U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
Datums Page                                                        Page  1 of  7

                                                                                
Station ID: 8729102                         PUBLICATION DATE:  06/28/2004
Name:       LYNN HAVEN, NORTH BAY                             
            FL
NOAA Chart: 11390                           Latitude:   30° 15.3' N (  30.25500)
USGS Quad:  SOUTHPORT                       Longitude:  85° 38.9' W ( -85.64830)


To reach the tidal bench marks from city hall in Lynn Haven, proceed north on
State Route 77 for 0.6 km (0.4 mi) to Ohio Avenue, then continue north on Ohio
Avenue for 0.3 km (0.2 mi) to the south edge of North Bay. The bench marks are
located in area between North Bay Bridge and a privatly owned pier just west of
the bridge. The tide gage and staff were located on the NE corner of the
privatly owned pier.


                         T I D A L   B E N C H   M A R K S
                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  2 of  7

                                                                                
Station ID: 8729102                         PUBLICATION DATE:  06/28/2004
Name:       LYNN HAVEN, NORTH BAY                             
            FL
NOAA Chart: 11390                           Latitude:   30° 15.3' N (  30.25500)
USGS Quad:  SOUTHPORT                       Longitude:  85° 38.9' W ( -85.64830)


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


                 PRIMARY BENCH MARK STAMPING:  LYNN HAVEN NO 1 1935
                         DESIGNATION:          LYNN HAVEN 1

MONUMENTATION:           Tidal Station disk                    VM#:         9991
AGENCY:                  US Coast and Geodetic Survey
                         (USC&GS)                              IDB PID#:  BE0656
SETTING CLASSIFICATION:  Concrete monument                     OPUS PID:        
LATITUDE:   30° 15.3' N (  30.25500)          LONGITUDE:   8° 39.0' W (  -8.65000)


The primary bench mark is a disk set in the top of concrete filled tile
monument, 61.26 m (201.0 ft) east of bench mark LYNN HAVEN NO 2 1935, 57.61 m
(189.0 ft) WSW of and across a small bayou from the SW corner of the State
Highway 77 bridge over North Bay, 19.81 m (65.0 ft) south of the shoreline of
North Bay, 19.20 m (63.0 ft) west of the west edge of the bayou, 13.72 m (45.0
ft) NE of the NE corner of a house, 7.16 m (23.5 ft) south of a 0.61 m (2.0 ft)
diameter pine tree, 6.40 m (21.0 ft) east of a 0.61 m (2.0 ft) diameter magnolia
tree, and 9 cm (0.3 ft) above ground level. NOTE: Mark not found in 1994 by US
Power Squadron.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  3 of  7

                                                                                
Station ID: 8729102                         PUBLICATION DATE:  06/28/2004
Name:       LYNN HAVEN, NORTH BAY                             
            FL
NOAA Chart: 11390                           Latitude:   30° 15.3' N (  30.25500)
USGS Quad:  SOUTHPORT                       Longitude:  85° 38.9' W ( -85.64830)


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


                         BENCH MARK STAMPING:  LYNN HAVEN NO 2 1935
                         DESIGNATION:          LYNN HAVEN 2

MONUMENTATION:           Tidal Station disk                    VM#:         9992
AGENCY:                  US Coast and Geodetic Survey
                         (USC&GS)                              IDB PID#:  BE0657
SETTING CLASSIFICATION:  Concrete monument                     OPUS PID:        
LATITUDE:   30° 15.3' N (  30.25500)          LONGITUDE:   8° 39.0' W (  -8.65000)


The bench mark is a disk set in the top of a concrete-filled tile monument,
65.23 m (214.0 ft) south of the shoreline of North Bay, 61 m (200 ft) SW of
bench mark LYNN HAVEN NO 1 1935, 33.83 m (111.0 ft) SE of the SE corner of a
large brick house, 20.42 m (67.0 ft) east of the extended centerline of Ohio
Avenue, 8.53 m (28.0 ft) SW of a powerline pole with two transformers, and 9 cm
(0.3 ft) above ground level.  NOTE: Mark not found in 1994 by US Power Squadron.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  4 of  7

                                                                                
Station ID: 8729102                         PUBLICATION DATE:  06/28/2004
Name:       LYNN HAVEN, NORTH BAY                             
            FL
NOAA Chart: 11390                           Latitude:   30° 15.3' N (  30.25500)
USGS Quad:  SOUTHPORT                       Longitude:  85° 38.9' W ( -85.64830)


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


                         BENCH MARK STAMPING:  LYNN HAVEN NO 3 1935
                         DESIGNATION:          LYNN HAVEN 3

MONUMENTATION:           Tidal Station disk                    VM#:         9993
AGENCY:                  US Coast and Geodetic Survey
                         (USC&GS)                              IDB PID#:  BE0658
SETTING CLASSIFICATION:  Concrete monument                     OPUS PID:        
LATITUDE:   30° 15.3' N (  30.25500)          LONGITUDE:   8° 39.0' W (  -8.65000)


