U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Datums Page Page 1 of 6
Station ID: 8729387 PUBLICATION DATE: 01/23/2004
Name: BASIN BAYOU, CHOCTAWHATCHEE BAY
FL
NOAA Chart: 11388 Latitude: 30° 29.2' N ( 30.48670)
USGS Quad: CHOCTAW BEACH Longitude: 86° 15.2' W ( -86.25330)
To reach the tidal bench marks from the intersection of State Highway 20 and
U.S. Highway 331 in Freeport, proceed 12.4 km (7.7 mi) west along Highway 20 to
the highway bridge over Basin Bayou. The bench marks are along State Highway
20. The tide gage and staff were located on the Nicks Sea Food Restaurant dock
at entrance to the bayou.
T I D A L B E N C H M A R K S
PRIMARY BENCH MARK STAMPING: 9387 A 1977
DESIGNATION: 872 9387 A TIDAL
MONUMENTATION: Tidal Station disk VM#: 10111
AGENCY: National Ocean Survey (NOS) IDB PID#: BG3584
SETTING CLASSIFICATION: Concrete bridge railing OPUS PID:
LATITUDE: 30° 29.2' N ( 30.48670) LONGITUDE: 86° 15.1' W ( -86.25170)
The primary bench mark is a disk set in top of the concrete railing at the east
corner of the State Highway 20 bridge over Basin Bayou, 6.80 m (22.3 ft) NE of
the centerline of the highway, and 0.91 m (3.0 ft) above highway level.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 2 of 6
Station ID: 8729387 PUBLICATION DATE: 01/23/2004
Name: BASIN BAYOU, CHOCTAWHATCHEE BAY
FL
NOAA Chart: 11388 Latitude: 30° 29.2' N ( 30.48670)
USGS Quad: CHOCTAW BEACH Longitude: 86° 15.2' W ( -86.25330)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 2 1939
DESIGNATION: 872 9387 TIDAL 2
MONUMENTATION: Tidal Station disk VM#: 10112
AGENCY: US Coast and Geodetic Survey
(USC&GS) IDB PID#: BG2181
SETTING CLASSIFICATION: Concrete monument OPUS PID:
LATITUDE: 30° 29.2' N ( 30.48670) LONGITUDE: 86° 15.1' W ( -86.25170)
The bench mark is a disk set into the top of a concrete monument, 0.24 km (0.15
mi) west of the bridge over Basin Bayou, 76 m (249 ft) SW of bench mark N 292
1967, 64 m (209 ft) south of the centerline of State Highway 20, 27.13 m (89.0
ft) north of the north shore of Choctawhatchee Bay, 24.84 m (81.5 ft) NE of the
NE corner of the second house west of the bridge, 1.22 m (4.0 ft) north of the
centerline of a trail, and 0.06 m (0.2 ft) above ground level.
