U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Datums Page Page 1 of 4
PUBLICATION DATE: 06/03/1987
Station ID: 8670678 SUPERCEDED DATE: 04/21/2003
Name: FORT JACKSON, SAVANNAH RIVER
GEORGIA
NOAA Chart: 11512 Latitude: 32° 4.9' N
USGS Quad: SAVANNAH Longitude: 81° 2.2' W
To reach the tidal bench marks from the intersection of Bull and East Bay
Streets in downtown Savannah, proceed east on East Bay Street for 0.9 mile (1.4
m) until it becomes General MacIntosh Boulevard, continue on General MacIntosh
Boulevard for 1.2 miles (1.9 km) to the intersection of President Street
Extension (US Highway 80), turn left onto US Highway 80 for 1.1 miles (1.8 km)
to Woodcock Road, turn left (north) onto Woodcock Road for 0.3 mile (0.5 km) to
the entrance gate of Fort Jackson Park, turn right onto the Fort Jackson access
road 0.8 mile (1.3 km) to the parking area. The bench marks are located north
of the parking area. The tide gage and staff were located on the pier at the
north end of the fort.
T I D A L B E N C H M A R K S
PRIMARY BENCH MARK STAMPING: 0678 A 1979
MONUMENTATION: Survey Disk VM#: 4720
AGENCY: PID:
SETTING CLASSIFICATION: Unspecified Rod
The bench mark is located near a flagpole, 272 feet (83 m) north of Bench Mark
0678 B 1979, 97.8 feet (29.8 m) SSE of the corner of a brick seawall, 57.7 feet
(17.6 m) SW of a wooden bridge over the moat leading into Fort Jackson, 22.0
feet (6.7 m) SSW of confederate cannon #32, and 1.5 feet (0.5 m) NE of the
flagpole. The bench mark is 0.1 foot (0.03 m) below ground level, crimped to an
unspecified rod driven 48 feet (15 m) to refusal, and encased in 4-inch PVC pipe
and concrete kickblock.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 2 of 4
PUBLICATION DATE: 06/03/1987
Station ID: 8670678 SUPERCEDED DATE: 04/21/2003
Name: FORT JACKSON, SAVANNAH RIVER
GEORGIA
NOAA Chart: 11512 Latitude: 32° 4.9' N
USGS Quad: SAVANNAH Longitude: 81° 2.2' W
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 0678 B 1979
MONUMENTATION: Survey Disk VM#: 4721
AGENCY: PID:
SETTING CLASSIFICATION: Unspecified Rod
The bench mark is located near the SE corner of the parking area, 244.0 feet
(74.4 m) east of Bench Mark 0678 C 1979, 57.0 feet (17.4 m) north of the NE
corner of a wooden structure, 18.0 feet (5.5 m) SW of a lone tree, and 1.4 feet
(0.4 m) SE of the white corner post of the chain fence at the parking area. The
bench mark is 0.2 foot (0.1 m) below ground level, crimped to an unspecified rod
driven 48 feet (15 m) to refusal, and encased in 4-inch PVC pipe and concrete
kickblock.
BENCH MARK STAMPING: 0678 C 1979
MONUMENTATION: Survey Disk VM#: 4722
AGENCY: PID:
SETTING CLASSIFICATION: Unspecified Rod
The bench mark is 333.4 feet (101.6 m) SW of Bench Mark 0678 A 1979, 77.1 feet
(23.5 m) north of the centerline of the paved road leading to the parking area,
6.9 feet (2.1 m) NE of a chainlink fence, and 1.6 feet (0.5 m) ESE of a utility
pole with witness sign. The bench mark is 0.1 foot (0.03 m) below ground level,
crimped to an unspecified rod driven 48 feet (15 m) 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 3 of 4
PUBLICATION DATE: 06/03/1987
Station ID: 8670678 SUPERCEDED DATE: 04/21/2003
Name: FORT JACKSON, SAVANNAH RIVER
GEORGIA
NOAA Chart: 11512 Latitude: 32° 4.9' N
USGS Quad: SAVANNAH Longitude: 81° 2.2' W
T I D A L D A T U M S
Tidal datums at FORT JACKSON, SAVANNAH RIVER based on:
LENGTH OF SERIES: 7 MONTHS
TIME PERIOD: OCTOBER 1979-MAY 1980
TIDAL EPOCH: 1960-1978
CONTROL TIDE STATION: 8670870 FORT PULASKI
Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in FEET:
HIGHEST OBSERVED WATER LEVEL (05/16/1980) = 10.07
MEAN HIGHER HIGH WATER MHHW = 8.15
MEAN HIGH WATER MHW = 7.80
MEAN TIDE LEVEL MTL = 4.02
MEAN LOW WATER MLW = 0.24
MEAN LOWER LOW WATER MLLW = 0.00
LOWEST OBSERVED WATER LEVEL (04/15/1980) = -2.45
Bench Mark Elevation Information In FEET above:
Stamping or Designation MLLW MHW
0678 A 1979 11.06 3.26
0678 B 1979 14.93 7.13
0678 C 1979 13.10 5.30
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 4 of 4
PUBLICATION DATE: 06/03/1987
Station ID: 8670678 SUPERCEDED DATE: 04/21/2003
Name: FORT JACKSON, SAVANNAH RIVER
GEORGIA
NOAA Chart: 11512 Latitude: 32° 4.9' N
USGS Quad: SAVANNAH Longitude: 81° 2.2' 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.