U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
Datums Page                                                        Page  1 of  6

                                                   PUBLICATION DATE:  08/07/1989
Station ID: 9759110                                SUPERCEDED DATE:   04/21/2003
Name:       MAGUEYES ISLAND, CARIBBEAN SEA                    
            PUERTO RICO
NOAA Chart: 25671                                  Latitude:         17° 58.3' N
USGS Quad:  PARGUERA                               Longitude:        67°  2.8' W


To reach the tidal bench marks from the intersection of Highway 116 and Highway
304, proceed south on Highway 304 for about 2 miles (3 km) to its end at the
village of La Parguera, turn east and continue for 0.5 mile (0.8 km) to a boat
dock.  From the boat dock take a small boat to Magueyes Island.  The bench marks
are on the Institute of Marine Biology, University of Puerto Rico campus.  The
tide gage and staff are on an L-shaped pier on the west side of the island.


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


                 PRIMARY BENCH MARK STAMPING:  TIDAL BM NO 1 CAMA UPR 1955 ELEV

MONUMENTATION:           Survey Disk                               VM#:     1398
AGENCY:                                                            PID:         
SETTING CLASSIFICATION:  Concrete Block


The bench mark is set flush in an 0.7-foot (0.2 m) square concrete block atop a
2-foot (1 m) high rock outcropping, 85.9 feet (26.2 m) SW of the south corner of
the main laboratory building, 55.9 feet (17.0 m) north of the east corner of
building #47-3-7-634, 44.5 feet (13.6 m) south of the south corner of the
laboratory building, and 33.0 feet (10.1 m) east of the east edge of a sidewalk
along the shore.



                         BENCH MARK STAMPING:  TIDAL BM NO 2 CAMA UPR 1955 ELEV

MONUMENTATION:           Survey Disk                               VM#:     1399
AGENCY:                                                            PID:         
SETTING CLASSIFICATION:  Concrete Block


The bench mark is set in a 0.7-foot (0.2 m) square concrete block between the
main laboratory building and the new laboratory building, 78.0 feet (23.8 m)
south of the main power and telephone pole, 27.8 feet (8.5 m) east of the SE
corner of the new laboratory building, 14.5 feet (4.4 m) SW of the NW corner of
the main laboratory building, and level with the ground.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  2 of  6

                                                   PUBLICATION DATE:  08/07/1989
Station ID: 9759110                                SUPERCEDED DATE:   04/21/2003
Name:       MAGUEYES ISLAND, CARIBBEAN SEA                    
            PUERTO RICO
NOAA Chart: 25671                                  Latitude:         17° 58.3' N
USGS Quad:  PARGUERA                               Longitude:        67°  2.8' W


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


                         BENCH MARK STAMPING:  TIDAL BM NO 3 CAMA UPR 1955 ELEV

MONUMENTATION:           Survey Disk                               VM#:     1400
AGENCY:                                                            PID:         
SETTING CLASSIFICATION:  Concrete Block


The bench mark is set in a 0.7-foot (0.2 m) square concrete block, 127 feet (39
m) SSE of the SE corner of building #47-3-7-557 (Physical Oceanography Office),
123 feet (37 m) south of the south corner of building #47-3-7-805, 11.5 feet
(3.5 m) NE of the center of a 2-foot (1 m) diameter triple trunk tree, and level
with the ground.



                         BENCH MARK STAMPING:  NO 5 1962

MONUMENTATION:           Survey Disk                               VM#:     1401
AGENCY:                                                            PID:         
SETTING CLASSIFICATION:  Concrete Block


The bench mark is set in a 0.7-foot (0.2 m) square concrete block, 45 feet  (14
m) east of the north corner of the laboratory building, and 35 feet (11 m) south
of the restrooms.



                         BENCH MARK STAMPING:  9110 A 1980

MONUMENTATION:           Survey Disk                               VM#:     1402
AGENCY:                                                            PID:         
SETTING CLASSIFICATION:  Bedrock


The bench mark is set in bedrock in front of building #47-3-7-557 (Physical
Oceanography Office), 37.5 feet (11.4 m) NE of the NW corner of the maintenance
office, 20 feet (6 m) NE of a concrete barbecue pit, 16.2 feet (4.9 m) south of
the west corner and 7.2 feet (2.2 m) NW of the south corner of building
#47-3-7-557, and level with the ground.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  3 of  6

                                                   PUBLICATION DATE:  08/07/1989
Station ID: 9759110                                SUPERCEDED DATE:   04/21/2003
Name:       MAGUEYES ISLAND, CARIBBEAN SEA                    
            PUERTO RICO
NOAA Chart: 25671                                  Latitude:         17° 58.3' N
USGS Quad:  PARGUERA                               Longitude:        67°  2.8' W


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


                         BENCH MARK STAMPING:  9110 B 1980

MONUMENTATION:           Survey Disk                               VM#:     1403
AGENCY:                                                            PID:         
SETTING CLASSIFICATION:  Bedrock


The bench mark is set in bedrock north of the L-shaped pier, 72.9 feet    (22.2
m) south of the power cable building, 36.8 feet (11.2 m) north of the NW corner
of the air compressor building, 43.3 feet (13.2 m) west of the SW corner of the
National Science Foundation building, and 8 feet (2 m) above pier walkway level.



