U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Datums Page Page 1 of 8
Station ID: 8737048 PUBLICATION DATE: 02/16/2018
Name: MOBILE STATE DOCKS, MOBILE RIVER
AL
NOAA Chart: 11376 Latitude: 30° 42.5' N ( 30.70830)
USGS Quad: MOBILE Longitude: 88° 2.6' W ( -88.04330)
To reach the tidal bench marks from the Water Street (State Route 43) exit on
Interstate Highway 10 in Mobile, proceed north on Water Street for 2.3 km (1.4
mi) to Beauregard Street, then east on Beauregard Street for 0.3 km (0.2 mi) to
Delchamps Street, then north on Delchamps Street for 0.3 km (0.2 mi) to the
Mobile State Docks security office. The bench marks are on the Mobile State
Docks facility. The tide gage and staff were at the east end of Pier A South
(just south of bench mark 7048 A 1980).
T I D A L B E N C H M A R K S
PRIMARY BENCH MARK STAMPING: 7048 C 2002
DESIGNATION: 873 7048 C
MONUMENTATION: Tidal Station disk VM#: 16645
AGENCY: National Ocean Service (NOS) IDB PID#:
SETTING CLASSIFICATION: Massive concrete ramp OPUS PID:
LATITUDE: 30° 42.6' N ( 30.70961) LONGITUDE: 88° 2.6' W ( -88.04261)
The primary bench mark is a disk set flush in the concrete, located on a loading
ramp between Pier A South and Berth 8, 25.66 m (84.19 ft) north of a yellow
bollard on the loading ramp, 5.18 m (16.99 ft) south of the south rail of the
railroad tracks, 1.9 m (6.2 ft) west of the east edge of the bulkhead, and 0.80
m (2.62 ft) below the concrete ledge of the retaining wall with a metal railing.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 2 of 8
Station ID: 8737048 PUBLICATION DATE: 02/16/2018
Name: MOBILE STATE DOCKS, MOBILE RIVER
AL
NOAA Chart: 11376 Latitude: 30° 42.5' N ( 30.70830)
USGS Quad: MOBILE Longitude: 88° 2.6' W ( -88.04330)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: Y 9 RESET 1946
DESIGNATION: Y 9 RESET
MONUMENTATION: Survey disk VM#: 10358
AGENCY: US Coast and Geodetic Survey
(US&CGS) IDB PID#: BH0056
SETTING CLASSIFICATION: Building OPUS PID:
LATITUDE: 30° 42.0' N ( 30.70028) LONGITUDE: 88° 2.7' W ( -88.04569)
The bench mark is a disk set vertically in the south brick face of the third
column east of St. Joseph Street, on the south side of the Gulf Mobile & Ohio
Company building at the NE corner of the intersectin of St. Joseph and
Beauregard Streets, 12.0 m (39.4 ft) north of the west end of a sign, 9.4 m
(30.8 ft) east of the east curb of St. Joseph Street, 4.10 m (13.45 ft) east of
the east face of the building, 1.4 m (4.6 ft) above a concrete parking ramp.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 3 of 8
Station ID: 8737048 PUBLICATION DATE: 02/16/2018
Name: MOBILE STATE DOCKS, MOBILE RIVER
AL
NOAA Chart: 11376 Latitude: 30° 42.5' N ( 30.70830)
USGS Quad: MOBILE Longitude: 88° 2.6' W ( -88.04330)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: N 406 1955
DESIGNATION: N 406
MONUMENTATION: Bench Mark disk VM#: 10359
AGENCY: US Coast and Geodetic Survey
(USC&GS) IDB PID#: BH1470
SETTING CLASSIFICATION: Building foundation OPUS PID:
LATITUDE: 30° 41.7' N ( 30.69419) LONGITUDE: 88° 2.6' W ( -88.04303)
The bench mark is a disk set vertically in the north face of the U.S. Court
House and Custom House building, 7.0 m (23.0 ft) west of the west curb of St.
Joseph Street, 5 .2 m (17.1 ft) south of the south curb of St. Louis Street,
0.80 m (2.6 ft) west of the NE corner of the building, and 0.3 m (0.98 ft) above
the ground.
