U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Datums Page Page 1 of 4
Station ID: 8679945 PUBLICATION DATE: 05/19/2003
Name: BEACH CREEK
GA
NOAA Chart: 11503 Latitude: 30° 43.6' N ( 30.72670)
USGS Quad: FERNANDINA BEACH Longitude: 81° 28.6' W ( -81.47670)
To reach the bench marks from the offshore end of North Jetty at St Marys
Entrance by boat, proceed WNW for about 8 km (5 statute mi) to red buoy #36 at
the entrance to Beach Creek. The bench marks are on the west side of Cumberland
Island along the shore, about 244 m (800 ft) south of Beach Creek. The tide
gage and staff were at the Beach Creek entrance.
T I D A L B E N C H M A R K S
PRIMARY BENCH MARK STAMPING: BM 1 1987
DESIGNATION: 867 9945 BM 1
MONUMENTATION: Survey disk VM#: 4955
AGENCY: US Army Corps Of Engineers (USE) IDB PID#:
SETTING CLASSIFICATION: Concrete filled PVC pipe OPUS PID:
LATITUDE: 30° 43.6' N ( 30.72670) LONGITUDE: 81° 28.6' W ( -81.47670)
The primary bench mark is a disk set in the top of an 8-inch PVC pipe filled
with concrete, 20 m (64 ft) SE of bench mark LEE ST 1984, and 0.3 m (1 ft) above
the ground.
BENCH MARK STAMPING: LEE ST 1984
DESIGNATION: 867 9945 LEE ST
MONUMENTATION: Survey disk VM#: 4954
AGENCY: US Army Corps Of Engineers (USE) IDB PID#:
SETTING CLASSIFICATION: Concrete filled PVC pipe OPUS PID:
LATITUDE: 30° 43.6' N ( 30.72670) LONGITUDE: 81° 28.6' W ( -81.47670)
The bench mark is a disk set in the top of a 10-inch PVC pipe filled with
concrete, about 3.1 km (1.9 mi) NW of the southern end of the island, 1.1 km
(0.7 mi) west of the west end of North Jetty and 244 m (800 ft) south of the
mouth of Beach Creek on the west side of Cumberland Island.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 2 of 4
Station ID: 8679945 PUBLICATION DATE: 05/19/2003
Name: BEACH CREEK
GA
NOAA Chart: 11503 Latitude: 30° 43.6' N ( 30.72670)
USGS Quad: FERNANDINA BEACH Longitude: 81° 28.6' W ( -81.47670)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: BM 2 1987
DESIGNATION: 867 9945 BM 2
MONUMENTATION: Survey disk VM#: 4956
AGENCY: US Army Corps Of Engineers (USE) IDB PID#:
SETTING CLASSIFICATION: Concrete filled PVC pipe OPUS PID:
LATITUDE: 30° 43.6' N ( 30.72670) LONGITUDE: 81° 28.6' W ( -81.47670)
The bench mark is a disk set in the top of an 8-inch PVC pipe filled with
concrete, 12 m (40 ft) east of bench mark LEE ST 1984, 15 m (50 ft) NW of bench
mark BM 1 1987and 0.3 m (1 ft) above the ground.
BENCH MARK STAMPING: BM 3 1987
DESIGNATION: 867 9945 BM 3
MONUMENTATION: Survey disk VM#: 4957
AGENCY: US Army Corps of Engineers (USE) IDB PID#:
SETTING CLASSIFICATION: PVC pipe filled with concrete OPUS PID:
LATITUDE: 30° 43.6' N ( 30.72670) LONGITUDE: 81° 28.6' W ( -81.47670)
The bench mark is a disk set in the top of an 8-inch PVC pipe filled with
concrete, 15 m (50 ft) north of Bench Mark BM 2 1987 and 0.3 m (1 ft) above the
ground.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 3 of 4
Station ID: 8679945 PUBLICATION DATE: 05/19/2003
Name: BEACH CREEK
GA
NOAA Chart: 11503 Latitude: 30° 43.6' N ( 30.72670)
USGS Quad: FERNANDINA BEACH Longitude: 81° 28.6' W ( -81.47670)
T I D A L D A T U M S
Tidal datums at BEACH CREEK based on:
LENGTH OF SERIES: 1 MONTH
TIME PERIOD: February 1987 - February 1987
TIDAL EPOCH: 1983-2001
CONTROL TIDE STATION: 8720030 FERNANDINA BEACH, AMELIA RIVER
Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in METERS:
MEAN HIGHER HIGH WATER MHHW = 1.972
MEAN HIGH WATER MHW = 1.860
MEAN SEA LEVEL MSL = 0.978
MEAN TIDE LEVEL MTL = 0.958
MEAN LOW WATER MLW = 0.056
MEAN LOWER LOW WATER MLLW = 0.000
North American Vertical Datum (NAVD88)
Bench Mark Elevation Information In METERS above:
Stamping or Designation MLLW MHW
BM 1 1987 3.053 1.193
LEE ST 1984 2.374 0.514
BM 2 1987 3.126 1.266
BM 3 1987 3.346 1.486
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 4 of 4
Station ID: 8679945 PUBLICATION DATE: 05/19/2003
Name: BEACH CREEK
GA
NOAA Chart: 11503 Latitude: 30° 43.6' N ( 30.72670)
USGS Quad: FERNANDINA BEACH Longitude: 81° 28.6' W ( -81.47670)
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.