U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
Datums Page                                                        Page  1 of  5

                                                   PUBLICATION DATE:  09/16/1988
Station ID: 8661529                                SUPERCEDED DATE:   04/21/2003
Name:       CAPTAIN ALEXS MARINA, MURRELLS INLET, PARSONAGE CR
            SOUTH CAROLINA
NOAA Chart: 11535                                  Latitude:         33° 33.1' N
USGS Quad:  BROOKGREEN                             Longitude:        79°  2.2' W


To reach the tidal bench marks from the intersection of U.S. Highway 17 and
State Highway 707 in Murrells Inlet, proceed east on State Highway 707 for 0.4
mile (0.6 km) to U.S. Highway 17 (business), then south on U.S. Highway 17
(business) for 0.7 mile (1.1 km) to Captain Alexs Marina.  The bench marks are
along U.S. Highway 17 (business) and in the vicinity of Captain Alexs Marina. 
The tide gage and staff were on the NE side of the dock.


                         T I D A L   B E N C H   M A R K S


                 PRIMARY BENCH MARK STAMPING:  CA NO 4 1975

MONUMENTATION:           Survey Disk                               VM#:     3783
AGENCY:                                                            PID#:  DD1479
SETTING CLASSIFICATION:  Copper-clad Steel Rod


The bench mark is at the intersection of U.S. Highway 17 (business) and State
Road S-22-188, 0.2 mile (0.3 km) SW of Bench Mark NO 3 1975, 80.4 feet (24.5 m)
SW of a lone cedar tree in the front yard of the Belin Methodist Educational
Building, 33.5 feet (10.2 m) NNW of the centerline of the U.S. Highway 17
(business), 29.5 feet (9.0 m) ENE of the centerline of State Road S-22-188, and
14.4 feet (4.4 m) south of utility pole #A-L1A.  The bench mark is 0.2 foot (0.1
m) below ground level, crimped to a copper-clad steel rod driven 40 feet (12 m)
to refusal, and encased in a PVC pipe and concrete kickblock.



                         BENCH MARK STAMPING:  CA NO 3 1975

MONUMENTATION:           Survey Disk                               VM#:     3782
AGENCY:                                                            PID#:  DD1480
SETTING CLASSIFICATION:  Copper-clad Steel Rod


The bench mark is at the intersection of U.S. Highway 17 (business) and State
Road S-22-559, 34.2 feet (10.4 m) NW of the centerline of U.S. Highway 17
(business), 29.3 feet (8.9 m) NE of State Road S-22-559, 13.1 feet (4.0 m) ESE
of utility pole #17683, 7.7 feet (2.3 m) ESE of the south corner of a fence for
the Bay Harbor property, and 3.3 feet (1.0 m) SSE of a witness post with sign. 
The bench mark is 0.1 foot (0.03 m) below ground level, crimped to a copper-clad
steel rod driven 40 feet (12 m) to refusal, and encased in a PVC pipe and
concrete kickblock.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  2 of  5

                                                   PUBLICATION DATE:  09/16/1988
Station ID: 8661529                                SUPERCEDED DATE:   04/21/2003
Name:       CAPTAIN ALEXS MARINA, MURRELLS INLET, PARSONAGE CR
            SOUTH CAROLINA
NOAA Chart: 11535                                  Latitude:         33° 33.1' N
USGS Quad:  BROOKGREEN                             Longitude:        79°  2.2' W


                         T I D A L   B E N C H   M A R K S


                         BENCH MARK STAMPING:  1529 F 1982

MONUMENTATION:           Survey Disk                               VM#:     3784
AGENCY:                                                            PID#:  DD1482
SETTING CLASSIFICATION:  Stainless Steel Rod


The bench mark is near a utility pole without wires in the west corner of a
gravel parking lot for Anchor Inn, 89.8 feet (27.4 m) NE of utility pole
#39-12A, 85.2 feet (26.0 m) west of the west corner of Anchor Inn, 40.5 feet
(12.3 m) SE of the centerline of U.S. Highway 17 (business), 9.0 feet (2.7 m) NW
of a 2.0-foot (0.6 m) diameter live oak tree, and 3.1 feet (0.9 m) SE of a
witness post with sign.  The bench mark is crimped to a stainless steel rod
driven 35 feet (11 m) to refusal, and encased in a 5-inch PVC pipe and concrete
kickblock.