BENCH MARK STAMPING: 7048 A 1980
DESIGNATION: 873 7048 A
MONUMENTATION: Tidal Station disk VM#: 10360
AGENCY: National Ocean Survey (NOS) IDB PID#:
SETTING CLASSIFICATION: Concrete pier OPUS PID:
LATITUDE: 30° 42.3' N ( 30.70456) LONGITUDE: 88° 2.4' W ( -88.03958)
The bench mark is a disk set flush with the concrete at the east end of Pier A,
below and just south of a metal stairway, 8.5 m (27.9 ft) west of the east dock
wall, 2.43 m (7.97 ft) north of the center of a metal stairways, and 1.50 m
(4.92 ft) south of the south wall of a concrete warehouse.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 4 of 8
Station ID: 8737048 PUBLICATION DATE: 02/16/2018
Name: MOBILE STATE DOCKS, MOBILE RIVER
AL
NOAA Chart: 11376 Latitude: 30° 42.5' N ( 30.70830)
USGS Quad: MOBILE Longitude: 88° 2.6' W ( -88.04330)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 7048 D 2002
DESIGNATION: 873 7048 D
ALIAS: 7048 D
MONUMENTATION: Tidal Station disk VM#: 16646
AGENCY: National Ocean Service (NOS) IDB PID#:
SETTING CLASSIFICATION: Concrete ramp OPUS PID#: DN4335
LATITUDE: 30° 42.2' N ( 30.70367) LONGITUDE: 88° 2.5' W ( -88.04125)
The bench mark is a disk set flush in the concrete, located on the south side of
a loading ramp on the west side of piers between Pier A South and Berth 8,
28.01m (91.90 ft) south of the center of a loading ramp between Pier A South and
Berth 8, 11.40 m (37.40 ft) NW of the WNW corner of a building at Berth 8, 2.0 m
(6.6 ft) west of the bulkhead on the loading ramp, 1.64 m (5.38 ft) below a
concrete wall on the south end of the loading ramp.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 5 of 8
Station ID: 8737048 PUBLICATION DATE: 02/16/2018
Name: MOBILE STATE DOCKS, MOBILE RIVER
AL
NOAA Chart: 11376 Latitude: 30° 42.5' N ( 30.70830)
USGS Quad: MOBILE Longitude: 88° 2.6' W ( -88.04330)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: J 445 1980
DESIGNATION: J 445
MONUMENTATION: Bench Mark disk VM#: 18294
AGENCY: NGS IDB PID#: BH1581
SETTING CLASSIFICATION: Structure OPUS PID:
LATITUDE: 30° 41.8' N ( 30.69708) LONGITUDE: 88° 2.6' W ( -88.04397)
The bench mark is a disk set vertically in the west corner of the post office at
the junction of St. Joseph and Congress Streets, 21.4 m (70.2 ft) NE of the NE
curb of ST. Joseph Street, 5.7 m (18.7 ft) SE of the SE curb of Congress Street,
0.30 m (0.98 ft) NE of the west corner of the post office, and 1.25 m (4.10 ft)
above the ground.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 6 of 8
Station ID: 8737048 PUBLICATION DATE: 02/16/2018
Name: MOBILE STATE DOCKS, MOBILE RIVER
AL
NOAA Chart: 11376 Latitude: 30° 42.5' N ( 30.70830)
USGS Quad: MOBILE Longitude: 88° 2.6' W ( -88.04330)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: MOBILE HARBOR 233 1939
DESIGNATION: USED 233
MONUMENTATION: Tidal Station disk VM#: 18775
AGENCY: US Engineers Department IDB PID#:
SETTING CLASSIFICATION: Concrete Dock OPUS PID:
LATITUDE: 30° 42.3' N ( 30.70442) LONGITUDE: 88° 2.4' W ( -88.03956)
The bench mark is a disk set flush in the concrete at pier A at the east end of
the dock on the lower part of the dock, 7.28 m (23.88 ft) ENE of BM 7048 A, 4.14
m (13.58 ft) East of the East face of a concrete warehouse wall, 0.43 m (1.411
ft) west of an orange bollard.
BENCH MARK STAMPING: 7048 E 2009
DESIGNATION: 873 7048 E
MONUMENTATION: Bench Mark disk VM#: 19516
AGENCY: National Ocean Service (NOS) IDB PID#:
SETTING CLASSIFICATION: Concrete pier OPUS PID#: DN4337
LATITUDE: 30° 42.3' N ( 30.70450) LONGITUDE: 88° 2.4' W ( -88.03967)
The bench mark is a disk set in a bulkhead, located 11.38 m (37.34 ft) west of
the northern corner of the bulkhead, 11.16 m (36.61 ft) SE of the corner closest
to the garage, 8.76 m (28.74 ft) south of the south corner to the ladder of the
tide gauge, and 5.20 m (17.06 ft) west of the corner of the orange bollard to
the north.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 7 of 8
Station ID: 8737048 PUBLICATION DATE: 02/16/2018
Name: MOBILE STATE DOCKS, MOBILE RIVER
AL
NOAA Chart: 11376 Latitude: 30° 42.5' N ( 30.70830)
USGS Quad: MOBILE Longitude: 88° 2.6' W ( -88.04330)
T I D A L D A T U M S
Tidal datums at MOBILE STATE DOCKS, MOBILE RIVER based on:
LENGTH OF SERIES: 10 YEARS
TIME PERIOD: July 2007 - June 2017
TIDAL EPOCH: 1983-2001
CONTROL TIDE STATION: 8741533 PASCAGOULA NOAA LAB, PASCAGOULA RIVER
Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in METERS:
HIGHEST OBSERVED WATER LEVEL (10/08/2017) = 2.053
MEAN HIGHER HIGH WATER MHHW = 0.502
MEAN HIGH WATER MHW = 0.476
MEAN TIDE LEVEL MTL = 0.252
MEAN SEA LEVEL MSL = 0.251
North American Vertical Datum NAVD88 = 0.149
MEAN LOW WATER MLW = 0.028
MEAN LOWER LOW WATER MLLW = 0.000
LOWEST OBSERVED WATER LEVEL (01/20/1985) = -0.866
North American Vertical Datum (NAVD88)
Bench Mark Elevation Information In METERS above:
Stamping or Designation MLLW MHW
7048 C 2002 1.632 1.156
Y 9 RESET 1946 3.624 3.148
N 406 1955 3.357 2.881
7048 A 1980 1.693 1.217
7048 D 2002 1.627 1.151
J 445 1980 3.543 3.067
MOBILE HARBOR 233 1939 1.664 1.188
7048 E 2009 3.174 2.698
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 8 of 8
Station ID: 8737048 PUBLICATION DATE: 02/16/2018
Name: MOBILE STATE DOCKS, MOBILE RIVER
AL
NOAA Chart: 11376 Latitude: 30° 42.5' N ( 30.70830)
USGS Quad: MOBILE Longitude: 88° 2.6' W ( -88.04330)
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.