U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
Datums Page                                                        Page  1 of  7

                                                                                
Station ID: 8723165                         PUBLICATION DATE:  05/07/2003
Name:       MIAMI, BISCAYNE BAY                               
            FL
NOAA Chart: 11468                           Latitude:   25° 46.7' N (  25.77830)
USGS Quad:  MIAMI                           Longitude:  80° 11.1' W ( -80.18500)


To reach the tidal bench marks from the intersection of Biscayne Boulevard and
Port Boulevard in Miami, proceed south on Biscayne Boulevard one block to the
entrance of Miamarina on the left.  The bench marks are located in the vicinity
of the marina and the west end of the Port Avenue bridge to the Port of Miami on
Dodge Island.  The tide gage and staff are located at the NW end of the
northernmost pier of the marina.


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


                 PRIMARY BENCH MARK STAMPING:  3165 A 1985
                         DESIGNATION:          872 3165 A

MONUMENTATION:           Tidal Station disk                    VM#:         5770
AGENCY:                  National Ocean Service (NOS)          IDB PID#:        
SETTING CLASSIFICATION:  Concrete wall                         OPUS PID:        
LATITUDE:   25° 46.7' N (  25.77830)          LONGITUDE:  80° 11.1' W ( -80.18500)


The primary bench mark is a disk set flush in the center of a 1 m (3 ft) wide
concrete wall around the parking lot, near the SE end of the northernmost pier
of Miamarina, 145 m (475 ft) NNE of the inside corner of the seawall at the
north side of the marina restaurant, 43 m (140 ft) west of the east face of the
concrete wall on the east side of Miamarina (on the Intracoastal Waterway), 30 m
(97 ft) north along the top of the concrete wall from the north end of the
Dockmaster building, 23 m (77 ft) south of the NE corner of the concrete marina
dock, 1 m (3 ft) above dock level, and 0.24 m (0.8 ft) above the level of the
parking lot.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  2 of  7

                                                                                
Station ID: 8723165                         PUBLICATION DATE:  05/07/2003
Name:       MIAMI, BISCAYNE BAY                               
            FL
NOAA Chart: 11468                           Latitude:   25° 46.7' N (  25.77830)
USGS Quad:  MIAMI                           Longitude:  80° 11.1' W ( -80.18500)


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


                         BENCH MARK STAMPING:  MH 16 1962
                         DESIGNATION:          MH 16
                         ALIAS:                872 3165 TIDAL USE

MONUMENTATION:           Survey disk                           VM#:         5767
AGENCY:                  US Army Corps of Engineers (USE)      IDB PID#:  AC2177
SETTING CLASSIFICATION:  Concrete bulkhead                     OPUS PID:        
LATITUDE:   25° 46.8' N (  25.78000)          LONGITUDE:  80° 11.1' W ( -80.18500)


The bench mark is a disk set flush in the top of a concrete bulkhead near its SE
corner on the north side of Miamarina, near the west end of the Port Boulevard
bridge leading to the Port of Miami, 10 m (33 ft) south of the south edge of the
bridge, 1.83 m (6.0 ft) west of the east end of the bulkhead, and 0.64 m (2.1
ft) north of the south face of the bulkhead.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  3 of  7

                                                                                
Station ID: 8723165                         PUBLICATION DATE:  05/07/2003
Name:       MIAMI, BISCAYNE BAY                               
            FL
NOAA Chart: 11468                           Latitude:   25° 46.7' N (  25.77830)
USGS Quad:  MIAMI                           Longitude:  80° 11.1' W ( -80.18500)


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


                         BENCH MARK STAMPING:  MH 16 RM 1 1962
                         DESIGNATION:          MH 16 RM 1
                         ALIAS:                872 3165 TIDAL USE

MONUMENTATION:           Survey disk                           VM#:         5768
AGENCY:                  US Army Corps of Engineers (USE)      IDB PID#:  AC2178
SETTING CLASSIFICATION:  Concrete bulkhead                     OPUS PID:        
LATITUDE:   25° 46.8' N (  25.78000)          LONGITUDE:  80° 11.1' W ( -80.18500)


The bench mark is a disk set flush in the top of a concrete bulkhead on the
north side of Miamarina, 17.37 m (57.0 ft) west of the east end of the bulkhead,
16 m (51 ft) west of bench mark MH 16 1962, 10 m (32 ft) south of the SW corner
of the Port Boulevard bridge, and 0.64 m (2.1 ft) north of the south face of the
bulkhead.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  4 of  7

                                                                                
Station ID: 8723165                         PUBLICATION DATE:  05/07/2003
Name:       MIAMI, BISCAYNE BAY                               
            FL
NOAA Chart: 11468                           Latitude:   25° 46.7' N (  25.77830)
USGS Quad:  MIAMI                           Longitude:  80° 11.1' W ( -80.18500)


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


                         BENCH MARK STAMPING:  MH 16 RM 2 1962
                         DESIGNATION:          MH 16 RM 2
                         ALIAS:                872 3165 TIDAL USE

MONUMENTATION:           Survey disk                           VM#:         5769
AGENCY:                  US Army Corps of Engineers (USE)      IDB PID#:  AC2179
SETTING CLASSIFICATION:  Concrete bulkhead                     OPUS PID:        
LATITUDE:   25° 46.8' N (  25.78000)          LONGITUDE:  80° 11.1' W ( -80.18500)


The bench mark is a disk set flush in the top of a concrete bulkhead near the
west end of the Port Boulevard bridge leading to the Port of Miami, 27 m (87 ft)
north of bench mark MH 16 1962, and 6 m (20 ft) south of the north end of the
bulkhead.



