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National Ocean Service
Datums Page Page 1 of 5
Station ID: 8677832 PUBLICATION DATE: 09/26/2003
Name: JEKYLL ISLAND MARINA, JEKYLL CREEK
GA
NOAA Chart: 11504 Latitude: 31° 3.4' N ( 31.05670)
USGS Quad: JEKYLL ISLAND Longitude: 81° 25.4' W ( -81.42330)
To reach the tidal bench marks from Brunswick, proceed south on U.S. Highway 17
across the Sidney Lanier Bridge to Jekyll Island Causeway, then turn left (east)
onto Route 520 (Jekyll Island Causeway) and travel across the causeway to Jekyll
Island, turn left (north) onto Riverview Drive and contine to Jekyll Island
Marina. The bench marks are near the end of the pier and in the adjacent
seawall at Jekyll Island Marina. The tide station were located on the pier.
T I D A L B E N C H M A R K S
PRIMARY BENCH MARK STAMPING: 7832 A 1980
DESIGNATION: 867 7832 A TIDAL
MONUMENTATION: Tidal Station disk VM#: 4936
AGENCY: National Ocean Survey (NOS) IDB PID#:
SETTING CLASSIFICATION: Concrete sea wall OPUS PID:
LATITUDE: 31° 3.4' N ( 31.05670) LONGITUDE: 81° 25.4' W ( -81.42330)
The primary bench mark is a disk set flush in the center of the east-west
running concrete sea wall which intersects a north-south running sea wall, 39 m
(128 ft) north of the pier, and 5 m (17 ft) east of the north-south sea wall.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 2 of 5
Station ID: 8677832 PUBLICATION DATE: 09/26/2003
Name: JEKYLL ISLAND MARINA, JEKYLL CREEK
GA
NOAA Chart: 11504 Latitude: 31° 3.4' N ( 31.05670)
USGS Quad: JEKYLL ISLAND Longitude: 81° 25.4' W ( -81.42330)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 7832 B 1980
DESIGNATION: 867 7832 B TIDAL
MONUMENTATION: Tidal Station disk VM#: 4937
AGENCY: National Ocean Survey (NOS) IDB PID#:
SETTING CLASSIFICATION: Concrete water fountain foundation OPUS PID:
LATITUDE: 31° 3.4' N ( 31.05670) LONGITUDE: 81° 25.4' W ( -81.42330)
The bench mark is a disk set flush in the NE corner of a 1.04 m (3.4 ft) square
concrete water fountain foundation located adjacent to a sidewalk running
north-south from the marina parking lot (by the bathhouse) to Pier Street, 42.06
m (138.0 ft) south of bench mark 7832 A 1980, 10.67 m (35.0 ft) east of the
north-south sea wall, and 3.0 m (10 ft) south of the centerline of Pier Street.
BENCH MARK STAMPING: 7832 C 1980
DESIGNATION: 867 7832 C TIDAL
MONUMENTATION: Tidal Station disk VM#: 4938
AGENCY: National Ocean Survey (NOS) IDB PID#:
SETTING CLASSIFICATION: Concrete step OPUS PID:
LATITUDE: 31° 3.4' N ( 31.05670) LONGITUDE: 81° 25.4' W ( -81.42330)
The bench mark is a disk set in the NE corner of a 0.98 m (3.2 ft) square
concrete step leading to the entrance door of the women's lavatory located at
the NW corner of the bathhouse building, 13 m (43 ft) south of the end of the
pier, and 3 m (11 ft) east of the sea wall.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 3 of 5
Station ID: 8677832 PUBLICATION DATE: 09/26/2003
Name: JEKYLL ISLAND MARINA, JEKYLL CREEK
GA
NOAA Chart: 11504 Latitude: 31° 3.4' N ( 31.05670)
USGS Quad: JEKYLL ISLAND Longitude: 81° 25.4' W ( -81.42330)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 7832 D 1980
DESIGNATION: 867 7832 D TIDAL
MONUMENTATION: Tidal Station disk VM#: 4939
AGENCY: National Ocean Survey (NOS) IDB PID#:
SETTING CLASSIFICATION: Concrete sea wall OPUS PID#: BBCD02
LATITUDE: 31° 3.4' N ( 31.05670) LONGITUDE: 81° 25.4' W ( -81.42330)
The bench mark is a disk set flush in the concrete sea wall, 61 m (200 ft) south
of the south edge of the pier, 47.85 m (157.0 ft) south of bench mark 7832 C
1980, and 0.24 m (0.8 ft) east of the west edge of the sea wall.
BENCH MARK STAMPING: NO. 1 49
DESIGNATION: 867 7832 TIDAL 1
MONUMENTATION: Survey disk VM#: 4940
AGENCY: US Army Corps of Engineers (USE) IDB PID#:
SETTING CLASSIFICATION: Concrete sea wall OPUS PID:
LATITUDE: 31° 3.4' N ( 31.05670) LONGITUDE: 81° 25.4' W ( -81.42330)
The bench mark is a disk set flush in a concrete sea wall located just north of
the end of the pier, and 38.71 m (128 ft) SSW of bench mark 7832 A 1980.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 4 of 5
Station ID: 8677832 PUBLICATION DATE: 09/26/2003
Name: JEKYLL ISLAND MARINA, JEKYLL CREEK
GA
NOAA Chart: 11504 Latitude: 31° 3.4' N ( 31.05670)
USGS Quad: JEKYLL ISLAND Longitude: 81° 25.4' W ( -81.42330)
T I D A L D A T U M S
Tidal datums at JEKYLL ISLAND MARINA, JEKYLL CREEK based on:
LENGTH OF SERIES: 1 MONTH
TIME PERIOD: 5/26/1980 - 6/26/1980
TIDAL EPOCH: 1983-2001
CONTROL TIDE STATION: 8670870 FORT PULASKI, SAVANNAH RIVER
Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in METERS:
MEAN HIGHER HIGH WATER MHHW = 2.252
MEAN HIGH WATER MHW = 2.146
MEAN SEA LEVEL MSL = 1.141
MEAN TIDE LEVEL MTL = 1.106
MEAN LOW WATER MLW = 0.066
MEAN LOWER LOW WATER MLLW = 0.000
North American Vertical Datum (NAVD88)
Bench Mark Elevation Information In METERS above:
Stamping or Designation MLLW MHW
7832 A 1980 3.906 1.760
7832 B 1980 4.163 2.017
7832 C 1980 4.101 1.955
7832 D 1980 3.903 1.757
NO. 1 49 3.903 1.757
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 5 of 5
Station ID: 8677832 PUBLICATION DATE: 09/26/2003
Name: JEKYLL ISLAND MARINA, JEKYLL CREEK
GA
NOAA Chart: 11504 Latitude: 31° 3.4' N ( 31.05670)
USGS Quad: JEKYLL ISLAND Longitude: 81° 25.4' W ( -81.42330)
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.