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

                                                                                
Station ID: 8724967                         PUBLICATION DATE:  05/06/2003
Name:       MARCO ISLAND, CAXAMBAS PASS                       
            FL
NOAA Chart: 11429                           Latitude:   25° 54.5' N (  25.90830)
USGS Quad:  MARCO ISLAND                    Longitude:  81° 43.7' W ( -81.72830)


To reach the tidal bench marks from the intersection of State Road 92 and State
Road 951 (Collier Boulevard) on Marco Island, proceed south on Collier Boulevard
for 2.9 km (1.8 mi) to the Deltona Corporation property.  The bench marks are
located along Swallow Avenue, Collier Boulevard, and on Deltona Corporation
property.  The tide gage and staff were located on the seawall south of bench
mark CAXAMBAS 1959 1975.


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


                 PRIMARY BENCH MARK STAMPING:  CAXAMBAS 1959 1975
                         DESIGNATION:          872 4967 CAXAMBAS RESET

MONUMENTATION:           Triangulation Station disk            VM#:         9730
AGENCY:                  National Geodetic Survey (NGS)        IDB PID#:  AC3260
SETTING CLASSIFICATION:  Concrete filled terra-cotta pipe      OPUS PID:        
LATITUDE:   25° 54.6' N (  25.91000)          LONGITUDE:  81° 43.7' W ( -81.72830)


The primary bench mark is a disk set in the top of a concrete filled terra-cotta
pipe just south of the pump house on Deltona Corporation Property, west of where
a paved private road becomes a dirt road on the Deltona Corporation property,
114 (375 ft) SE of the north corner of the bulkhead, 91 m (300 ft) NNE of the NE
corner of an abandoned industrial building #12912, 31 m (102 ft) NW of utility
pole T-11355, 17 m (55 ft) south of a dilapidated chain link fence, 1.22 m (4.0
ft) west of a metal witness post, 0.15 m (0.5 ft) east of another metal witness
post, and 0.21 m (0.7 ft) above ground level.

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

                                                                                
Station ID: 8724967                         PUBLICATION DATE:  05/06/2003
Name:       MARCO ISLAND, CAXAMBAS PASS                       
            FL
NOAA Chart: 11429                           Latitude:   25° 54.5' N (  25.90830)
USGS Quad:  MARCO ISLAND                    Longitude:  81° 43.7' W ( -81.72830)


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


                         BENCH MARK STAMPING:  NO 7 1976
                         DESIGNATION:          872 4967 TIDAL 7

MONUMENTATION:           Tidal Station disk                    VM#:         9735
AGENCY:                  National Ocean Survey (NOS)           IDB PID#:  AC3261
SETTING CLASSIFICATION:  Copper-clad steel rod                 OPUS PID:        
LATITUDE:   25° 54.6' N (  25.91000)          LONGITUDE:  81° 43.5' W ( -81.72500)


The bench mark is a disk located on a paved road leading south to an abandoned
warehouses, 20 m (66 ft) west of the centerline of a paved road leading south
from Collier Boulevard, 15 m (48 ft) NE of the east entrance to the Deltona
Corporation property, and 0.40 m (1.3 ft) south of a power pole with a witness
sign.  The bench mark is set at ground level, crimped to the top of a
copper-clad steel rod driven 12 m (40 ft) to refusal, and encased in a 4-inch
PVC pipe and concrete kickblock.



