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Datums Page Page 1 of 8
Station ID: 8670870 PUBLICATION DATE: 09/12/2017
Name: FORT PULASKI, SAVANNAH RIVER
GA
NOAA Chart: 11513 Latitude: 32° 2.2' N ( 32.03670)
USGS Quad: FORT PULASKI Longitude: 80° 54.1' W ( -80.90170)
To reach the tidal bench marks from the intersection of State Highway 204 in
Savannah, go easterly 21.1 km (13.1 mi) along U.S. Highway 80, thence 1.2 km
(0.7 mi) northerly along the Fort Pulaski National Monument entrance road,
thence 0.8 km (0.5 mi) westerly along the Tybee Coast Guard Station entrance
road, thence 0.1 km (0.1 mi) northerly along the Savannah Bar Pilot House
entrance road. The bench marks are located along the entrance road and in the
vicinity of the Savannah Bar Pilot House. The gage is located in a NOS tide
house on the Pilots Dock located behind the Savannah Bar Pilot House.
T I D A L B E N C H M A R K S
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 2 of 8
Station ID: 8670870 PUBLICATION DATE: 09/12/2017
Name: FORT PULASKI, SAVANNAH RIVER
GA
NOAA Chart: 11513 Latitude: 32° 2.2' N ( 32.03670)
USGS Quad: FORT PULASKI Longitude: 80° 54.1' W ( -80.90170)
T I D A L B E N C H M A R K S
PRIMARY BENCH MARK STAMPING: P 323 1974
DESIGNATION: P 323
MONUMENTATION: Vertical Control disk VM#: 632
AGENCY: National Geodetic Survey (NGS) IDB PID#: CK0694
SETTING CLASSIFICATION: Copper-clad steel rod OPUS PID:
LATITUDE: 32° 2.0' N ( 32.03331) LONGITUDE: 80° 54.1' W ( -80.90169)
The primary bench mark is a disk located 23.41 m (76.8 ft) SW of the SW corner
of the Savannah Bar Pilots house, 10.10 m (33.1 ft) south of and level with the
extended center of a driveway, 4.30 m (14.1 ft) west of a utility pole with 2
guy wires and a transformer, and 1.19 m (3.9 ft) east of a witness post. The
bench mark is at ground level, crimped to a copper-coated steel rod driven 17.1
m (56 ft) to refusal, and encased in a 4-inch PVC pipe and concrete kickblock.
BENCH MARK STAMPING: 1
DESIGNATION: 867 0870 TIDAL 1
MONUMENTATION: Tidal Station disk VM#: 626
AGENCY: US Coast and Geodetic Survey
(USC&GS) IDB PID#: CK0692
SETTING CLASSIFICATION: Concrete bridge OPUS PID#: CK0692
LATITUDE: 32° 1.4' N ( 32.02331) LONGITUDE: 80° 53.8' W ( -80.89669)
The bench mark is a disk set in the north end of the east concrete wingwall of a
bridge spanning south channel, 10.60 m (34.8 ft) south of the north end of the
east bridge rail, 3.30 m ((10.8 ft) east of the road centerline, and 0.20 m (0.7
ft) above the level of the road.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 3 of 8
Station ID: 8670870 PUBLICATION DATE: 09/12/2017
Name: FORT PULASKI, SAVANNAH RIVER
GA
NOAA Chart: 11513 Latitude: 32° 2.2' N ( 32.03670)
USGS Quad: FORT PULASKI Longitude: 80° 54.1' W ( -80.90170)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: NO 1 1949
DESIGNATION: 867 0870 TIDAL 1
MONUMENTATION: Tidal Station disk VM#: 629
AGENCY: US Coast and Geodetic Survey
(USC&GS) IDB PID#: CK0692
SETTING CLASSIFICATION: Concrete bridge OPUS PID:
LATITUDE: 32° 1.4' N ( 32.02331) LONGITUDE: 80° 53.8' W ( -80.89669)
