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

                                                                                
Station ID: 8726428                         PUBLICATION DATE:  06/16/2004
Name:       TIERRA VERDE                                      
            FL
NOAA Chart: 11414                           Latitude:   27° 41.3' N (  27.68830)
USGS Quad:  PASS-A-GRILLE BEACH             Longitude:  82° 43.1' W ( -82.71830)


To reach the tidal bench marks from the post office in St. Petersburg at the
intersection of 1st Avenue North and 4th Street, Travel west along 1st Avenue
north for 4.0 km (2.5 mi) to 34th Street (U.S. Route 19), travel south 5.8 km
(3.6 mi)  along U.S. Route 19, then 3.7 km (2.3 mi) west along the Pinellas
Bayway (State Route 693), then 2.3 km (1.45 mi) south along the Pinellas Bayway
across the Pinellas Bayway Bridge.  The gage was at the south side of the bridge
at the seawall at the end of 1st Avenue East, and the bench marks are along the
Pinellas Bayway and 1st Avenue East near the south end of the bridge.


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


                 PRIMARY BENCH MARK STAMPING:  6428 C 1976
                         DESIGNATION:          872 6428 C TIDAL

MONUMENTATION:           Tidal Station disk                    VM#:        12129
AGENCY:                  National Ocean Survey (NOS)           IDB PID#:  AG7403
SETTING CLASSIFICATION:  Copper-clad steel rod                 OPUS PID#: AG7403
LATITUDE:   27° 41.5' N (  27.69170)          LONGITUDE:  82° 43.2' W ( -82.72000)


The primary bench mark is a disk located 9 m (29 ft) east of the centerline of
the Pinellas Bayway southbound lane, 8.75 m (28.7 ft) WNW of the south end of
the first median south of the bridge over the main channel, and 8 m (27 ft)
south of the south end of the center island.  The bench mark is set on top of a
copper-clad steel rod driven 12.2 m (40 ft) to refusal, and encased in a PVC
pipe with concrete kickblock.

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

                                                                                
Station ID: 8726428                         PUBLICATION DATE:  06/16/2004
Name:       TIERRA VERDE                                      
            FL
NOAA Chart: 11414                           Latitude:   27° 41.3' N (  27.68830)
USGS Quad:  PASS-A-GRILLE BEACH             Longitude:  82° 43.1' W ( -82.71830)


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


                         BENCH MARK STAMPING:  6428 E 1976
                         DESIGNATION:          872 6428 E TIDAL

MONUMENTATION:           Tidal Station disk                    VM#:        12130
AGENCY:                  National Ocean Survey (NOS)           IDB PID#:  AG7404
SETTING CLASSIFICATION:  Concrete pad                          OPUS PID:        
LATITUDE:   27° 41.5' N (  27.69170)          LONGITUDE:  82° 43.2' W ( -82.72000)


The bench mark is a disk set in the NE corner of the concrete pad for the Tierra
Verde Shopping Center, 41.0 m (134.5 ft) SW of bench mark 6428 C 1976, 21 m (68
ft) west of the centerline of the southbound lane of the Pinellas Bayway, 13.4 m
(44 ft) north of the centerline of the westbound lane of Madonna Boulevard, and
0.61 m (2.0 ft) above the road level.

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

                                                                                
Station ID: 8726428                         PUBLICATION DATE:  06/16/2004
Name:       TIERRA VERDE                                      
            FL
NOAA Chart: 11414                           Latitude:   27° 41.3' N (  27.68830)
USGS Quad:  PASS-A-GRILLE BEACH             Longitude:  82° 43.1' W ( -82.71830)


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


                         BENCH MARK STAMPING:  N 17
                         DESIGNATION:          N 17

MONUMENTATION:           Survey disk                           VM#:        12131
AGENCY:                  Florida Highway Division (FLHD)       IDB PID#:  AG5266
SETTING CLASSIFICATION:  Concrete base                         OPUS PID:        
LATITUDE:   27° 41.5' N (  27.69170)          LONGITUDE:  82° 43.1' W ( -82.71830)


The bench mark is a disk set in the top of the concrete base for a metal
guardrail that borders the west edge of the walkway located on the east side of
a concrete highway drawbridge, 8 m (26 ft) north of the south end of the
concrete base, 1.34 m (4.4 ft) west of the east concrete guardrail on the
bridge, 0.15 m (0.5 ft) west of the metal guardrail, and 0.3 m (1 ft) above the
highway level. 