BENCH MARK STAMPING: 3 RESET 1975
DESIGNATION: 872 9387 TIDAL 3 1975
MONUMENTATION: Tidal Station disk VM#: 10113
AGENCY: US Coast and Geodetic Survey
(USC&GS) IDB PID#: BG0214
SETTING CLASSIFICATION: Concrete bridge rail OPUS PID:
LATITUDE: 30° 29.2' N ( 30.48670) LONGITUDE: 86° 15.1' W ( -86.25170)
The bench mark is a disk set in top of the concrete railing at the west corner
of the State Highway 20 bridge over Basin Bayou, 7 m (23 ft) SW of the
centerline of the highway, 1.07 m (3.5 ft) SE of the NW end of the railing, and
0.91 m (3.0 ft) above the level of the highway.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 3 of 6
Station ID: 8729387 PUBLICATION DATE: 01/23/2004
Name: BASIN BAYOU, CHOCTAWHATCHEE BAY
FL
NOAA Chart: 11388 Latitude: 30° 29.2' N ( 30.48670)
USGS Quad: CHOCTAW BEACH Longitude: 86° 15.2' W ( -86.25330)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: M 292 1967
DESIGNATION: M 292
MONUMENTATION: Bench Mark disk VM#: 10114
AGENCY: US Coast and Geodetic Survey
(USC&GS) IDB PID#: BG2194
SETTING CLASSIFICATION: Concrete monument OPUS PID:
LATITUDE: 30° 29.1' N ( 30.48500) LONGITUDE: 86° 14.7' W ( -86.24500)
The bench mark is a disk set in the top of a concrete monument, 0.6 km (0.4 mi)
east of the State Highway 20 bridge over Basin Bayou, 19.20 m (63.0 ft) north of
the centerline of the highway, 17.68 m (58.0 ft) NW of the west end of a
concrete culvert, 16.46 m (54.0 ft) west of the centerline of a private
driveway, 0.91 m (3.0 ft) east of a powerline pole with a transformer, 0.61 m
(2.0 ft) west of a witness post, and 0.09 m (0.03 ft) above ground level.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 4 of 6
Station ID: 8729387 PUBLICATION DATE: 01/23/2004
Name: BASIN BAYOU, CHOCTAWHATCHEE BAY
FL
NOAA Chart: 11388 Latitude: 30° 29.2' N ( 30.48670)
USGS Quad: CHOCTAW BEACH Longitude: 86° 15.2' W ( -86.25330)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: N 292 1967
DESIGNATION: N 292
MONUMENTATION: Bench Mark disk VM#: 10115
AGENCY: US Coast and Geodetic Survey
(USC&GS) IDB PID#: BG2179
SETTING CLASSIFICATION: Concrete monument OPUS PID:
LATITUDE: 30° 29.3' N ( 30.48830) LONGITUDE: 86° 15.1' W ( -86.25170)
The bench mark is a disk set in the top of a concrete moment, 196 m (643 ft)
west of the west end of the State Highway 20 bridge over Basin Bayou, 29 m (95
ft) NW of the NW corner of a house, 20.12 m (66.0 ft) east of the centerline of
a driveway, 15.39 m (50.5 ft) west of the centerline of another driveway, 15.24
m (50.0 ft) south of the centerline of the highway, and at ground level.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 5 of 6
Station ID: 8729387 PUBLICATION DATE: 01/23/2004
Name: BASIN BAYOU, CHOCTAWHATCHEE BAY
FL
NOAA Chart: 11388 Latitude: 30° 29.2' N ( 30.48670)
USGS Quad: CHOCTAW BEACH Longitude: 86° 15.2' W ( -86.25330)
T I D A L D A T U M S
Tidal datums at BASIN BAYOU, CHOCTAWHATCHEE BAY based on:
LENGTH OF SERIES: 2 MONTHS
TIME PERIOD: October 1977 - November 1977
TIDAL EPOCH: 1983-2001
CONTROL TIDE STATION: 8729538 GARNIER BAYOU, SHALIMAR
Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in METERS:
MEAN HIGHER HIGH WATER MHHW = 0.123
MEAN HIGH WATER MHW = 0.114
MEAN SEA LEVEL MSL = 0.062
MEAN TIDE LEVEL MTL = 0.059
MEAN LOW WATER MLW = 0.004
MEAN LOWER LOW WATER MLLW = 0.000
North American Vertical Datum NAVD88 = -0.048
North American Vertical Datum (NAVD88)
Bench Mark Elevation Information In METERS above:
Stamping or Designation MLLW MHW
9387 A 1977 3.163 3.049
2 1939 0.870 0.756
3 RESET 1975 3.169 3.055
M 292 1967 2.920 2.806
N 292 1967 0.729 0.615
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 6 of 6
Station ID: 8729387 PUBLICATION DATE: 01/23/2004
Name: BASIN BAYOU, CHOCTAWHATCHEE BAY
FL
NOAA Chart: 11388 Latitude: 30° 29.2' N ( 30.48670)
USGS Quad: CHOCTAW BEACH Longitude: 86° 15.2' W ( -86.25330)
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.