                         BENCH MARK STAMPING:  9110 D 1980

MONUMENTATION:           Survey Disk                               VM#:     1404
AGENCY:                                                            PID:         
SETTING CLASSIFICATION:  Bedrock


The bench mark is set in bedrock along a pathway on the south side of the
island, 78.9 feet (24.0 m) south of the SW corner of the woodworking shop, 38.3
feet (11.7 m) north of the SW corner of building #47-3-7-612, and about 23 feet
(7 m) north of the shoreline.



                         BENCH MARK STAMPING:  9110 E 1980

MONUMENTATION:           Survey Disk                               VM#:     1405
AGENCY:                                                            PID:         
SETTING CLASSIFICATION:  Bedrock


The bench mark is set in bedrock along a pathway on the south side of the
island, 65.5 feet (20.0 m) SSE of the south side of building #47-3-7-612, and
about 20 feet (6 m) east of the shoreline.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  4 of  6

                                                   PUBLICATION DATE:  08/07/1989
Station ID: 9759110                                SUPERCEDED DATE:   04/21/2003
Name:       MAGUEYES ISLAND, CARIBBEAN SEA                    
            PUERTO RICO
NOAA Chart: 25671                                  Latitude:         17° 58.3' N
USGS Quad:  PARGUERA                               Longitude:        67°  2.8' W


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


                         BENCH MARK STAMPING:  9110 F 1982

MONUMENTATION:           Survey Disk                               VM#:     1406
AGENCY:                                                            PID:         
SETTING CLASSIFICATION:  Concrete Footing


The bench mark is set in the south side of a 2-foot (1 m) square concrete light
pole footing, 61.0 feet (18.6 m) SW of the SW corner of building #47-3-7-557
(Physical Oceanography Office), and 52.0 feet (15.8 m) west of the NW corner of
the maintenance building.



                         BENCH MARK STAMPING:  9110 G 1982

MONUMENTATION:           Survey Disk                               VM#:     1407
AGENCY:                                                            PID:         
SETTING CLASSIFICATION:  Bedrock


The bench mark is set in bedrock at the north end of the maintenance building,
32.2 feet (9.8 m) south of the SE corner of building #47-3-7-557 (Physical
Oceanography Office), and 13.1 feet (4.0 m) NE of the NW corner, and 7.7 feet
(2.3 m) north of the NE corner of the maintenance building.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  5 of  6

                                                   PUBLICATION DATE:  08/07/1989
Station ID: 9759110                                SUPERCEDED DATE:   04/21/2003
Name:       MAGUEYES ISLAND, CARIBBEAN SEA                    
            PUERTO RICO
NOAA Chart: 25671                                  Latitude:         17° 58.3' N
USGS Quad:  PARGUERA                               Longitude:        67°  2.8' W


                            T I D A L   D A T U M S 


Tidal datums at MAGUEYES ISLAND, CARIBBEAN SEA based on:

     LENGTH OF SERIES:      19 YEARS
     TIME PERIOD:           1960-1978
     TIDAL EPOCH:           1960-1978
     CONTROL TIDE STATION:   


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

     HIGHEST OBSERVED WATER LEVEL (08/31/1979)         =   2.23
     MEAN HIGHER HIGH WATER                     MHHW   =   0.70
     MEAN HIGH WATER                            MHW    =   0.69
     MEAN TIDE LEVEL                            MTL    =   0.35
     MEAN LOW WATER                             MLW    =   0.02
     MEAN LOWER LOW WATER                       MLLW   =   0.00
     LOWEST  OBSERVED WATER LEVEL (06/11/1968)         =  -0.80



Bench Mark Elevation Information                In FEET above:

     Stamping or Designation                    MLLW        MHW

     TIDAL BM NO 1 CAMA UPR 1955 ELEV           12.11     11.42
     TIDAL BM NO 2 CAMA UPR 1955 ELEV           22.92     22.23
     TIDAL BM NO 3 CAMA UPR 1955 ELEV           33.70     33.01
     NO 5 1962                                  20.67     19.98
     9110 A 1980                                10.73     10.04
     9110 B 1980                                10.53      9.84
     9110 D 1980                                 2.30      1.61
     9110 E 1980                                 3.16      2.47
     9110 F 1982                                 5.82      5.13
     9110 G 1982                                10.72     10.03


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

                                                   PUBLICATION DATE:  08/07/1989
Station ID: 9759110                                SUPERCEDED DATE:   04/21/2003
Name:       MAGUEYES ISLAND, CARIBBEAN SEA                    
            PUERTO RICO
NOAA Chart: 25671                                  Latitude:         17° 58.3' N
USGS Quad:  PARGUERA                               Longitude:        67°  2.8' 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 any other fixed island datum.

This tide station location has a defined island datum (PRVD02).  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 PRVD02 elevation is shown on the Elevations of Tidal Datums Table Referred
to MLLW only when two or more of the bench marks listed have PRVD02 elevations.
The PRVD02 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, PRVD02 bench mark elevations computed indirectly from the tidal
datums elevation table may differ slightly from PRVD02 elevations listed for
each bench mark in the NGS database.