U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Datums Page Page 1 of 5
PUBLICATION DATE: 05/03/1989
Station ID: 8661437 SUPERCEDED DATE: 04/21/2003
Name: GARDEN CITY PIER, ATLANTIC OCEAN
SOUTH CAROLINA
NOAA Chart: 11535 Latitude: 33° 34.5' N
USGS Quad: MYRTLE BEACH Longitude: 78° 59.8' W
To reach the tidal bench marks from U.S Highway 17 in Myrtle Beach, proceed
south on U.S. Highway 17 for approximately 9 miles (14 km) to the exit for
Garden City, turn left and proceed east on Atlantic Drive for 1.0 mile (1.6
km) to Ocean Boulevard and the King Fisher Inn. The bench marks are in the inn
parking lot and NE of the inn along Magnolia Avenue between Ocean Boulevard and
Dogwood Drive. The tide gage and staff were on the seaward end of the King
Fisher Inn pier.
T I D A L B E N C H M A R K S
PRIMARY BENCH MARK STAMPING: GCP NO 3 1975
MONUMENTATION: Survey Disk VM#: 3772
AGENCY: PID#: DD1496
SETTING CLASSIFICATION: Concrete Foundation
The bench mark is set in the concrete foundation of a sewer lift station in the
west corner of the King Fisher Inn parking lot, 76.4 feet (23.3 m) west of the
west corner of the inn, 34.8 feet (10.6 m) ESE of the centerline of Ocean
Boulevard, 10.2 feet (3.1 m) SSE of a fire hydrant, 6.6 feet (2.0 m) NW of the
west corner of a concrete pillar supporting a wooden fence, 1.7 feet (0.5 m)
west of the east corner post of the sewer lift station steel bumper guard, and
at ground level.
BENCH MARK STAMPING: GCP NO 1 1975
MONUMENTATION: Survey Disk VM#: 3771
AGENCY: PID:
SETTING CLASSIFICATION: Concrete Foundation
The bench mark is set in the concrete foundation of an electrical transformer at
the landward end of the King Fisher Inn pier, 7.6 feet (2.3 m) SW of the pier
entrance ramp, 6.8 feet (2.1 m) NW of the NW wall of the pier restaurant, 0.6
foot (0.2 m) east of the west corner of the foundation, and 1.5 feet (0.5 m)
above ground level.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 2 of 5
PUBLICATION DATE: 05/03/1989
Station ID: 8661437 SUPERCEDED DATE: 04/21/2003
Name: GARDEN CITY PIER, ATLANTIC OCEAN
SOUTH CAROLINA
NOAA Chart: 11535 Latitude: 33° 34.5' N
USGS Quad: MYRTLE BEACH Longitude: 78° 59.8' W
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: GCP NO 4 1975
MONUMENTATION: Survey Disk VM#: 3773
AGENCY: PID#: DD1495
SETTING CLASSIFICATION: Concrete Foundation
The bench mark is set in the north corner of the concrete foundation of the
highrise portion of the King Fisher Inn, 88 feet (27 m) SW of the sea wall at
the NE end of the inn parking lot, 82 feet (25 m) SE of the centerline of Ocean
Boulevard, 0.5 foot (0.2 m) north of the north corner of the inn, and at ground
level.
BENCH MARK STAMPING: 1437 G 1982
MONUMENTATION: Survey Disk VM#: 3774
AGENCY: PID:
SETTING CLASSIFICATION: Stainless Steel Rod
The bench mark is in the NW corner of the intersection of Ocean Boulevard and
Magnolia Avenue, 79.8 feet (24.3 m) ENE of utility pole #181B, 67.0 feet
(20.4 m) NE of the east corner of the Ocean View Motel retaining wall, 34.7 feet
(10.6 m) NW of the centerline of Ocean Boulevard, 32.0 feet (9.8 m) NE of the
centerline of Magnolia Avenue, and 6.2 feet (1.9 m) NW of utility pole #3310.
The bench mark is at ground level, crimped to a stainless steel rod driven 27
feet (8 m) to refusal, and encased in a 5-inch PVC pipe and concrete kickblock.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 3 of 5
PUBLICATION DATE: 05/03/1989
Station ID: 8661437 SUPERCEDED DATE: 04/21/2003
Name: GARDEN CITY PIER, ATLANTIC OCEAN
SOUTH CAROLINA
NOAA Chart: 11535 Latitude: 33° 34.5' N
USGS Quad: MYRTLE BEACH Longitude: 78° 59.8' W
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 1437 H 1982
MONUMENTATION: Survey Disk VM#: 3775
AGENCY: PID#: DD1513
SETTING CLASSIFICATION: Stainless Steel Rod
The bench mark is in the east corner of the intersection of Dogwood Drive and
Magnolia Avenue, 97.9 feet (29.8 m) west of the west corner of a two-story
cinder block house, 29.9 feet (9.1 m) ESE of the centerline of Dogwood Drive,
20.8 feet (6.3 m) SSW of utility pole #69077, and 16.4 feet (5.0 m) NNE of the
centerline of Magnolia Avenue. The bench mark is 0.2 foot (0.1 m) below
ground level, crimped to a stainless steel rod driven 27 feet (8 m) to refusal,
and encased in a 5-inch PVC pipe and concrete kickblock.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 4 of 5
PUBLICATION DATE: 05/03/1989
Station ID: 8661437 SUPERCEDED DATE: 04/21/2003
Name: GARDEN CITY PIER, ATLANTIC OCEAN
SOUTH CAROLINA
NOAA Chart: 11535 Latitude: 33° 34.5' N
USGS Quad: MYRTLE BEACH Longitude: 78° 59.8' W
T I D A L D A T U M S
Tidal datums at GARDEN CITY PIER, ATLANTIC OCEAN based on:
LENGTH OF SERIES: 22 MONTHS
TIME PERIOD: MARCH 1975 - DECEMBER 1976
TIDAL EPOCH: 1960-1978
CONTROL TIDE STATION: 8665530 CHARLESTON
Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in FEET:
HIGHEST OBSERVED WATER LEVEL (11/21/1976) = 7.62
MEAN HIGHER HIGH WATER MHHW = 5.64
MEAN HIGH WATER MHW = 5.27
MEAN TIDE LEVEL MTL = 2.74
MEAN LOW WATER MLW = 0.20
MEAN LOWER LOW WATER MLLW = 0.00
LOWEST OBSERVED WATER LEVEL (03/17/1976) = -3.15
North American Vertical Datum (NAVD88)
Bench Mark Elevation Information In FEET above:
Stamping or Designation MLLW MHW
GCP NO 3 1975 9.40 4.13
GCP NO 1 1975 13.49 8.22
GCP NO 4 1975 11.22 5.95
1437 G 1982 9.01 3.74
1437 H 1982 6.73 1.46
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 5 of 5
PUBLICATION DATE: 05/03/1989
Station ID: 8661437 SUPERCEDED DATE: 04/21/2003
Name: GARDEN CITY PIER, ATLANTIC OCEAN
SOUTH CAROLINA
NOAA Chart: 11535 Latitude: 33° 34.5' N
USGS Quad: MYRTLE BEACH Longitude: 78° 59.8' 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.