U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Datums Page Page 1 of 7
Station ID: 8761414 PUBLICATION DATE: 04/16/2018
Name: BILLET BAY COMMUNITY, BILLET BAY
LA
NOAA Chart: 11358 Latitude: 29° 22.3' N ( 29.37170)
USGS Quad: BAY RONQUILLE Longitude: 89° 45.1' W ( -89.75170)
To reach the tidal bench marks from Hi Ridge Marina at the north side of Port
Sulphur, proceed by boat SW in the marina canal to Grand Bayou, then turn left
into Grand Bayou and proceed SE to the Freeport Sulphur Company Canal, then turn
right into the canal and proceed SW to Rattlesnake Bayou, then turn left into
the bayou (Rosewood Resources, Inc. Compressor Station is on the left) and
proceed about 1.6 km (1.0 mi) to Robinson Canal, then turn right into the canal
and proceed about 2.4 km (1.5 mi) to Billet Bay Community and the sheriff's camp
with an American flag atop the camp. The bench marks are located in the
vicinity of the sheriff's camp and SE along the marsh the camp is on. The tide
gage and staff were located on the southernmost corner of the sheriff's wharf.
Note: A recent fishing map available at Hi Ridge Marina is useful in finding
this site.
T I D A L B E N C H M A R K S
PRIMARY BENCH MARK STAMPING: 1414 A 1985
DESIGNATION: 876 1414 A TIDAL
MONUMENTATION: Tidal Station disk VM#: 7161
AGENCY: National Ocean Service (NOS) IDB PID#:
SETTING CLASSIFICATION: Stainless steel rod OPUS PID:
LATITUDE: 29° 22.3' N ( 29.37170) LONGITUDE: 89° 45.1' W ( -89.75170)
The primary bench mark is a disk located in the marsh near the easternmost
corner of the sheriff's camp, 42.37 m (139.0 ft) east of the first power pole NW
of the sheriff's camp, 10.12 m (33.2 ft) north of the SE corner support pile of
the sheriff's camp, 10 m (33 ft) east of the NE corner support pile on the
sheriff's camp, and 0.30 m (1.0 ft) south of a witness post. The bench mark is
set 0.24 m (0.8 ft) above ground level, crimped to the top of a stainless steel
rod driven 20.7 m (68 ft) to substantial resistance and encased in a 5-inch PVC
pipe and concrete kickblock.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 2 of 7
Station ID: 8761414 PUBLICATION DATE: 04/16/2018
Name: BILLET BAY COMMUNITY, BILLET BAY
LA
NOAA Chart: 11358 Latitude: 29° 22.3' N ( 29.37170)
USGS Quad: BAY RONQUILLE Longitude: 89° 45.1' W ( -89.75170)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 1414 B 1985
DESIGNATION: 876 1414 B TIDAL
MONUMENTATION: Tidal Station disk VM#: 7162
AGENCY: National Ocean Service (NOS) IDB PID#:
SETTING CLASSIFICATION: Stainless steel rod OPUS PID:
LATITUDE: 29° 22.3' N ( 29.37170) LONGITUDE: 89° 45.1' W ( -89.75170)
The bench mark is a disk located SE of the sheriff's camp, 79.55 m (261.0 ft)
SSE of bench mark 1414 A 1985, 33 m (108 ft) NE of the northernmost corner
support pile of the second camp SE of the sheriff's camp, 31 m (101 ft) NE of
the northernmost corner support pile of the first camp SE of the sheriff's camp,
4.18 m (13.7 ft) WSW of a 2-inch pine pole extending 2 m (8 ft) above the marsh,
and 0.30 m (1.0 ft) WSW of a witness post. The bench mark is set 9 cm (0.3 ft)
above ground level, crimped to the top of a stainless steel rod driven 21.9 m
(72 ft) to substantial resistance, and encased in a 5-inch PVC pipe and concrete
kickblock.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 3 of 7
Station ID: 8761414 PUBLICATION DATE: 04/16/2018
Name: BILLET BAY COMMUNITY, BILLET BAY
LA
NOAA Chart: 11358 Latitude: 29° 22.3' N ( 29.37170)
USGS Quad: BAY RONQUILLE Longitude: 89° 45.1' W ( -89.75170)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 1414 C 1985
DESIGNATION: 876 1414 C TIDAL
MONUMENTATION: Tidal Station disk VM#: 7163
AGENCY: National Ocean Service (NOS) IDB PID#:
SETTING CLASSIFICATION: Stainless steel rod OPUS PID:
LATITUDE: 29° 22.3' N ( 29.37170) LONGITUDE: 89° 45.1' W ( -89.75170)
The bench mark is a disk located 84.73 m (278.0 ft) SE of bench mark 1414 B
1985, 41.30 m (135.5 ft) north of the third utility pole SE of the sheriff's
camp, 15.70 m (51.5 ft) SSE of the easternmost corner support pile of a red
metal storage shed, 3 m (10 ft) ENE of the northernmost corner of an old wood
shed located at the rear of an abandoned dry dock ramp, 3 m (10 ft) NNE of the