                         BENCH MARK STAMPING:  6428 F 1990
                         DESIGNATION:          872 6428 F TIDAL

MONUMENTATION:           Flange-encased Rod                    VM#:        12132
AGENCY:                  National Ocean Service (NOS)          IDB PID#:  AG9423
SETTING CLASSIFICATION:  Stainless steel rod                   OPUS PID:        
LATITUDE:   27° 41.5' N (  27.69170)          LONGITUDE:  82° 43.2' W ( -82.72000)


The bench mark is a flange-encased rod located at the Tierra Verde Marina, 30 m
(98 ft) NE of the NE corner of the dockmasters office, 5 m (16 ft) SW of a
wooden light pole, 1 m (2 ft) south of a black chain link fence, and 0.18 m (0.6
ft) SE of the carsonite witness post. The bench mark being the top of a
stainless steel rod driven 16.5 m (54 ft) to refusal encased in a NOS logo cap,
stamped 6428 F 1990, and  attached to a PVC pipe surrounded by concrete flush
with the ground. 

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

                                                                                
Station ID: 8726428                         PUBLICATION DATE:  06/16/2004
Name:       TIERRA VERDE                                      
            FL
NOAA Chart: 11414                           Latitude:   27° 41.3' N (  27.68830)
USGS Quad:  PASS-A-GRILLE BEACH             Longitude:  82° 43.1' W ( -82.71830)


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


                         BENCH MARK STAMPING:  6428 G 1990
                         DESIGNATION:          872 6428 G TIDAL

MONUMENTATION:           Flange-encased Rod                    VM#:        12133
AGENCY:                  National Ocean Service (NOS)          IDB PID#:  AG9425
SETTING CLASSIFICATION:  Stainless steel rod                   OPUS PID:        
LATITUDE:   27° 41.3' N (  27.68830)          LONGITUDE:  82° 43.3' W ( -82.72170)


The bench mark is located 218 m (715 ft) south of 6428 E 1976, 17 m (55 ft) SW
of power pole 135335, 14 m (45 ft) west of the centerline of St. Road 693, 5 m
(15 ft) east of a seawall, and 4 m (12 ft) south of the carsonite witness post.
The bench mark is the top of a stainless steel rod driven 16 m (54 ft) to
refusal encased in a NOS logo cap, stamped 6428 G 1990, and attached to a PVC
pipe surrounded by concrete flush with the ground.  

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

                                                                                
Station ID: 8726428                         PUBLICATION DATE:  06/16/2004
Name:       TIERRA VERDE                                      
            FL
NOAA Chart: 11414                           Latitude:   27° 41.3' N (  27.68830)
USGS Quad:  PASS-A-GRILLE BEACH             Longitude:  82° 43.1' W ( -82.71830)


                            T I D A L   D A T U M S 


Tidal datums at TIERRA VERDE based on:

     LENGTH OF SERIES:      5 MONTHS
     TIME PERIOD:           June 1990 - October 1990
     TIDAL EPOCH:           1983-2001
     CONTROL TIDE STATION:  8726520 ST. PETERSBURG, TAMPA BAY


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

     MEAN HIGHER HIGH WATER                     MHHW   =  0.659
     MEAN HIGH WATER                            MHW    =  0.577
     North American Vertical Datum              NAVD88 =  0.473
     MEAN SEA LEVEL                             MSL    =  0.347
     MEAN TIDE LEVEL                            MTL    =  0.340
     MEAN LOW WATER                             MLW    =  0.104
     MEAN LOWER LOW WATER                       MLLW   =  0.000

North American Vertical Datum (NAVD88)

Bench Mark Elevation Information                In METERS above:

     Stamping or Designation                    MLLW        MHW

     6428 C 1976                                 2.576    1.999
     6428 E 1976                                 2.337    1.760
     N 17                                        5.220    4.643
     6428 F 1990                                 2.528    1.951
     6428 G 1990                                 2.328    1.751


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

                                                                                
Station ID: 8726428                         PUBLICATION DATE:  06/16/2004
Name:       TIERRA VERDE                                      
            FL
NOAA Chart: 11414                           Latitude:   27° 41.3' N (  27.68830)
USGS Quad:  PASS-A-GRILLE BEACH             Longitude:  82° 43.1' W ( -82.71830)


                             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.