                         BENCH MARK STAMPING:  3165 B 1985
                         DESIGNATION:          872 3165 B

MONUMENTATION:           Tidal Station disk                    VM#:         5771
AGENCY:                  National Ocean Service (NOS)          IDB PID#:        
SETTING CLASSIFICATION:  Concrete sea wall                     OPUS PID:        
LATITUDE:   25° 46.7' N (  25.77830)          LONGITUDE:  80° 11.1' W ( -80.18500)


The bench mark is a disk set flush in the center of the top of the concrete
seawall cap which is parallel to Port Boulevard on the north side of Miamarina,
72 m (237 ft) west along the seawall from its east corner, 37 m (120 ft) east of
the inside west corner of the seawall at the NW corner of the marina, 11 m (37
ft) south of the centerline of the eastbound lane of Port Boulevard, and 2.96 m
(9.7 ft) south of the north edge of the asphalt sidewalk along the seawall.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  5 of  7

                                                                                
Station ID: 8723165                         PUBLICATION DATE:  05/07/2003
Name:       MIAMI, BISCAYNE BAY                               
            FL
NOAA Chart: 11468                           Latitude:   25° 46.7' N (  25.77830)
USGS Quad:  MIAMI                           Longitude:  80° 11.1' W ( -80.18500)


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


                         BENCH MARK STAMPING:  MIAMI EL 15.491
                         DESIGNATION:          15.491

MONUMENTATION:           Nail                                  VM#:         5772
AGENCY:                                                        IDB PID#:  AC2183
SETTING CLASSIFICATION:  Concrete wing wall                    OPUS PID:        
LATITUDE:   25° 46.8' N (  25.78000)          LONGITUDE:  80° 11.1' W ( -80.18500)


The bench mark is a nail with washer set in the SW wing wall of the Port
Boulevard bridge leading to the Port of Miami, 10.85 m (35.6 ft) north of bench
mark MH 16 RM 1 1962, 2.07 m (6.8 ft) south of the south curb of the bridge,
1.10 m (3.6 ft) NE of the SW end of the wingwall, and 0.30 m (1.0 ft) above the
sidewalk.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  6 of  7

                                                                                
Station ID: 8723165                         PUBLICATION DATE:  05/07/2003
Name:       MIAMI, BISCAYNE BAY                               
            FL
NOAA Chart: 11468                           Latitude:   25° 46.7' N (  25.77830)
USGS Quad:  MIAMI                           Longitude:  80° 11.1' W ( -80.18500)


                            T I D A L   D A T U M S 


Tidal datums at MIAMI, BISCAYNE BAY based on:

     LENGTH OF SERIES:      2 YEARS
     TIME PERIOD:           January 1985 - December 1986
     TIDAL EPOCH:           1983-2001
     CONTROL TIDE STATION:  8724580 KEY WEST


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

     HIGHEST OBSERVED WATER LEVEL (09/16/1985)         =  1.103
     MEAN HIGHER HIGH WATER                     MHHW   =  0.723
     MEAN HIGH WATER                            MHW    =  0.703
     North American Vertical Datum              NAVD88 =  0.643
     MEAN SEA LEVEL                             MSL    =  0.371
     MEAN TIDE LEVEL                            MTL    =  0.371
     MEAN LOW WATER                             MLW    =  0.040
     MEAN LOWER LOW WATER                       MLLW   =  0.000
     LOWEST  OBSERVED WATER LEVEL (04/07/1985)         = -0.345

North American Vertical Datum (NAVD88)

Bench Mark Elevation Information                In METERS above:

     Stamping or Designation                    MLLW        MHW

     3165 A 1985                                 2.154    1.451
     MH 16 1962                                  1.903    1.200
     MH 16 RM 1 1962                             1.891    1.188
     MH 16 RM 2 1962                             1.815    1.112
     3165 B 1985                                 1.899    1.196
     MIAMI EL 15.491                             4.804    4.101


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

                                                                                
Station ID: 8723165                         PUBLICATION DATE:  05/07/2003
Name:       MIAMI, BISCAYNE BAY                               
            FL
NOAA Chart: 11468                           Latitude:   25° 46.7' N (  25.77830)
USGS Quad:  MIAMI                           Longitude:  80° 11.1' W ( -80.18500)


                             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.