easternmost corner of the old wood shed, and 0.58 m (1.9 ft) SW of a witness
post. The bench mark is set 0.15 m (0.5 ft) above ground level, crimped to the
top of a stainless steel rod driven 21.9 m (72 ft) to substantial resistance,
and encased in a 5-inch PVC pipe and concrete kickblock.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 4 of 7
Station ID: 8761414 PUBLICATION DATE: 04/16/2018
Name: BILLET BAY COMMUNITY, BILLET BAY
LA
NOAA Chart: 11358 Latitude: 29° 22.3' N ( 29.37170)
USGS Quad: BAY RONQUILLE Longitude: 89° 45.1' W ( -89.75170)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 1414 D 1985
DESIGNATION: 876 1414 D TIDAL
MONUMENTATION: Tidal Station disk VM#: 7164
AGENCY: National Ocean Service (NOS) IDB PID#:
SETTING CLASSIFICATION: Stainless steel rod OPUS PID:
LATITUDE: 29° 22.3' N ( 29.37170) LONGITUDE: 89° 45.1' W ( -89.75170)
The bench mark is a disk located SE of the sheriff's camp, 63.64 m (208.8 ft) SE
of bench mark 1414 C 1985, 17 m (55 ft) ENE of the face of the white cistern on
the SE side of the camp Gazebo, 9.36 m (30.7 ft) ENE of an old jack supporting
the easternmost corner of camp Gazebo, 9.33 m (30.6 ft) east of the easternmost
pile supporting the cistern behind camp Gazebo, and 0.58 m (1.9 ft) SW of a
witness post. The bench mark is set at ground level, crimped to the top of a
stainless steel rod driven 21.9 m (72 ft) to substantial resistance, and encased
in a 5-inch PVC pipe and concrete kickblock.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 5 of 7
Station ID: 8761414 PUBLICATION DATE: 04/16/2018
Name: BILLET BAY COMMUNITY, BILLET BAY
LA
NOAA Chart: 11358 Latitude: 29° 22.3' N ( 29.37170)
USGS Quad: BAY RONQUILLE Longitude: 89° 45.1' W ( -89.75170)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 1414 E 1985
DESIGNATION: 876 1414 E TIDAL
MONUMENTATION: Tidal Station disk VM#: 7165
AGENCY: National Ocean Service (NOS) IDB PID#:
SETTING CLASSIFICATION: Stainless steel rod OPUS PID:
LATITUDE: 29° 22.3' N ( 29.37170) LONGITUDE: 89° 45.1' W ( -89.75170)
The bench mark is a disk located on the SE tip of the strip of marsh that the
sheriff's camp is on, 63.86 m (209.5 ft) SSE of bench mark 1414 D 1985, 38.01 m
(124.7 ft) SE of the southeasternmost utility pole on the strip of marsh, 18.32
m (60.1 ft) ESE of the southernmost pile supporting the porch of camp Old
Caboose, 18.29 m (60.0 ft) SSE of the easternmost corner of camp Old Caboose,
11.28 m (37.0 ft) north of the north edge of a 4-pile cluster at the tip of the
strip of marsh, and 0.18 m (0.6 ft) SE of a witness post. The bench mark is set
at ground level, crimped to the top of a stainless steel rod driven 20.7 m (68
ft) to substantial resistance, and encased in a 5-inch PVC pipe and concrete
kickblock.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 6 of 7
Station ID: 8761414 PUBLICATION DATE: 04/16/2018
Name: BILLET BAY COMMUNITY, BILLET BAY
LA
NOAA Chart: 11358 Latitude: 29° 22.3' N ( 29.37170)
USGS Quad: BAY RONQUILLE Longitude: 89° 45.1' W ( -89.75170)
T I D A L D A T U M S
Tidal datums at BILLET BAY COMMUNITY, BILLET BAY based on:
LENGTH OF SERIES: 1 YEAR
TIME PERIOD: November 1985 - October 1986
TIDAL EPOCH: 2012-2016
CONTROL TIDE STATION: 8761724 GRAND ISLE, EAST POINT
Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in METERS:
HIGHEST OBSERVED WATER LEVEL (10/28/1985) = 1.203
MEAN HIGHER HIGH WATER MHHW = 0.322
MEAN HIGH WATER MHW = 0.319
MEAN TIDE LEVEL MTL = 0.164
MEAN SEA LEVEL MSL = 0.163
MEAN LOW WATER MLW = 0.009
MEAN LOWER LOW WATER MLLW = 0.000
LOWEST OBSERVED WATER LEVEL (03/22/1986) = -0.662
North American Vertical Datum (NAVD88)
Bench Mark Elevation Information In METERS above:
Stamping or Designation MLLW MHW
1414 A 1985 0.027 -0.292
1414 B 1985 0.082 -0.237
1414 C 1985 0.079 -0.240
1414 D 1985 0.460 0.141
1414 E 1985 0.376 0.057
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 7 of 7
Station ID: 8761414 PUBLICATION DATE: 04/16/2018
Name: BILLET BAY COMMUNITY, BILLET BAY
LA
NOAA Chart: 11358 Latitude: 29° 22.3' N ( 29.37170)
USGS Quad: BAY RONQUILLE Longitude: 89° 45.1' W ( -89.75170)
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.