The bench mark is a disk set at the north end of the east concrete wingwall of a
bridge spanning the South Channel of the Savannah River, along the entrance road
to Fort Pulaski National Monument, 10.61 m (34.8 ft) south of the north end of
the east bridge rail, 3.29 m (10.8 ft) east of the centerline of the bridge, and
0.21 m (0.7 ft) above the level of the road.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 4 of 8
Station ID: 8670870 PUBLICATION DATE: 09/12/2017
Name: FORT PULASKI, SAVANNAH RIVER
GA
NOAA Chart: 11513 Latitude: 32° 2.2' N ( 32.03670)
USGS Quad: FORT PULASKI Longitude: 80° 54.1' W ( -80.90170)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: N 323 1974
DESIGNATION: N 323
MONUMENTATION: Vertical Control disk VM#: 631
AGENCY: National Geodetic Survey (NGS) IDB PID#: CK0693
SETTING CLASSIFICATION: Copper-clad steel rod OPUS PID:
LATITUDE: 32° 2.0' N ( 32.03331) LONGITUDE: 80° 54.1' W ( -80.90169)
The bench mark is a disk located near the Fort Pulaski Maintenance Shop along
the Tybee Coast Guard Station entrance road, 38.19 m (125.3 ft) south of and
level with the center of the road, 15.00 m (49.2 ft) SSW of the SW corner of the
Fort Pulaski Maintenance Shop, 4.69 m (15.4 ft) north of a witness post, and
0.91 m (3.0 ft) west of the east edge of a foundation for a radio tower. The
bench mark is at ground level, crimped to a copper-coated steel rod driven 19.5
m (64 ft) to refusal, and encased in a 4-inch PVC pipe and concrete kickblock.
BENCH MARK STAMPING: 0870 M 2001
DESIGNATION: 867 0870 M TIDAL
MONUMENTATION: Tidal Station disk VM#: 16513
AGENCY: National Ocean Service (NOS) IDB PID#: DG4147
SETTING CLASSIFICATION: Concrete foundation OPUS PID:
LATITUDE: 32° 2.2' N ( 32.03669) LONGITUDE: 80° 54.1' W ( -80.90169)
The bench mark is a disk set flush in old guy wire concrete foundation near the
north part of the picnic area along the Tybee Coast Guard Station entrance road,
99.20 m (325.5 ft) SE of a power pole having no number and in line with a Coast
Guard radio tower, 62.85 m (206.2 ft) SW of the centerline of the road leading
to the Tybee Coast Guard Station, and 31.14 m (102.2 ft) east of the east corner
of a white cinderblock pump house.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 5 of 8
Station ID: 8670870 PUBLICATION DATE: 09/12/2017
Name: FORT PULASKI, SAVANNAH RIVER
GA
NOAA Chart: 11513 Latitude: 32° 2.2' N ( 32.03670)
USGS Quad: FORT PULASKI Longitude: 80° 54.1' W ( -80.90170)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: BARPILOT 2000
DESIGNATION: BAR PILOT
MONUMENTATION: Reference Mark disk VM#: 17402
AGENCY: South Carolina Geodetic Survey (SCGS) IDB PID#: AI8598
SETTING CLASSIFICATION: Concrete pier OPUS PID:
LATITUDE: 32° 2.1' N ( 32.03500) LONGITUDE: 80° 54.2' W ( -80.90331)
The bench mark is set flush in the concrete pier deck located on the Bar Pilots
pier right before the turn in the dock, 60.95 m (200.0 ft) north of the north
side of the pilot's house, 12.75 m (41.8 ft) south of the east corner of the
dock, and 1.01 m (3.3 ft) west of the east edge of the dock.