                         BENCH MARK STAMPING:  1529 G 1982

MONUMENTATION:           Survey Disk                               VM#:     3785
AGENCY:                                                            PID#:  DD1483
SETTING CLASSIFICATION:  Stainless Steel Rod


The bench mark is 0.15 mile (0.24 km) NE of Bench Mark 1529 F 1982, 57.7 feet
(17.6 m) NNE of the centerline of a sand drive leading east to a two story
house, 55.1 feet (16.8 m) east of a manhole cover, 34.3 feet (10.5 m) SE of the
centerline of U.S. Highway 17 (business), 2.8 feet (0.9 m) SE of utility pole
#36 1/2 A, and 0.7 foot (0.2 m) SW of a witness post with sign.  The bench mark
is crimped to a stainless steel rod driven 26 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:  09/16/1988
Station ID: 8661529                                SUPERCEDED DATE:   04/21/2003
Name:       CAPTAIN ALEXS MARINA, MURRELLS INLET, PARSONAGE CR
            SOUTH CAROLINA
NOAA Chart: 11535                                  Latitude:         33° 33.1' N
USGS Quad:  BROOKGREEN                             Longitude:        79°  2.2' W


                         T I D A L   B E N C H   M A R K S


                         BENCH MARK STAMPING:  GAGING STATION

MONUMENTATION:           Survey Disk                               VM#:     3786
AGENCY:                                                            PID#:  DD1481
SETTING CLASSIFICATION:  Concrete Monument


The bench mark is set in the top of a concrete monument between Captain Alexs
Marina and the dock, 200 feet (61 m) SSE of the centerline of U.S. Highway 17
(business), 38.4 feet (11.7 m) NNW of the south corner of a cinder block
retaining wall around three fuel storage tanks, 13.4 feet (4.1 m) WSW of a
2-foot (1 m) diameter oak tree at the east corner of a shed, and 5.1 feet (1.6
m) SSW of the south corner of the shed.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  4 of  5

                                                   PUBLICATION DATE:  09/16/1988
Station ID: 8661529                                SUPERCEDED DATE:   04/21/2003
Name:       CAPTAIN ALEXS MARINA, MURRELLS INLET, PARSONAGE CR
            SOUTH CAROLINA
NOAA Chart: 11535                                  Latitude:         33° 33.1' N
USGS Quad:  BROOKGREEN                             Longitude:        79°  2.2' W


                            T I D A L   D A T U M S 


Tidal datums at CAPTAIN ALEXS MARINA, MURRELLS INLET, PARSONAGE CR based on:

     LENGTH OF SERIES:      1 MONTH
     TIME PERIOD:           DECEMBER 1974
     TIDAL EPOCH:           1960-1978
     CONTROL TIDE STATION:  8661419 GARDEN CITY BRIDGE


Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in FEET:

     HIGHEST OBSERVED WATER LEVEL (11/11/1974)         =   6.59
     MEAN HIGHER HIGH WATER                     MHHW   =   4.86
     MEAN HIGH WATER                            MHW    =   4.47
     MEAN TIDE LEVEL                            MTL    =   2.30
     MEAN LOW WATER                             MLW    =   0.13
     MEAN LOWER LOW WATER                       MLLW   =   0.00
     LOWEST  OBSERVED WATER LEVEL (11/13/1974)         =  -0.72

North American Vertical Datum (NAVD88)

Bench Mark Elevation Information                In FEET above:

     Stamping or Designation                    MLLW        MHW

     CA NO 4 1975                               11.36      6.89
     CA NO 3 1975                               11.23      6.76
     1529 F 1982                                11.07      6.60
     1529 G 1982                                 9.68      5.21
     GAGING STATION                              8.97      4.50


                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  5 of  5

                                                   PUBLICATION DATE:  09/16/1988
Station ID: 8661529                                SUPERCEDED DATE:   04/21/2003
Name:       CAPTAIN ALEXS MARINA, MURRELLS INLET, PARSONAGE CR
            SOUTH CAROLINA
NOAA Chart: 11535                                  Latitude:         33° 33.1' N
USGS Quad:  BROOKGREEN                             Longitude:        79°  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.