U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
Datums Page                                                        Page  1 of  5

                                                                                
Station ID: 8727956                         PUBLICATION DATE:  05/20/2004
Name:       ECONFINA RIVER, INSIDE                            
            FL
NOAA Chart: 11405                           Latitude:   30°  3.2' N (  30.05330)
USGS Quad:  SNIPE ISLAND                    Longitude:  83° 54.6' W ( -83.91000)


To reach the tidal bench marks from the intersection of U.S. Highway 98 and U.S.
Highway 19 in Perry, proceed west on U.S. Highway 98 for 32.2 km (20.0 mi) to
the intersection of County Road C-14, then turn left and proceed south on County
Road C-14 for 8.7 km (5.4 mi) to a dirt road on the left, then turn and proceed
east on the dirt road for 1.3 km (0.8 mi) to a crossroads, then turn and proceed
south on the dirt road for 1.4 km (0.9 mi) to the last cottage at the road's
end.  The bench marks are located along the dirt road, and the tide gage and
staff were located on a catwalk in front of the cottage.


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


                 PRIMARY BENCH MARK STAMPING:  7956 A 1977
                         DESIGNATION:          872 7956 A TIDAL

MONUMENTATION:           Tidal Station disk                    VM#:         8259
AGENCY:                  Florida Department of Natural Resources
                         (FLDNR)                               IDB PID#:  BD2686
SETTING CLASSIFICATION:  Copper-clad steel rod                 OPUS PID:        
LATITUDE:   30°  3.3' N (  30.05500)          LONGITUDE:  83° 54.6' W ( -83.91000)


The primary bench mark is a disk located 13.29 m (43.6 ft) SW of the SW corner
of a cottage, 4.51 m (14.8 ft) east of the NE corner of the last cottage, 3.23 m
(10.6 ft) ESE of a live oak tree, and 0.06 m (0.2 ft) NE of a metal witness
post.  The bench mark is crimped to the top of a copper-clad steel rod driven
12.2 m (40 ft) to refusal, and encased in PVC pipe and concrete kickblock.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  2 of  5

                                                                                
Station ID: 8727956                         PUBLICATION DATE:  05/20/2004
Name:       ECONFINA RIVER, INSIDE                            
            FL
NOAA Chart: 11405                           Latitude:   30°  3.2' N (  30.05330)
USGS Quad:  SNIPE ISLAND                    Longitude:  83° 54.6' W ( -83.91000)


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


                         BENCH MARK STAMPING:  7956 B 1977
                         DESIGNATION:          872 7956 B TIDAL

MONUMENTATION:           Tidal Station disk                    VM#:         8260
AGENCY:                  Florida Department of Natural Resources
                         (FLDNR)                               IDB PID#:  BD2685
SETTING CLASSIFICATION:  Copper-clad steel rod                 OPUS PID:        
LATITUDE:   30°  3.3' N (  30.05500)          LONGITUDE:  83° 54.5' W ( -83.90830)


The bench mark is a disk located 73 m (240 ft) NE of bench mark 7956 A 1977,
10.85 m (35.6 ft) west of a live oak tree, 4 m (13 ft) SE of the centerline of
the road, 2.41 m (7.9 ft) NNW of another live oak tree, and 0.09 m (0.3 ft) NW
of a metal witness post.  The bench mark is crimped to the top of a copper-clad
steel rod driven 9.8 m (32 ft) to refusal, and encased in PVC pipe and concrete
kickblock.



                         BENCH MARK STAMPING:  7956 C 1977
                         DESIGNATION:          872 7956 C TIDAL

MONUMENTATION:           Tidal Station disk                    VM#:         8261
AGENCY:                  Florida Department of Natural Resources
                         (FLDNR)                               IDB PID#:  BD2684
SETTING CLASSIFICATION:  Copper-clad steel rod                 OPUS PID:        
LATITUDE:   30°  3.3' N (  30.05500)          LONGITUDE:  83° 54.5' W ( -83.90830)


The bench mark is a disk located 61 m (200 ft) NE of bench mark 7956 B 1977,
11.28 m (37.0 ft) east of a gate to a driveway, 4.24 m (13.9 ft) SE of the
centerline of the dirt road, and 0.12 m (0.4 ft) north of a metal witness post. 
The bench mark is crimped to the top of a copper-clad steel rod driven 9.8 m (32
ft) to refusal, and encased in a PVC pipe and concrete kickblock.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  3 of  5