                         BENCH MARK STAMPING:  4967 A 1979
                         DESIGNATION:          872 4967 A TIDAL

MONUMENTATION:           Tidal Station disk                    VM#:         9736
AGENCY:                  National Ocean Survey (NOS)           IDB PID#:  AC3262
SETTING CLASSIFICATION:  Copper-clad steel rod                 OPUS PID:        
LATITUDE:   25° 54.6' N (  25.91000)          LONGITUDE:  81° 43.5' W ( -81.72500)


The bench mark is a disk located south on Collier Boulevard on Deltona
Corporation property, 96 m (315 ft) north of bench mark NO 7 1976, 23 m (74.0
ft) WSW of the centerpoint of the first crossover after the bend in Collier
Boulevard, 1.07 m (3.5 ft) SE of a green UTS telephone junction box #1100-1, and
0.30 m (1.0 ft) east of power pole #T2826 with a witness sign attached.  The
bench mark is set 3 cm (0.1 ft) above the ground, crimped to the top of a
copper-clad steel rod driven 14.6 m (48 ft) to refusal, and encased in a pipe.

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

                                                                                
Station ID: 8724967                         PUBLICATION DATE:  05/06/2003
Name:       MARCO ISLAND, CAXAMBAS PASS                       
            FL
NOAA Chart: 11429                           Latitude:   25° 54.5' N (  25.90830)
USGS Quad:  MARCO ISLAND                    Longitude:  81° 43.7' W ( -81.72830)


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


                         BENCH MARK STAMPING:  4967 B 1979
                         DESIGNATION:          872 4967 B TIDAL

MONUMENTATION:           Tidal Station disk                    VM#:         9737
AGENCY:                  National Ocean Survey (NOS)           IDB PID#:  AC3263
SETTING CLASSIFICATION:  Copper-clad steel rod                 OPUS PID#: AC3263
LATITUDE:   25° 54.7' N (  25.91170)          LONGITUDE:  81° 43.5' W ( -81.72500)


The bench mark is a disk located south on Collier Boulevard on the Deltona
Corporation property, 50 m (164 ft) NE of bench mark 4967 A 1979, 25.45 m (83.5
ft) SSE of the SE corner of Island Club Condominium (a yellow 3-story stucco
building), 9.75 m (32.0 ft) north of the centerline of Collier Boulevard
(northbound land), 6.19 m (20.3 ft) SE of the SE corner of the parking lot, 0.76
m (2.5 ft) east of a concrete power pole, and 1 m (3 ft) east of a witness post.
 The bench mark is set at ground level, crimped to the top of a copper-clad
steel rod driven 14.6 m (48 ft) to refusal, and encased in a pipe.



                         BENCH MARK STAMPING:  4967 C 1979
                         DESIGNATION:          872 4967 C TIDAL

MONUMENTATION:           Tidal Station disk                    VM#:        10543
AGENCY:                  National Ocean Survey (NOS)           IDB PID#:  AC3264
SETTING CLASSIFICATION:  Copper-clad steel rod                 OPUS PID:        
LATITUDE:   25° 54.8' N (  25.91330)          LONGITUDE:  81° 43.5' W ( -81.72500)


The bench mark is a disk located east on Swallow Avenue, 81 m (266 ft) north of
bench mark 4967 B 1979, 24.66 m (80.9 ft) NNE of the NE corner of Island Club
Condominium (a yellow 3-story stucco building), 12.16 m (39.9 ft) south of the
centerline of Swallow Avenue, 0.30 m (1.0 ft) west of a concrete power pole with
a witness sign, and 0.24 m (0.8 ft) south of the south edge of the sidewalk. 
The bench mark is set at ground level, crimped to the top of a copper-clad steel
rod driven 19.5 m (64 ft) to refusal, and encased in a pipe.

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

                                                                                
Station ID: 8724967                         PUBLICATION DATE:  05/06/2003
Name:       MARCO ISLAND, CAXAMBAS PASS                       
            FL
NOAA Chart: 11429                           Latitude:   25° 54.5' N (  25.90830)
USGS Quad:  MARCO ISLAND                    Longitude:  81° 43.7' W ( -81.72830)


