U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
Datums Page                                                        Page  1 of  5

                                                                                
Station ID: 1631428                         PUBLICATION DATE:  09/28/2020
Name:       PAGO BAY, GUAM, PACIFIC OCEAN                     
            UNITED STATES OF AMERICA
NOAA Chart: 81048                           Latitude:   13° 25.7' N (  13.42833)
USGS Quad:  AGANA                           Longitude: 144° 47.8' E ( 144.79694)


To reach the tidal bench marks from the Guam International Airport, exit the
airport and turn right (north) on Highway 10A, follow it to the intersection
with Highway 16 and turn right, follow 16 to the intersection with Highway 10
and turn left, follow 10 to the turn off for Highway 32 and turn left.  Highway
32 will take you onto the campus of the University of Guam, stay on it past the
main campus buildings to a three way stop, continue straight, and down a steep
hill, to the Marine Laboratory building.  The tidal bench marks are located on
the University of Guam property.  The tide gauge instruments are located on the
east wall of room 104, in the lower level of the Marine Lab.


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


                 PRIMARY BENCH MARK STAMPING:  1428 B 2004
                         DESIGNATION:          163 1428 B TIDAL

MONUMENTATION:           Tidal Station disk                    VM#:        17608
AGENCY:                  National Ocean Service (NOS)          IDB PID#:  DH3105
SETTING CLASSIFICATION:  Beach limestone outcrop               OPUS PID:        
LATITUDE:   13° 25.7' N (  13.42769)          LONGITUDE: 144° 47.9' E ( 144.79886)


The primary bench mark is set in a limestone outcrop on the beach to the west of
the sea water intake sump for the University of Guam Marine Laboratory in
Mangilao, Guam, 11.03 m (36.2 ft) west of the SW corner of a cyclone fence
around the sump, 1.46 m (4.8 ft) south of the SW corner of the concrete sea wall
at the bottom of a concrete ramp between the Marine Lab and the beach, 0.61 m
(2.0 ft) east of the west face of limestone outcrop, and  1.37 m (4.5 ft) above
the apparent high water line.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  2 of  5

                                                                                
Station ID: 1631428                         PUBLICATION DATE:  09/28/2020
Name:       PAGO BAY, GUAM, PACIFIC OCEAN                     
            UNITED STATES OF AMERICA
NOAA Chart: 81048                           Latitude:   13° 25.7' N (  13.42833)
USGS Quad:  AGANA                           Longitude: 144° 47.8' E ( 144.79694)


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


                         BENCH MARK STAMPING:  1428 A 2004
                         DESIGNATION:          163 1428 A TIDAL

MONUMENTATION:           Tidal Station disk                    VM#:        17607
AGENCY:                  National Ocean Service (NOS)          IDB PID:         
SETTING CLASSIFICATION:  Bedrock beach                         OPUS PID:        
LATITUDE:   13° 25.0' N (  13.41675)          LONGITUDE: 144° 48.0' E ( 144.79917)


The bench mark is set in the bedrock beach to the east of the sea water intake
sump for the University of Guam Marine Laboratory in Mangilao, Guam, 16.30 m
(53.5 ft) east of the SE corner of a cyclone fence around the sump, 5.54 m (18.2
ft) west of the 15 m (49 ft) cliff bordering the shore,  2 m (6.5 ft) north of
the apparent high water line, and 0.6 m (2.0 ft) above the apparent high water
line.



                         BENCH MARK STAMPING:  1428 C 2004
                         DESIGNATION:          163 1428 C TIDAL

MONUMENTATION:           Tidal Station disk                    VM#:        17609
AGENCY:                  National Ocean Service (NOS)          IDB PID#:  DQ9577
SETTING CLASSIFICATION:  Concrete pad                          OPUS PID:        
LATITUDE:   13° 25.7' N (  13.42814)          LONGITUDE: 144° 47.9' E ( 144.79892)


The bench mark is set in the SW corner of a 4.9 m x 3.6 m (16 ft x 12 ft)
concrete pad in the lawn on the south side of the University of Guam Marine Lab
building in Mangilao, Guam,  5.73 m (18.8 ft)  south of the cinder block
retaining wall bordering the south side of the Marine Lab, 4.42 m (14.5 ft) 
west of the east side of the concrete pad, 3.29 m (10.8 ft)  east of the SE
corner of a stairway to the Marine Lab, and 0.15 m (0.5 ft) above the grade of
the lawn.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  3 of  5