                                                                                
Station ID: 8727956                         PUBLICATION DATE:  05/20/2004
Name:       ECONFINA RIVER, INSIDE                            
            FL
NOAA Chart: 11405                           Latitude:   30°  3.2' N (  30.05330)
USGS Quad:  SNIPE ISLAND                    Longitude:  83° 54.6' W ( -83.91000)


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


                         BENCH MARK STAMPING:  7956 D 1977
                         DESIGNATION:          872 7956 D TIDAL

MONUMENTATION:           Tidal Station disk                    VM#:         8262
AGENCY:                  Florida Department of Natural Resources
                         (FLDNR)                               IDB PID#:  BD2683
SETTING CLASSIFICATION:  Concrete monument                     OPUS PID:        
LATITUDE:   30°  3.3' N (  30.05500)          LONGITUDE:  83° 54.5' W ( -83.90830)


The bench mark is a disk set in the top of a concrete monument, 102 m (335 ft)
ENE of bench mark 7956 C 1977, 29.38 m (96.4 ft) ESE of a powerline pole, 10.03
m (32.9 ft) SSE of the centerline of the dirt road, 0.15 m (0.5 ft) west of a
metal witness post, and at ground level.



                         BENCH MARK STAMPING:  7956 E 1977
                         DESIGNATION:          872 7956 E TIDAL

MONUMENTATION:           Tidal Station disk                    VM#:         8263
AGENCY:                  Florida Department of Natural Resources
                         (FLDNR)                               IDB PID#:  BD2682
SETTING CLASSIFICATION:  Concrete monument                     OPUS PID:        
LATITUDE:   30°  3.3' N (  30.05500)          LONGITUDE:  83° 54.4' W ( -83.90670)


The bench mark is a disk set in the top of a concrete monument, 78 m (255 ft)
ENE of bench mark 7956 D 1977, 11.61 m (38.1 ft) WSW of a powerline pole, 11.37
m (37.3 ft) SSE of the centerline of a dirt road, 0.15 m (0.5 ft) NNW of a metal
witness post, and at ground level.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  4 of  5

                                                                                
Station ID: 8727956                         PUBLICATION DATE:  05/20/2004
Name:       ECONFINA RIVER, INSIDE                            
            FL
NOAA Chart: 11405                           Latitude:   30°  3.2' N (  30.05330)
USGS Quad:  SNIPE ISLAND                    Longitude:  83° 54.6' W ( -83.91000)


                            T I D A L   D A T U M S 


Tidal datums at ECONFINA RIVER, INSIDE based on:

     LENGTH OF SERIES:      2 MONTHS
     TIME PERIOD:           February 1977 - March 1977
     TIDAL EPOCH:           1983-2001
     CONTROL TIDE STATION:  8727520 CEDAR KEY, GULF OF MEXICO


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

     MEAN HIGHER HIGH WATER                     MHHW   =  0.972
     MEAN HIGH WATER                            MHW    =  0.895
     MEAN TIDE LEVEL                            MTL    =  0.517
     MEAN SEA LEVEL                             MSL    =  0.465
     North American Vertical Datum              NAVD88 =  0.390
     MEAN LOW WATER                             MLW    =  0.138
     MEAN LOWER LOW WATER                       MLLW   =  0.000

North American Vertical Datum (NAVD88)

Bench Mark Elevation Information                In METERS above:

     Stamping or Designation                    MLLW        MHW

     7956 A 1977                                 1.493    0.598
     7956 B 1977                                 1.587    0.692
     7956 C 1977                                 1.777    0.882
     7956 D 1977                                 1.283    0.388
     7956 E 1977                                 1.442    0.547


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

                                                                                
Station ID: 8727956                         PUBLICATION DATE:  05/20/2004
Name:       ECONFINA RIVER, INSIDE                            
            FL
NOAA Chart: 11405                           Latitude:   30°  3.2' N (  30.05330)
USGS Quad:  SNIPE ISLAND                    Longitude:  83° 54.6' W ( -83.91000)


                             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.