BENCH MARK STAMPING: 0870 N 2015
DESIGNATION: 867 0870 N
MONUMENTATION: Metal Rod VM#: 21841
AGENCY: NOS IDB PID#:
SETTING CLASSIFICATION: Stainless steel rod OPUS PID:
LATITUDE: 32° 2.0' N ( 32.03253) LONGITUDE: 80° 54.1' W ( -80.90183)
The bench mark is a stainless steel rod driven to refusal in a 5 inch PVC sleeve
and aluminum cap set in concrete kick plate, 130.20 m (427.2 ft) northwest of
bench mark 867 0870 P, 62.27 m (204.3 ft) east of east corner of maintenance
building, 31 m (101
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 6 of 8
Station ID: 8670870 PUBLICATION DATE: 09/12/2017
Name: FORT PULASKI, SAVANNAH RIVER
GA
NOAA Chart: 11513 Latitude: 32° 2.2' N ( 32.03670)
USGS Quad: FORT PULASKI Longitude: 80° 54.1' W ( -80.90170)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 0870 P 2015
DESIGNATION: 867 0870 P
MONUMENTATION: Metal Rod VM#: 21842
AGENCY: NOS IDB PID#:
SETTING CLASSIFICATION: Stainless steel rod OPUS PID:
LATITUDE: 32° 1.9' N ( 32.03192) LONGITUDE: 80° 54.0' W ( -80.90064)
The bench mark is a stainless steel rod driven to refusal inside a 5 inch (13
cm) PVC sleeve set in a concrete kick block with an aluminum cap, 130.20 m
(427.2 ft) southeast of bench mark 867 0870 N, 98.86 m (324.3 ft) north of
northwest corner of a pavilion, 19.17 m (62.9 ft) east of a speed limit sign,
8.56 m (28.1 ft) north-northeast of center line of a road running east/west
passing in front of maintenance building, 3.58 m (11.7 ft) south of a witness
post.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 7 of 8
Station ID: 8670870 PUBLICATION DATE: 09/12/2017
Name: FORT PULASKI, SAVANNAH RIVER
GA
NOAA Chart: 11513 Latitude: 32° 2.2' N ( 32.03670)
USGS Quad: FORT PULASKI Longitude: 80° 54.1' W ( -80.90170)
T I D A L D A T U M S
Tidal datums at FORT PULASKI, SAVANNAH RIVER based on:
LENGTH OF SERIES: 19 YEARS
TIME PERIOD: January 1983 - December 2001
TIDAL EPOCH: 1983-2001
CONTROL TIDE STATION:
Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in METERS:
HIGHEST OBSERVED WATER LEVEL (10/08/2016) = 3.794
MEAN HIGHER HIGH WATER MHHW = 2.287
MEAN HIGH WATER MHW = 2.174
North American Vertical Datum NAVD88 = 1.235
MEAN SEA LEVEL MSL = 1.165
MEAN TIDE LEVEL MTL = 1.119
MEAN LOW WATER MLW = 0.066
MEAN LOWER LOW WATER MLLW = 0.000
LOWEST OBSERVED WATER LEVEL (03/20/1936) = -1.401
North American Vertical Datum (NAVD88)
Bench Mark Elevation Information In METERS above:
Stamping or Designation MLLW MHW
P 323 1974 3.690 1.517
1 3.869 1.695
NO 1 1949 3.873 1.699
N 323 1974 3.017 0.844
0870 M 2001 3.350 1.177
BARPILOT 2000 4.068 1.895
0870 N 2015 3.357 1.183
0870 P 2015 2.604 0.431
Foot Notes:
Bench marks 0870 N 2015, 0870 P 2015, and 1 are based on one differential
leveling connection and do not meet the quality control standards of the NOS.
Therefore, caution should be used when deriving elevations for these marks.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 8 of 8
Station ID: 8670870 PUBLICATION DATE: 09/12/2017
Name: FORT PULASKI, SAVANNAH RIVER
GA
NOAA Chart: 11513 Latitude: 32° 2.2' N ( 32.03670)
USGS Quad: FORT PULASKI Longitude: 80° 54.1' W ( -80.90170)
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.