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

                                                                                
Station ID: 8723506                         PUBLICATION DATE:  11/13/2003
Name:       PUMPKIN KEY, CARD SOUND                           
            FL
NOAA Chart: 11463                           Latitude:   25° 19.5' N (  25.32500)
USGS Quad:  CARD SOUND                      Longitude:  80° 17.6' W ( -80.29330)


To reach the tidal bench marks from the interchange of the Florida Turnpike and
U.S. Highway 1 in Florida City, proceed north on U.S. Highway 1 for 1.0 km (0.6
mi) to Lucy Street, then east on Lucy Street (which becomes SW 328th Stree) for
14.2 km (8.8 mi) to the boat ramp at Biscayne National Park.  From there,
proceed by boat SSE on Biscayne Bay for 15.8 km (9.8 statute mi) to Pumpkin Key.
 The bench marks are on the north, east, and south shores of Pumpkin Key.  The
tide gage and staff were on the west end of the northernmost boat pier located
on the south end of the Key.


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


                 PRIMARY BENCH MARK STAMPING:  3506 D 1987
                         DESIGNATION:          872 3506 D

MONUMENTATION:           Tidal Station disk                    VM#:         5883
AGENCY:                  National Ocean Service (NOS)          IDB PID#:        
SETTING CLASSIFICATION:  Concrete sidewalk                     OPUS PID:        
LATITUDE:   25° 19.5' N (  25.32500)          LONGITUDE:  80° 17.6' W ( -80.29330)


The primary bench mark is a disk set in the sidewalk north of the north end of
the boat dock walkway located at the south end of Pumpkin Key, 20.24 m (66.4 ft)
WSW of a flag pole, 20.09 m (65.9 ft) WSW of bench mark 3506 E 1987, 11.67 m
(38.3 ft) south of the SW corner of a small lounge, 11.03 m (36.2 ft) SW of the
NW corner of a boat basin with a davit, and 0.43 m (1.4 ft) SE of the NW corner
of the dock walkway.

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

                                                                                
Station ID: 8723506                         PUBLICATION DATE:  11/13/2003
Name:       PUMPKIN KEY, CARD SOUND                           
            FL
NOAA Chart: 11463                           Latitude:   25° 19.5' N (  25.32500)
USGS Quad:  CARD SOUND                      Longitude:  80° 17.6' W ( -80.29330)


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


                         BENCH MARK STAMPING:  3506 E 1987
                         DESIGNATION:          872 3506 E

MONUMENTATION:           Tidal Station disk                    VM#:         5884
AGENCY:                  National Ocean Service (NOS)          IDB PID#:        
SETTING CLASSIFICATION:  Flagpole foundation                   OPUS PID:        
LATITUDE:   25° 19.5' N (  25.32500)          LONGITUDE:  80° 17.6' W ( -80.29330)


The bench mark is a disk set in the west end of the flagpole foundation at the
south end of Pumpkin Key, 11.22 m (36.8 ft) SW of the SE corner of the office,
10.49 m (34.4 ft) east of the NW corner of the boat basin with a davit, 0.27 m
(0.9 ft)  WNW of the flag pole, and 0.09 m (0.3 ft) below the surface of the
gravel around the flagpole base.



                         BENCH MARK STAMPING:  3506 F 1987
                         DESIGNATION:          872 3506 F

MONUMENTATION:           Tidal Station disk                    VM#:         5885
AGENCY:                  National Ocean Service (NOS)          IDB PID#:        
SETTING CLASSIFICATION:  Stainless steel rod                   OPUS PID:        
LATITUDE:   25° 19.5' N (  25.32500)          LONGITUDE:  80° 17.6' W ( -80.29330)


The bench mark is a disk at the SE end of Pumpkin Key near a golf cart road, 111
m (365 ft) NE along the golf cart road from the flagpole at the south end of the
key, 3.41 m (11.2 ft) SE of a 0.61 m (2.0 ft) diameter tree, 2.99 m (9.8 ft)
north of the north edge of the road, and 1.43 m (4.7 ft) WNW of a 0.3 m (1 ft)
diameter tree.  The bench mark is set 9 cm (0.3 ft) below ground level, crimped
to the top of a stainless steel rod driven 0.6 m (2 ft) to refusal, and encased
in a PVC pipe projecting 0.12 m (0.4 ft) above the ground.