The bench mark is a disk set in the top of a concrete-filled tile monument, 61 m
(200 ft) west of bench mark LYNN HAVEN NO 1 1935, 51.36 m (168.5 ft) NW of bench
mark Lynn Haven No 2 1935,  39.62 m (130.0 ft) west of the NW corner of a wood
frame house, 32 m (105 ft) NE of the NE corner of a large brick house, 29.87 m
(98.0 ft) south of the shoreline of North Bay, 2.74 m (9.0 ft) SW of an inplace
lawn sprinkler, and 6 cm (0.2 ft) above ground level. NOTE: Mark not found in
1994 by US Power Squadron.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  5 of  7

                                                                                
Station ID: 8729102                         PUBLICATION DATE:  06/28/2004
Name:       LYNN HAVEN, NORTH BAY                             
            FL
NOAA Chart: 11390                           Latitude:   30° 15.3' N (  30.25500)
USGS Quad:  SOUTHPORT                       Longitude:  85° 38.9' W ( -85.64830)


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


                         BENCH MARK STAMPING:  X 290 1967
                         DESIGNATION:          X 290

MONUMENTATION:           Bench Mark disk                       VM#:         9994
AGENCY:                  US Coast and Geodetic Survey
                         (USC&GS)                              IDB PID#:  BE0655
SETTING CLASSIFICATION:  Concrete bridge abutment              OPUS PID:        
LATITUDE:   30° 15.3' N (  30.25500)          LONGITUDE:   8° 38.9' W (  -8.64833)


The bench mark is a disk set in top of the west end of the south concrete
abutment of the State Highway 77 bridge over North Bay, 5.64 m (18.5 ft) west of
the centerline of the highway, and 0.3 m (1 ft) above the level of the highway,
and 0.30 m (1 ft) above the level of the highway. NOTE: Mark not found in 1999
by US Power Squadron.



                         BENCH MARK STAMPING:  NO 8 1975
                         DESIGNATION:          872 9102 TIDAL 8

MONUMENTATION:           Tidal Station disk                    VM#:         9995
AGENCY:                  National Ocean Survey (NOS)           IDB PID#:  BE1713
SETTING CLASSIFICATION:  Concrete drainage basin               OPUS PID#: BE1713
LATITUDE:   30° 15.2' N (  30.25330)          LONGITUDE:   8° 38.9' W (  -8.64833)


The bench mark is a disk set flush in the corner of a concrete box drain along a
drive leading from State Route 77 to Leslie Porter Park, 30.48 m (100.0 ft) east
of the centerline of State Route 77, 19.45 m (63.8 ft) east of a wooden light
pole, 5.79 m (19.0 ft) south of the centerline of the drive to Leslie Porter
Park, and 2.50 m (8.2 ft) north of the edge of a cement culvert.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  6 of  7

                                                                                
Station ID: 8729102                         PUBLICATION DATE:  06/28/2004
Name:       LYNN HAVEN, NORTH BAY                             
            FL
NOAA Chart: 11390                           Latitude:   30° 15.3' N (  30.25500)
USGS Quad:  SOUTHPORT                       Longitude:  85° 38.9' W ( -85.64830)


                            T I D A L   D A T U M S 


Tidal datums at LYNN HAVEN, NORTH BAY based on:

     LENGTH OF SERIES:      1 YEAR
     TIME PERIOD:           January 1976 - December 1976
     TIDAL EPOCH:           1983-2001
     CONTROL TIDE STATION:  8729840 PENSACOLA, PENSACOLA BAY


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

     HIGHEST OBSERVED WATER LEVEL (12/25/1975)         =  1.002
     MEAN HIGHER HIGH WATER                     MHHW   =  0.448
     MEAN HIGH WATER                            MHW    =  0.412
     MEAN TIDE LEVEL                            MTL    =  0.222
     MEAN SEA LEVEL                             MSL    =  0.220
     North American Vertical Datum              NAVD88 =  0.173
     MEAN LOW WATER                             MLW    =  0.032
     MEAN LOWER LOW WATER                       MLLW   =  0.000
     LOWEST  OBSERVED WATER LEVEL (01/27/1987)         = -0.854

North American Vertical Datum (NAVD88)

Bench Mark Elevation Information                In METERS above:

     Stamping or Designation                    MLLW        MHW

     LYNN HAVEN NO 1 1935                        2.243    1.831
     LYNN HAVEN NO 2 1935                        2.866    2.454
     LYNN HAVEN NO 3 1935                        2.474    2.062
     X 290 1967                                  2.754    2.342
     NO 8 1975                                   1.874    1.462


                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  7 of  7

                                                                                
Station ID: 8729102                         PUBLICATION DATE:  06/28/2004
Name:       LYNN HAVEN, NORTH BAY                             
            FL
NOAA Chart: 11390                           Latitude:   30° 15.3' N (  30.25500)
USGS Quad:  SOUTHPORT                       Longitude:  85° 38.9' W ( -85.64830)


                             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.