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

                                                                                
Station ID: 8720232                         PUBLICATION DATE:  03/25/2010
Name:       PABLO CREEK ENTRANCE                              
            FL
NOAA Chart: 11490                           Latitude:   30° 22.6' N (  30.37670)
USGS Quad:  MAYPORT                         Longitude:  81° 26.9' W ( -81.44830)


To reach the tidal bench marks from the Post Office in Mayport, proceed SW on
Highway A1A for approximately 1.4 km (0.9 mi) to a sand road leading west onto
the sand spit known as Little Jetties, then turn right and proceed west on the
sand road for 1.3 km (0.8 mi), then proceed south to the water's edge.  The
bench marks are along the sand spit.  The tide gage and staff were on a small
wooden offshore platform, 128 m (420 ft) SW of Bench Mark 0232 B 1977, and 76 m
(250 ft) NNE of the two side by side range markers.


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


                 PRIMARY BENCH MARK STAMPING:  0232 E 1982
                         DESIGNATION:          872 0232 E TIDAL

MONUMENTATION:           Tidal Station disk                    VM#:        10571
AGENCY:                  National Ocean Survey (NOS)           IDB PID#:  BC2417
SETTING CLASSIFICATION:  Stainless steel rod                   OPUS PID:        
LATITUDE:   30° 22.7' N (  30.37833)          LONGITUDE:  81° 26.9' W ( -81.44889)


The primary bench mark is a disk located 297.2 m (975.0 ft) west of a steel gate
on the west side of the western most parking area of the park, 80.5 m (264.0 ft)
west of bench mark 0232 D 1982, 28.7 m (94.3 ft) WSW of the intersection of the
main sand road and four track roads which converge, 7.3 m (24.0 ft) north of the
centerline of the main sand road, 6.3 m (20.8 ft) SW of the centerline of a
track road, 5.3 m (17.5 ft) east of a twin-trunked cedar tree with 25.4 cm (10.0
in) and 30.5 cm (12.0 in) trunks (the tree is 12.2 m (40.0 ft) east of another
twin-trunked cedar tree that is surrounded by 4 cabbage palm trees), 2.7 m (9.0
ft) south of the middle of 3 small cabbage palm trees ranging in height from 1.8
to 3.0 m (6.0 to 10.0 ft) (the distance between the outside trees is 2.4 m (8.0
ft)), 0.3 m (1.0 ft) north of a carsonite witness post and 0.3 m (1.0 ft) south
of a second carsonite witness post.  The bench mark is crimped to the top of a
stainless steel rod driven to refusal at a depth of 6.1 m (20.0 ft) encased in a
concrete kickblock flush with the ground.  NOTE:  A magnet was buried at the
south side of the mark.  

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

                                                                                
Station ID: 8720232                         PUBLICATION DATE:  03/25/2010
Name:       PABLO CREEK ENTRANCE                              
            FL
NOAA Chart: 11490                           Latitude:   30° 22.6' N (  30.37670)
USGS Quad:  MAYPORT                         Longitude:  81° 26.9' W ( -81.44830)


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


                         BENCH MARK STAMPING:  Z 324 1970
                         DESIGNATION:          Z 324

MONUMENTATION:           Bench Mark disk                       VM#:        10565
AGENCY:                  US Coast and Geodetic Survey
                         (USC&GS)                              IDB PID#:  BC0710
SETTING CLASSIFICATION:  Concrete monument                     OPUS PID:        
LATITUDE:   30° 22.9' N (  30.38167)          LONGITUDE:  81° 26.3' W ( -81.43833)


The bench mark is a disk set in the top of a concrete monument projecting 0.1 m
(0.4 ft) above the level of the ground, in the center of a triangle formed by
three 10.2 cm (4.0 in) steel pipes, 43.9 m (144.0 ft) south of a 76.2 cm (30.0
in) steel pipeline at the south shore of the St. Johns River, 31.7 m (104.0 ft)
ENE of the most northern 27.9 cm (11.0 in) diameter steel gate post at the
entrance to the Helen Cooper Floyd Little Jetties Park, 27.0 m (89.0 ft) west of
the centerline of Ocean Street (U.S. Highway A1A), 19.1 m (62.5 ft) north of the
centerline of the sand road, near the south side of six small cedar trees, 9.0 m
(31.0 ft) east of the centerline of a road leading NW to St. Johns River, 1.0 m
(2.0 ft) SE of a carsonite witness post, 1.0 m (2.0 ft) below the level of the
highway, and 0.1 m (0.3 ft) above ground level.

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

                                                                                
Station ID: 8720232                         PUBLICATION DATE:  03/25/2010
Name:       PABLO CREEK ENTRANCE                              
            FL
NOAA Chart: 11490                           Latitude:   30° 22.6' N (  30.37670)
USGS Quad:  MAYPORT                         Longitude:  81° 26.9' W ( -81.44830)


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


                         BENCH MARK STAMPING:  0232 D 1982
                         DESIGNATION:          872 0232 D TIDAL

MONUMENTATION:           Tidal Station disk                    VM#:        10570
AGENCY:                  National Ocean Survey (NOS)           IDB PID#:  BC2416
SETTING CLASSIFICATION:  Concrete monument                     OPUS PID:        
LATITUDE:   30° 22.7' N (  30.37833)          LONGITUDE:  81° 26.9' W ( -81.44806)