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


                         BENCH MARK STAMPING:  CAXAMBAS 2 1979
                         DESIGNATION:          872 4967 CAXAMBAS 2

MONUMENTATION:           Triangulation Station disk            VM#:        16796
AGENCY:                  National Geodetic Survey (NGS)        IDB PID#:  AC3265
SETTING CLASSIFICATION:  Concrete monument                     OPUS PID:        
LATITUDE:   25° 54.7' N (  25.91170)          LONGITUDE:  81° 43.6' W ( -81.72670)


The bench mark is a disk set in the top of a concrete monument in the median of
lane, 14.87 m (48.8 ft) NE of the bench mark Caxambas 2 NO 6 1979, 6.13 m (20.1
ft) SW of the centerline of the northbound lane of Collier Boulevard, 6 m (20
ft) NE of the centerline of the southbound lane of Collier Boulevard, and 2.29 m
(7.5 ft) south of a witness point.



                         BENCH MARK STAMPING:  CAXAMBAS 2 NO 6 1979
                         DESIGNATION:          872 4967 CAXAMBAS 2 RM 6

MONUMENTATION:           Reference Mark disk                   VM#:        16797
AGENCY:                  National Geodetic Survey (NGS)        IDB PID#:  AC3266
SETTING CLASSIFICATION:  Concrete monument                     OPUS PID:        
LATITUDE:   25° 54.7' N (  25.91170)          LONGITUDE:  81° 43.5' W ( -81.72500)


The bench mark is a disk set in the top of a concrete monument located south on
Collier Boulevard, 14.87 m (48.8 ft) SW of bench mark CAXAMBAS 2 1979, 10.15 m
(33.3 ft) NW of an Australian pine tree, and 8.78 m (28.8 ft) SW of the
centerline of the southbound lane of Collier Boulevard.

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

                                                                                
Station ID: 8724967                         PUBLICATION DATE:  05/06/2003
Name:       MARCO ISLAND, CAXAMBAS PASS                       
            FL
NOAA Chart: 11429                           Latitude:   25° 54.5' N (  25.90830)
USGS Quad:  MARCO ISLAND                    Longitude:  81° 43.7' W ( -81.72830)


                            T I D A L   D A T U M S 


Tidal datums at MARCO ISLAND, CAXAMBAS PASS based on:

     LENGTH OF SERIES:      36 MONTHS
     TIME PERIOD:           February 1976 - January 1979
     TIDAL EPOCH:           1983-2001
     CONTROL TIDE STATION:  8725110 NAPLES, GULF OF MEXICO


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

     HIGHEST OBSERVED WATER LEVEL (06/02/1977)         =  1.357
     MEAN HIGHER HIGH WATER                     MHHW   =  0.932
     MEAN HIGH WATER                            MHW    =  0.856
     North American Vertical Datum              NAVD88 =  0.721
     MEAN TIDE LEVEL                            MTL    =  0.519
     MEAN SEA LEVEL                             MSL    =  0.513
     MEAN LOW WATER                             MLW    =  0.181
     MEAN LOWER LOW WATER                       MLLW   =  0.000
     LOWEST  OBSERVED WATER LEVEL (01/18/1976)         = -0.493

North American Vertical Datum (NAVD88)

Bench Mark Elevation Information                In METERS above:

     Stamping or Designation                    MLLW        MHW

     CAXAMBAS 1959 1975                          2.000    1.144
     NO 7 1976                                   1.932    1.076
     4967 A 1979                                 2.316    1.460
     4967 B 1979                                 2.325    1.469
     4967 C 1979                                 2.064    1.208
     CAXAMBAS 2 1979                             2.185    1.329
     CAXAMBAS 2 NO 6 1979                        2.073    1.217


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

                                                                                
Station ID: 8724967                         PUBLICATION DATE:  05/06/2003
Name:       MARCO ISLAND, CAXAMBAS PASS                       
            FL
NOAA Chart: 11429                           Latitude:   25° 54.5' N (  25.90830)
USGS Quad:  MARCO ISLAND                    Longitude:  81° 43.7' W ( -81.72830)


                             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.