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

                                                   PUBLICATION DATE:  12/01/1986
Station ID: 8724154                                SUPERCEDED DATE:   04/21/2003
Name:       LITTLE PINE KEY SOUTH, BIG SPANISH CHANNEL        
            FLORIDA
NOAA Chart: 11445                                  Latitude:         24° 42.8' N
USGS Quad:  BIG PINE KEY                           Longitude:        81° 18.2' W


To reach the tidal bench marks by boat from Bogie Channel Bridge linking Doctors
Point on Big Pine Key to No Name Key, proceed ENE 3.2 Statute miles (5.1 km) to
the southernmost tip of Little Pine Key.  The bench marks are located on the
Key.  The tide gage and staff were located on the Government Wildlife Refuge
Wharf.


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


                 PRIMARY BENCH MARK STAMPING:  ENIP NO 1 1935

MONUMENTATION:           Survey Disk                               VM#:     6381
AGENCY:                                                            PID#:  AE4391
SETTING CLASSIFICATION:  Bedrock


The bench mark is set in bedrock 63.2 feet (19.3 m) ESE of Bench Mark ENIP 1935,
and 1.0 foot (0.3 m) SW of a witness post.



                         BENCH MARK STAMPING:  ENIP 1935

MONUMENTATION:           Survey Disk                               VM#:     6380
AGENCY:                                                            PID#:  AA1518
SETTING CLASSIFICATION:  Bedrock


The bench mark is on the south point of Little Pine Key in a clearing fringed on
the water side by mangroves, 1.6 feet (0.5 m) south of a witness post.



                         BENCH MARK STAMPING:  ENIP NO 2 1935

MONUMENTATION:           Survey Disk                               VM#:     6382
AGENCY:                                                            PID#:  AE4392
SETTING CLASSIFICATION:  Bedrock


The bench mark is set in bedrock in the southern part of the key, 133.0 feet
(40.5 m) WSW of Bench Mark ENIP NO 1 1935, 92.1 feet (28.1 m) SW of Bench Mark
ENIP 1935, and 1.8 foot (0.5 m) south of a witness post.

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

                                                   PUBLICATION DATE:  12/01/1986
Station ID: 8724154                                SUPERCEDED DATE:   04/21/2003
Name:       LITTLE PINE KEY SOUTH, BIG SPANISH CHANNEL        
            FLORIDA
NOAA Chart: 11445                                  Latitude:         24° 42.8' N
USGS Quad:  BIG PINE KEY                           Longitude:        81° 18.2' W


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


                         BENCH MARK STAMPING:  NO 4 1974

MONUMENTATION:           Survey Disk                               VM#:     6383
AGENCY:                                                            PID:         
SETTING CLASSIFICATION:  Copper-clad Steel Rod


The bench mark is on the southern tip of a small berm, 190 feet (58 m) SSW of
Bench Mark NO 5 1974, and 20 feet (6 m) from the inner mangrove fringe.  The
bench mark is crimped to the top of a copper-clad steel rod driven to refusal,
encased in a PVC pipe and concrete kickblock.



                         BENCH MARK STAMPING:  NO 5 1974

MONUMENTATION:           Survey Disk                               VM#:     6384
AGENCY:                                                            PID:         
SETTING CLASSIFICATION:  Copper-clad Steel Rod


The bench mark is 190 feet (58 m) NNE of Bench Mark NO 4 1974, 107.6 feet (32.8
m) SSW of Bench Mark 4154 F 1984, and 0.9 foot (0.3 m) SE of a witness post. 
The bench mark is crimped to the top of a copper-clad steel rod driven to
refusal, encased in a PVC pipe and concrete kickblock.



                         BENCH MARK STAMPING:  4154 F 1984

MONUMENTATION:           Survey Disk                               VM#:     6385
AGENCY:                                                            PID:         
SETTING CLASSIFICATION:  Stainless Steel Rod


The bench mark is set in a clearing, 220 feet (67 m) SW of Bench Mark ENIP NO 1
1935, 128.5 feet (39.2 m) SSW of Bench Mark ENIP NO 2 1935, and 0.7 foot (0.2 m)
SW of a witness post.  The bench mark is 1.7 feet (0.5 m) above ground, crimped
to the top of a stainless steel rod driven 18 feet (5 m) to refusal, encased in
a PVC pipe and concrete kickblock.

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

                                                   PUBLICATION DATE:  12/01/1986
Station ID: 8724154                                SUPERCEDED DATE:   04/21/2003
Name:       LITTLE PINE KEY SOUTH, BIG SPANISH CHANNEL        
            FLORIDA
NOAA Chart: 11445                                  Latitude:         24° 42.8' N
USGS Quad:  BIG PINE KEY                           Longitude:        81° 18.2' W


                            T I D A L   D A T U M S 


Tidal datums at LITTLE PINE KEY SOUTH, BIG SPANISH CHANNEL based on:

     LENGTH OF SERIES:      1 MONTH
     TIME PERIOD:           August 1974
     TIDAL EPOCH:           1960-1978
     CONTROL TIDE STATION:  8724211 Big Pine Key, Viaduct


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

     HIGHEST OBSERVED WATER LEVEL (08/18/1974)         =   1.67
     MEAN HIGHER HIGH WATER                     MHHW   =   1.14
     MEAN HIGH WATER                            MHW    =   0.87
     MEAN TIDE LEVEL                            MTL    =   0.53
     MEAN LOW WATER                             MLW    =   0.19
     MEAN LOWER LOW WATER                       MLLW   =   0.00
     LOWEST  OBSERVED WATER LEVEL (07/31/1974)         =  -0.25

North American Vertical Datum (NAVD88)

Bench Mark Elevation Information                In FEET above:

     Stamping or Designation                    MLLW        MHW

     ENIP NO 1 1935                              1.45      0.58
     ENIP 1935                                   1.72      0.85
     ENIP NO 2 1935                              1.78      0.91
     NO 4 1974                                   2.04      1.17
     NO 5 1974                                   1.89      1.02
     4154 F 1984                                 1.03      0.16


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

                                                   PUBLICATION DATE:  12/01/1986
Station ID: 8724154                                SUPERCEDED DATE:   04/21/2003
Name:       LITTLE PINE KEY SOUTH, BIG SPANISH CHANNEL        
            FLORIDA
NOAA Chart: 11445                                  Latitude:         24° 42.8' N
USGS Quad:  BIG PINE KEY                           Longitude:        81° 18.2' 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.