U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Datums Page Page 1 of 5
PUBLICATION DATE: 12/12/2001
Station ID: 8742947 SUPERCEDED DATE: 04/21/2003
Name: EASTERN OLD FORT BAYOU
MISSISSIPPI
NOAA Chart: NA Latitude: 30° 26.3' N
USGS Quad: PASCAGOULA Longitude: 88° 43.8' W
To reach the tidal bench marks from the intersection of U.S. Highway 90 and
Ocean Springs Road to a dirt drive on the north side of the road, proceed 152 m
(500 ft) north on the dirt drive to the Broussard residence on Old Fort Bayou.
The bench marks are located in the vicinity of the Broussard residence and Ocean
Springs Road. The tide gage and staff were located on the north end of the
Broussard's residence private pier.
T I D A L B E N C H M A R K S
PRIMARY BENCH MARK STAMPING: 2947 A 1979
DESIGNATION: 874 2947 A
MONUMENTATION: Tidal Station disk VM#: 11453
AGENCY: National Ocean Survey (NOS) PID:
SETTING CLASSIFICATION: Stainless steel rod
The primary bench mark is a disk located near the shore of Old Fort Bayou, 17.80
m (58.4 ft) NE of the NE corner of a garage/workshop, 16.89 m (55.4 ft) west of
the NE corner of the Broussard residence, 4.90 m (16.1 ft) NW of the NW corner
of the residence, 4.05 m (13.3 ft) south of the bulkhead on Old Fort Bayou, and
2.90 m (9.5 ft) SW of a 0.91 m (3.0 ft) diameter oak tree. The bench mark is 9
cm (0.3 ft) below ground level, crimped to a stainless steel rod driven 18.3 m
(60 ft) to substantial resistance, and encased in a 4-inch PVC pipe and concrete
kickblock.
BENCH MARK STAMPING: 2947 B 1979
DESIGNATION: 874 2947 B
MONUMENTATION: Tidal Station disk VM#: 11454
AGENCY: National Ocean Survey (NOS) PID:
SETTING CLASSIFICATION: Concrete post
The bench mark is a disk set flush in a concrete post along the west side of the
dirt drive to the Broussard residence, 64.31 m (211.0 ft) south of bench mark
2947 A 1979, 49.14 m (161.2 ft) north of the centerline of Ocean Springs Road,
14 m (46 ft) NW of a 0.46 m (1.5 ft) diameter oak tree, 10.64 m (34.9 ft) east
of a 0.46 m (1.5 ft) diameter palm tree, and 4 m (12 ft) west of the centerline
of the driveway.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 2 of 5
PUBLICATION DATE: 12/12/2001
Station ID: 8742947 SUPERCEDED DATE: 04/21/2003
Name: EASTERN OLD FORT BAYOU
MISSISSIPPI
NOAA Chart: NA Latitude: 30° 26.3' N
USGS Quad: PASCAGOULA Longitude: 88° 43.8' W
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 2947 C 1979
DESIGNATION: 874 2947 C
MONUMENTATION: Tidal Station disk VM#: 11455
AGENCY: National Ocean Survey (NOS) PID:
SETTING CLASSIFICATION: Concrete post
The bench mark is a disk set flush in a concrete post, on the north side of
Ocean Springs Road, 76 m (249 ft) NE of the centerline of the dirt drive to the
Broussard residence, 71 m (233 ft) east of bench mark 2947 B 1979, 18.41 m (60.4
ft) NE of a telephone junction box, 11 m (36 ft) NW of the centerline of Ocean
Springs Road, and 2.41 m (7.9 ft) NW of power pole #B-163 SPC-906-40.
BENCH MARK STAMPING: 2947 D 1979
DESIGNATION: 874 2947 D
MONUMENTATION: Tidal Station disk VM#: 11456
AGENCY: National Ocean Survey (NOS) PID:
SETTING CLASSIFICATION: Stainless steel rod
The bench mark is a disk located 124 m (407 ft) west of bench mark 2947 C 1979,
69 m (226 ft) ENE of the centerline of the Danley driveway, 48 m (157 ft) WSW of
the centerline of the Broussard driveway, 12.31 m (40.4 ft) WSW of power pole
#52, and 9.57 m (31.4 ft) NW of the centerline of Ocean Springs Road. The bench
mark is 12 cm (0.4 ft) below ground level, crimped to a stainless steel rod
driven 16.8 m (55 ft) to substantial resistance, and encased in a 4-inch PVC
pipe and concrete kickblock.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 3 of 5
PUBLICATION DATE: 12/12/2001
Station ID: 8742947 SUPERCEDED DATE: 04/21/2003
Name: EASTERN OLD FORT BAYOU
MISSISSIPPI
NOAA Chart: NA Latitude: 30° 26.3' N
USGS Quad: PASCAGOULA Longitude: 88° 43.8' W
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 2947 E 1979
DESIGNATION: 874 2947 E
MONUMENTATION: Tidal Station disk VM#: 11457
AGENCY: National Ocean Survey (NOS) PID:
SETTING CLASSIFICATION: Stainless steel rod
The bench mark is a disk located 144 m (472 ft) WSW of bench mark 2947 B 1979,
42.64 m (139.9 ft) west of power pole number SREPAB-7705-40, 36.21 m (118.8 ft)
west of a telephone junction, 11.34 m (37.2 ft) NNW of the centerline of Ocean
Springs Road, and 7 m (23 ft) WSW of the centerlne of the Danley driveway. The
bench mark is crimped to a stainless steel rod driven 16.8 m (55 ft) to refusal,
and encased in a 4-inch PVC pipe and concrete kickblock.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 4 of 5
PUBLICATION DATE: 12/12/2001
Station ID: 8742947 SUPERCEDED DATE: 04/21/2003
Name: EASTERN OLD FORT BAYOU
MISSISSIPPI
NOAA Chart: NA Latitude: 30° 26.3' N
USGS Quad: PASCAGOULA Longitude: 88° 43.8' W
T I D A L D A T U M S
Tidal datums at EASTERN OLD FORT BAYOU based on:
LENGTH OF SERIES: 3 MONTHS
TIME PERIOD: February 1980 - April 1980
TIDAL EPOCH: 1960-1978
CONTROL TIDE STATION: 8743735 BILOXI (CADET POINT), BILOXI BAY
Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in METERS:
MEAN HIGHER HIGH WATER MHHW = 0.634
MEAN HIGH WATER MHW = 0.542
MEAN SEA LEVEL MSL = 0.330
MEAN TIDE LEVEL MTL = 0.315
MEAN LOW WATER MLW = 0.089
MEAN LOWER LOW WATER MLLW = 0.000
Bench Mark Elevation Information In METERS above:
Stamping or Designation MLLW MHW
2947 A 1979 1.505 0.963
2947 B 1979 2.365 1.823
2947 C 1979 2.079 1.537
2947 D 1979 2.251 1.709
2947 E 1979 2.072 1.530
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 5 of 5
PUBLICATION DATE: 12/12/2001
Station ID: 8742947 SUPERCEDED DATE: 04/21/2003
Name: EASTERN OLD FORT BAYOU
MISSISSIPPI
NOAA Chart: NA Latitude: 30° 26.3' N
USGS Quad: PASCAGOULA Longitude: 88° 43.8' 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.