                                                                                
Station ID: 1631428                         PUBLICATION DATE:  09/28/2020
Name:       PAGO BAY, GUAM, PACIFIC OCEAN                     
            UNITED STATES OF AMERICA
NOAA Chart: 81048                           Latitude:   13° 25.7' N (  13.42833)
USGS Quad:  AGANA                           Longitude: 144° 47.8' E ( 144.79694)


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


                         BENCH MARK STAMPING:  1428 D 2004
                         DESIGNATION:          163 1428 D TIDAL

MONUMENTATION:           Tidal Station disk                    VM#:        17610
AGENCY:                  National Ocean Service (NOS)          IDB PID#:  DQ9579
SETTING CLASSIFICATION:  Concrete utility vault                OPUS PID:        
LATITUDE:   13° 25.7' N (  13.42856)          LONGITUDE: 144° 47.9' E ( 144.79886)


The bench mark is set in the NW corner of a 1.37 m (4.5 ft) square concrete
utility vault on the north side of the University of Guam Marine Laboratory
building in Mangilao, Guam, 2.59 m (8.5 ft) north of the Marine Lab building,
1.74 m (5.7 ft) west of the west concrete base of a stairway hand rail, and 0.37
m (1.2 ft) east of the NE corner of a concrete block supporting an air
conditioning unit.



                         BENCH MARK STAMPING:  1215
                         DESIGNATION:          163 1428 GGN 1215

MONUMENTATION:           Survey disk                           VM#:        17613
AGENCY:                  Guam Geodetic Network                 IDB PID#:  DH2989
SETTING CLASSIFICATION:  Concrete monument                     OPUS PID:        
LATITUDE:   13° 25.7' N (  13.42894)          LONGITUDE: 144° 48.1' E ( 144.80128)


The bench mark is a disk set in the top of a concrete monument, set in the
ground on the south side of the road from the University of Guam campus to the
Marine Laboratory in Mangilao, Guam, located 250 m (820 ft) up the road from the
Marine Lab, just south of a speed bump, 12.16 m (39.9 ft) SW of the SW corner of
a concrete bus stop shelter, 14.10 m (46.3 ft) from a utility pole #LC-71-30,
3.54 m (11.6 ft) SE of a green telephone box marking buried cable, 1.52 m (5.0
ft) south of the south  edge of the road, and 0.3 m (0.9 ft) east of a bent 1 m
(3 ft) witness post with no sign attached.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  4 of  5

                                                                                
Station ID: 1631428                         PUBLICATION DATE:  09/28/2020
Name:       PAGO BAY, GUAM, PACIFIC OCEAN                     
            UNITED STATES OF AMERICA
NOAA Chart: 81048                           Latitude:   13° 25.7' N (  13.42833)
USGS Quad:  AGANA                           Longitude: 144° 47.8' E ( 144.79694)


                            T I D A L   D A T U M S 


Tidal datums at PAGO BAY, GUAM, PACIFIC OCEAN based on:

     LENGTH OF SERIES:      5 YEARS
     TIME PERIOD:           2/05-1/06, 2/09-1/11, 4/16-3/18
     TIDAL EPOCH:           1983-2001
     CONTROL TIDE STATION:  1630000 APRA HARBOR, GUAM, PACIFIC OCEAN


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

     HIGHEST OBSERVED WATER LEVEL (10/20/2004)         =  1.266
     MEAN HIGHER HIGH WATER                     MHHW   =  0.528
     MEAN HIGH WATER                            MHW    =  0.493
     MEAN TIDE LEVEL                            MTL    =  0.323
     MEAN SEA LEVEL                             MSL    =  0.310
     sland Vertical Datum                     Local =  0.240
     MEAN LOW WATER                             MLW    =  0.153
     MEAN LOWER LOW WATER                       MLLW   =  0.000
     LOWEST  OBSERVED WATER LEVEL (12/25/2004)         = -0.376



Bench Mark Elevation Information                In METERS above:

     Stamping or Designation                    MLLW        MHW

     1428 B 2004                                 2.576    2.083
     1428 A 2004                                 1.632    1.139
     1428 C 2004                                10.993   10.500
     1428 D 2004                                13.147   12.654
     1215                                       35.718   35.225


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

                                                                                
Station ID: 1631428                         PUBLICATION DATE:  09/28/2020
Name:       PAGO BAY, GUAM, PACIFIC OCEAN                     
            UNITED STATES OF AMERICA
NOAA Chart: 81048                           Latitude:   13° 25.7' N (  13.42833)
USGS Quad:  AGANA                           Longitude: 144° 47.8' E ( 144.79694)


                             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 any other fixed island datum.

This tide station location has a local island datum.  Island datums
are specific fixed geodetic datums whose elevation relationship 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/.