U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
Datums Page                                                        Page  1 of  4

                                                   PUBLICATION DATE:  09/01/1987
Station ID: 8723178                                SUPERCEDED DATE:   04/21/2003
Name:       MIAMI BEACH, GOVERNMENT CUT                       
            FLORIDA
NOAA Chart: 11468                                  Latitude:         25° 45.8' N
USGS Quad:  MIAMI                                  Longitude:        80°  7.8' W


To reach the tidal bench marks from the intersection of 5th Street and Collins
Avenue (State Highway A1A) in Miami Beach, proceed south on Collins Avenue for
0.5 mile (0.8 km) to Biscayne Street, then east on Biscayne Street for 0.1 mile
(0.2 km) to a gate leading onto the beach, then south along the beach to the
concrete fishing pier at the mouth of Government Cut.  The bench marks are
located in the vicinity of the pier and the city park, and the tide station is
located at the midpoint of the concrete fishing pier.


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


                 PRIMARY BENCH MARK STAMPING:  3178 A 1985

MONUMENTATION:           Survey Disk                               VM#:     5788
AGENCY:                                                            PID:         
SETTING CLASSIFICATION:  Concrete Pier


The bench mark is set flush in the top of a concrete pile cap at the west end of
the concrete fishing pier on Government Cut, 447 feet (136 m) WNW of Bench Mark
MH-27 1978, 27.5 feet (8.4 m) NNE of the SW corner of the concrete pier, 21 feet
(6 m) SSW of the center line of the asphalt promenade, 1 foot (0.3 m) WNW of the
west end of the concrete pier, and 0.5 foot (0.2 m) below the level of the pier.



                         BENCH MARK STAMPING:  R 74 1974

MONUMENTATION:           Survey Disk                               VM#:     5786
AGENCY:                                                            PID:         
SETTING CLASSIFICATION:  Concrete Bulkhead


The bench mark is set flush in the top of the SW corner of a concrete bulkhead
running NE/SW along the beach,  SSE of the SE corner of the pilots building, 1.7
feet (0.5 m) NE of the SW edge of the bulkhead with a chain link fence adjacent
to it, and 1.6 feet (0.5 m) NW of the SE edge of the bulkhead.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  2 of  4

                                                   PUBLICATION DATE:  09/01/1987
Station ID: 8723178                                SUPERCEDED DATE:   04/21/2003
Name:       MIAMI BEACH, GOVERNMENT CUT                       
            FLORIDA
NOAA Chart: 11468                                  Latitude:         25° 45.8' N
USGS Quad:  MIAMI                                  Longitude:        80°  7.8' W


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


                         BENCH MARK STAMPING:  MH-27 1978 JAX FLA

MONUMENTATION:           Survey Disk                               VM#:     5787
AGENCY:                                                            PID:         
SETTING CLASSIFICATION:  Concrete Pier


The bench mark is set flush in the concrete pier deck at the SE end of the
concrete pier along the north shore of Government Cut, 31.2 feet (9.5 m) SW of
the NE edge of the deck, 5.0 feet (1.5 m) NW of the SE edge of the deck, 5.0
feet (1.5 m) NE of the SW edge of the deck.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  3 of  4

                                                   PUBLICATION DATE:  09/01/1987
Station ID: 8723178                                SUPERCEDED DATE:   04/21/2003
Name:       MIAMI BEACH, GOVERNMENT CUT                       
            FLORIDA
NOAA Chart: 11468                                  Latitude:         25° 45.8' N
USGS Quad:  MIAMI                                  Longitude:        80°  7.8' W


                            T I D A L   D A T U M S 


Tidal datums at MIAMI BEACH, GOVERNMENT CUT based on:

     LENGTH OF SERIES:      11 MONTHS
     TIME PERIOD:           FEBRUARY-DECEMBER 1985
     TIDAL EPOCH:           1960-1978
     CONTROL TIDE STATION:  8723080 HAULOVER PIER


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

     HIGHEST OBSERVED WATER LEVEL (09/16/1985)         =   3.87
     MEAN HIGHER HIGH WATER                     MHHW   =   2.53
     MEAN HIGH WATER                            MHW    =   2.48
     MEAN TIDE LEVEL                            MTL    =   1.32
     MEAN LOW WATER                             MLW    =   0.16
     MEAN LOWER LOW WATER                       MLLW   =   0.00
     LOWEST  OBSERVED WATER LEVEL (04/07/1985)         =  -1.20



Bench Mark Elevation Information                In FEET above:

     Stamping or Designation                    MLLW        MHW

     3178 A 1985                                12.27      9.79
     R 74 1974                                  10.73      8.25
     MH-27 1978 JAX FLA                         12.92     10.44


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

                                                   PUBLICATION DATE:  09/01/1987
Station ID: 8723178                                SUPERCEDED DATE:   04/21/2003
Name:       MIAMI BEACH, GOVERNMENT CUT                       
            FLORIDA
NOAA Chart: 11468                                  Latitude:         25° 45.8' N
USGS Quad:  MIAMI                                  Longitude:        80°  7.8' 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 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 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.