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

                                                                                
Station ID: 8723506                         PUBLICATION DATE:  11/13/2003
Name:       PUMPKIN KEY, CARD SOUND                           
            FL
NOAA Chart: 11463                           Latitude:   25° 19.5' N (  25.32500)
USGS Quad:  CARD SOUND                      Longitude:  80° 17.6' W ( -80.29330)


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


                         BENCH MARK STAMPING:  3506 G 1987
                         DESIGNATION:          872 3506 G

MONUMENTATION:           Tidal Station disk                    VM#:         5886
AGENCY:                  National Ocean Service (NOS)          IDB PID#:        
SETTING CLASSIFICATION:  Coral rock outcrop                    OPUS PID:        
LATITUDE:   25° 19.5' N (  25.32500)          LONGITUDE:  80° 17.6' W ( -80.29330)


The bench mark is a disk set in a mound of concrete atop a coral rock outcrop
located at the east end of Pumpkin Key, 230 m (756 ft) along the east half of
the golf cart road from the flagpole at the south end of the key, 4.97 m (16.3
ft) WSW of a coral rock drop-off at the water's edge, 2.04 m (6.7 ft) WSW of an
0.46 m (1.5 ft) diameter twin-trunked tree, and 0.76 m (2.5 ft) ENE of the east
edge of the golf cart road.



                         BENCH MARK STAMPING:  3506 H 1987
                         DESIGNATION:          872 3506 H

MONUMENTATION:           Tidal Station disk                    VM#:         5887
AGENCY:                  National Ocean Service (NOS)          IDB PID#:        
SETTING CLASSIFICATION:  Coral rock outcrop                    OPUS PID:        
LATITUDE:   25° 19.5' N (  25.32500)          LONGITUDE:  80° 17.6' W ( -80.29330)


The bench mark is a disk set in a mound of concrete atop a coral rock outcrop
located at the north end of Pumpkin Key, west of the northernmost point of the
key, 413 m (1355 ft) along the east half of the golf cart road from the flagpole
at the south end of the key, 5.18 m (17.0 ft) NE of a small date palm tree, 2.38
m (7.8 ft) WSW of a coral rock drop-off at the water's edge, 1.83 m (6.0 ft)
north of a 0.24 m (0.8 ft) diameter tree, 2.35 m (7.7 ft) SE of another 0.24 m
(0.8 ft) diameter tree, and 1.46 m (4.8 ft) ENE of the east edge of the golf
cart road.

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

                                                                                
Station ID: 8723506                         PUBLICATION DATE:  11/13/2003
Name:       PUMPKIN KEY, CARD SOUND                           
            FL
NOAA Chart: 11463                           Latitude:   25° 19.5' N (  25.32500)
USGS Quad:  CARD SOUND                      Longitude:  80° 17.6' W ( -80.29330)


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


                         BENCH MARK STAMPING:  PRM KS 2325
                         DESIGNATION:          PRM KS 2325

MONUMENTATION:           Survey disk                           VM#:         5888
AGENCY:                  Private firm                          IDB PID#:        
SETTING CLASSIFICATION:  Concrete monument                     OPUS PID:        
LATITUDE:   25° 19.5' N (  25.32500)          LONGITUDE:  80° 17.6' W ( -80.29330)


The bench mark is a disk set in a square concrete monument located north of the
north end of the easternmost rock jetty on the south end of Pumpkin Key, 93.48 m
(306.7 ft) ESE of the flag pole, 11 m (35 ft) NNE of the north end of the
easternmost rock jetty, 2.35 m (7.7 ft) NNW of a 0.46 m (1.5 ft) diameter tree.

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

                                                                                
Station ID: 8723506                         PUBLICATION DATE:  11/13/2003
Name:       PUMPKIN KEY, CARD SOUND                           
            FL
NOAA Chart: 11463                           Latitude:   25° 19.5' N (  25.32500)
USGS Quad:  CARD SOUND                      Longitude:  80° 17.6' W ( -80.29330)


                            T I D A L   D A T U M S 


Tidal datums at PUMPKIN KEY, CARD SOUND based on:

     LENGTH OF SERIES:      2 MONTHS
     TIME PERIOD:           August 1987 - September 1987
     TIDAL EPOCH:           1983-2001
     CONTROL TIDE STATION:  8723970 VACA KEY, FLORIDA BAY


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

     MEAN HIGHER HIGH WATER                     MHHW   =  0.228
     MEAN HIGH WATER                            MHW    =  0.226
     MEAN TIDE LEVEL                            MTL    =  0.127
     MEAN SEA LEVEL                             MSL    =  0.111
     MEAN LOW WATER                             MLW    =  0.028
     MEAN LOWER LOW WATER                       MLLW   =  0.000

North American Vertical Datum (NAVD88)

Bench Mark Elevation Information                In METERS above:

     Stamping or Designation                    MLLW        MHW

     3506 D 1987                                 1.544    1.318
     3506 E 1987                                 1.889    1.663
     3506 F 1987                                 1.961    1.735
     3506 G 1987                                 0.830    0.604
     3506 H 1987                                 0.849    0.623
     PRM KS 2325                                 0.475    0.249


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

                                                                                
Station ID: 8723506                         PUBLICATION DATE:  11/13/2003
Name:       PUMPKIN KEY, CARD SOUND                           
            FL
NOAA Chart: 11463                           Latitude:   25° 19.5' N (  25.32500)
USGS Quad:  CARD SOUND                      Longitude:  80° 17.6' W ( -80.29330)


                             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.