U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Datums Page Page 1 of 5
Station ID: 8742205 PUBLICATION DATE: 10/02/2014
Name: GRAVELINE BAYOU ENTRANCE
MS
NOAA Chart: 11373 Latitude: 30° 21.7' N ( 30.36170)
USGS Quad: PASCAGOULA Longitude: 88° 39.8' W ( -88.66330)
T I D A L B E N C H M A R K S
PRIMARY BENCH MARK STAMPING: 2205 A 1980
DESIGNATION: 874 2205 A
MONUMENTATION: Tidal Station disk VM#: 21226
AGENCY: National Ocean Survey IDB PID#:
SETTING CLASSIFICATION: Stainless steel rod OPUS PID:
LATITUDE: 30° 21.7' N ( 30.36170) LONGITUDE: 88° 39.8' W ( -88.66330)
The benchmark is a disk 23.5m (77 ft) N of waters edge (6.1m E of pier), 15.0m
(49.3 ft) W of 36-inch oak, 2.9m (9.8 ft) ESE of SE corner of Pier Graveline
Restaurant, 0.4m (1.4 ft) SW of power pole and 0.1m below grade encased in a pvc
pipe and concrete.
BENCH MARK STAMPING: 2205 B 1980
DESIGNATION: 874 2205 B
MONUMENTATION: Tidal Station disk VM#: 21227
AGENCY: National Ocean Survey IDB PID#:
SETTING CLASSIFICATION: Stainless steel rod OPUS PID:
LATITUDE: 30° 21.7' N ( 30.36170) LONGITUDE: 88° 39.8' W ( -88.66330)
The benchmark is a disk 23.2m (76 ft) NW of 22-inch oak, 19.7m (64.5 ft) W of
30-inch oak, 1.6m (5.3 ft) NNE of edge of drive going through gateway to Point
Clear Rivera Property Owners Inc, 0.4m (1.4 ft) E of 6-foot chainlink fence and
is 0.1m below grade encased in pvc pipe and concrete.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 2 of 5
Station ID: 8742205 PUBLICATION DATE: 10/02/2014
Name: GRAVELINE BAYOU ENTRANCE
MS
NOAA Chart: 11373 Latitude: 30° 21.7' N ( 30.36170)
USGS Quad: PASCAGOULA Longitude: 88° 39.8' W ( -88.66330)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 2205 C 1980
DESIGNATION: 874 2205 C
MONUMENTATION: Tidal Station disk VM#: 21228
AGENCY: National Ocean Survey IDB PID#:
SETTING CLASSIFICATION: Stainless steel rod OPUS PID:
LATITUDE: 30° 21.7' N ( 30.36170) LONGITUDE: 88° 39.8' W ( -88.66330)
The benchmark is a disk 12.6m (41.2 ft) SSE of 52-inch oak, 5.0m (16.5 ft) SE of
centerline of Graveline Road, 4.4m (14.5 ft) NE of power pole, 0.6m (1.9 ft) NNW
of 4-foot chainlink fence and is 0.1m below grade encased in pvc pipe and
concrete.
BENCH MARK STAMPING: 2205 D 1980
DESIGNATION: 874 2205 D
MONUMENTATION: Tidal Station disk VM#: 21229
AGENCY: National Ocean Survey IDB PID#:
SETTING CLASSIFICATION: Stainless steel rod OPUS PID:
LATITUDE: 30° 21.7' N ( 30.36170) LONGITUDE: 88° 39.8' W ( -88.66330)
The benchmark is a disk 18.3m (60 ft) SW of power pole, 13.2m (43.4 ft) W of
centerline to centerline of Graveline Road and paved road which intersects
Graveline Road approximately 115.8m N of Pier Graveline Restaurant, 6.2m (20.4
ft) NW of centerline of Graveline Road and 0.1m below grade encased in a pvc
pipe and concrete.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 3 of 5
Station ID: 8742205 PUBLICATION DATE: 10/02/2014
Name: GRAVELINE BAYOU ENTRANCE
MS
NOAA Chart: 11373 Latitude: 30° 21.7' N ( 30.36170)
USGS Quad: PASCAGOULA Longitude: 88° 39.8' W ( -88.66330)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 2205 E 1980
DESIGNATION: 874 2205 E
MONUMENTATION: Tidal Station disk VM#: 21230
AGENCY: National Ocean Survey IDB PID#:
SETTING CLASSIFICATION: Stainless steel rod OPUS PID:
LATITUDE: 30° 21.7' N ( 30.36170) LONGITUDE: 88° 39.8' W ( -88.66330)
The benchmark is a disk 20m (65.6 ft) E of a 22-inch pine (which is in the
median between Graveline Road and Tarpon Road), 19.2m (63 ft) SE of centerline
of Graveline Road, 13.5m (44.3 ft) SW of power pole and 0.1m below grade encased
in a pvc pipe and concrete.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 4 of 5
Station ID: 8742205 PUBLICATION DATE: 10/02/2014
Name: GRAVELINE BAYOU ENTRANCE
MS
NOAA Chart: 11373 Latitude: 30° 21.7' N ( 30.36170)
USGS Quad: PASCAGOULA Longitude: 88° 39.8' W ( -88.66330)
T I D A L D A T U M S
Tidal datums at GRAVELINE BAYOU ENTRANCE based on:
LENGTH OF SERIES: 1 YEAR
TIME PERIOD: November 1980 - October 1981
TIDAL EPOCH: 1983-2001
CONTROL TIDE STATION: 8747437 BAY WAVELAND YACHT CLUB, BAY ST. LOUIS
Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in METERS:
HIGHEST OBSERVED WATER LEVEL (05/05/1981) = 0.835
MEAN HIGHER HIGH WATER MHHW = 0.498
MEAN HIGH WATER MHW = 0.471
MEAN SEA LEVEL MSL = 0.252
MEAN TIDE LEVEL MTL = 0.251
MEAN LOW WATER MLW = 0.031
MEAN LOWER LOW WATER MLLW = 0.000
LOWEST OBSERVED WATER LEVEL (01/17/1981) = -0.579
North American Vertical Datum (NAVD88)
Bench Mark Elevation Information In METERS above:
Stamping or Designation MLLW MHW
2205 A 1980 4.515 4.044
2205 B 1980 4.808 4.337
2205 C 1980 4.809 4.338
2205 D 1980 5.104 4.633
2205 E 1980 5.060 4.589
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 5 of 5
Station ID: 8742205 PUBLICATION DATE: 10/02/2014
Name: GRAVELINE BAYOU ENTRANCE
MS
NOAA Chart: 11373 Latitude: 30° 21.7' N ( 30.36170)
USGS Quad: PASCAGOULA Longitude: 88° 39.8' W ( -88.66330)
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.