The bench mark is a disk set in the top of a concrete monument flush with the
gorund, 0.3 km (0.2 mi) west of bench mark 0232 C 1982, 161.2 m (529.0 ft) west
of a steel gate on the west side of the westernmost parking area of the park,
136.0 m (446.0 ft) east of bench mark 0232 E 1982, 22.1 m (72.5 ft) NE of an
45.7 cm (18.0 in) cabbage palm tree on the south side of the sand road, 11.2 m
(36.8 ft) west of the centerline of a track road leading north, 7.9 m (26.0 ft)
north of the centerline of the sand road, 9.2 m (30.3 ft) east of the centerline
of a track road leading NW, 5.9 m (19.2 ft) ESE of the center of two cabbage
palms 0.3 m (1.0 ft) north of a carsonite witness post and 0.3 m (1.0 ft) south
of a second carsonite witness post, and 9.0 cm (0.3 ft) above ground level. 
NOTE:  A magnet was buried on the south side of the mark.  

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

                                                                                
Station ID: 8720232                         PUBLICATION DATE:  03/25/2010
Name:       PABLO CREEK ENTRANCE                              
            FL
NOAA Chart: 11490                           Latitude:   30° 22.6' N (  30.37670)
USGS Quad:  MAYPORT                         Longitude:  81° 26.9' W ( -81.44830)


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


                         BENCH MARK STAMPING:  0232 F 2004
                         DESIGNATION:          872 0232 F

MONUMENTATION:           Bench Mark disk                       VM#:        19298
AGENCY:                  FL Department of Environmental
                         Protection (FLDEP)                    IDB PID#:  DL5752
SETTING CLASSIFICATION:  Concrete monument                     OPUS PID:        
LATITUDE:   30° 22.8' N (  30.37944)          LONGITUDE:  81° 26.6' W ( -81.44361)


The bench mark is a disk set in the top of a round concrete monument flush with
the ground, 23.0 m (75.3 ft) west of the southwest corner of a concrete sidewalk
leading to a fishing pier at the St Johns River, 23.0 m (75.0 ft) north of the
centerline of the sand road, 0.9 m (2.8 ft) north of a steel guardrail and 0.6 m
(2.1 ft) north of a carsonite witness post.  NOTE:  A magnet was buried at the
south side of the mark.  



                         BENCH MARK STAMPING:  0232 G 2004
                         DESIGNATION:          872 0232 G

MONUMENTATION:           Flange-encased Rod                    VM#:        19299
AGENCY:                  National Geodetic Survey (NGS)        IDB PID#:  DL5753
SETTING CLASSIFICATION:  Stainless steel rod                   OPUS PID:        
LATITUDE:   30° 22.7' N (  30.37861)          LONGITUDE:  81° 26.7' W ( -81.44472)


The bench mark is a flange-encased rod located 59.3 m (194.5 ft) SSW of a steel
tower for a green navigation marker, 6.7 m (22.0 ft) ESE of the east post of a
wetlands conservation area sign, 1.0 m (3.3 ft) south of a steel guardrail, and
0.5 m (1.8 ft) north of a carsonite witness post.  The datum point is recessed
0.1 m (0.4 ft) below the level of the NGS logo cap, being the top of a stainless
steel rod driven to refusal at a depth of 13.4 m (44.0 ft) encased in a 5-inch
NGS logo cap flush with the ground.  NOTE:  A magnet was buried on the south
side of the mark.

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

                                                                                
Station ID: 8720232                         PUBLICATION DATE:  03/25/2010
Name:       PABLO CREEK ENTRANCE                              
            FL
NOAA Chart: 11490                           Latitude:   30° 22.6' N (  30.37670)
USGS Quad:  MAYPORT                         Longitude:  81° 26.9' W ( -81.44830)


                            T I D A L   D A T U M S 


Tidal datums at PABLO CREEK ENTRANCE based on:

     LENGTH OF SERIES:      1 MONTH
     TIME PERIOD:           September 1977 - September 1977
     TIDAL EPOCH:           1983-2001
     CONTROL TIDE STATION:  8720220 MAYPORT (FERRY DEPOT), SAINT JOHNS RIVER


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

     MEAN HIGHER HIGH WATER                     MHHW   =  1.280
     MEAN HIGH WATER                            MHW    =  1.200
     North American Vertical Datum              NAVD88 =  0.763
     MEAN SEA LEVEL                             MSL    =  0.640
     MEAN TIDE LEVEL                            MTL    =  0.615
     MEAN LOW WATER                             MLW    =  0.030
     MEAN LOWER LOW WATER                       MLLW   =  0.000

North American Vertical Datum (NAVD88)

Bench Mark Elevation Information                In METERS above:

     Stamping or Designation                    MLLW        MHW

     0232 E 1982                                 2.791    1.591
     Z 324 1970                                  2.152    0.952
     0232 D 1982                                 2.451    1.251
     0232 F 2004                                 1.967    0.767
     0232 G 2004                                 1.972    0.772


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

                                                                                
Station ID: 8720232                         PUBLICATION DATE:  03/25/2010
Name:       PABLO CREEK ENTRANCE                              
            FL
NOAA Chart: 11490                           Latitude:   30° 22.6' N (  30.37670)
USGS Quad:  MAYPORT                         Longitude:  81° 26.9' W ( -81.44830)


                             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.