: 11312                           Latitude:   27° 50.2' N (  27.83660)
USGS Quad:  PORT ARANSAS                    Longitude:  97°  2.3' W ( -97.03910)


                             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.