The Round Island Lighthouse was built 3 miles
south of Pascagoula, Mississippi in 1833. One of
the oldest structures of its type on the Gulf Coast,
the 44 foot tall abandoned lighthouse has always
had a problem with vandalism, but now erosion
threatens to undermine the tower. In 1985 the City
of Pascagoula assumed ownership of the lighthouse
and pursued efforts to preserve this historic
landmark. In 1987, 38 volunteer sailors from the
USS Wisconsin stacked 23 tons of cement bags and
14 tons of sand around the lighthouse, but by 1989
this had all washed away. In 1990, an area 500 feet
by 30 feet west of the lighthouse was dredged six
feet below mean tide and the dirt was placed around the lighthouse and stabilized with 500
pounds of limestone rip rap which was covered with vegetation. However, the lighthouse
continues to be threatened by erosion. In January of 1997, Lighthouse Digest placed the
lighthouse on it's Doomsday List.
This latest effort is to build a breakwater of concrete rubble to stop the erosion. Mississippi Gulf Fishing Banks, Inc. (MGFB) is a non-profit organization experienced in building fishing reefs using concrete rubble. MGFB constructed the breakwater during the Summer of 1997 utilizing Tidelands Funds and it's contractors, Borries Construction and King Marine Services. MGFB contracts King Marine on an annual basis to provide a spotter boat and supervise all of it's reef construction efforts throughout the year. Borries provided the Tug/Barge and loading/unloading of the concrete rubble for this project. The geographical placement of the breakwater was detailed by a Corp of Engineers permit prepared by Compton Engineering of Pascagoula.
The purpose of this report is to show the end results of the construction efforts for use by the
Engineer in determining whether or not the finished breakwater meets with his intentions and if
further measures are needed to make the breakwater more effective.
The DGPS Screen image to the left shows
the location of the Breakwater in relation
to the Lighthouse and Round Island. The
Breakwater was simply encircled with
DGPS tracking on and then the track
frozen upon completion. The Breakwater
measures about 1250' in total length. The
Lighthouse is located about 500' @ 81°
from the northwest end and about 850' @
353° from the southeast end. Differential
GPS Latitude and Longitude coordinates
are shown.
Several depth soundings were taken
around the Breakwater as shown on
the DGPS image to the left. The
readings shown reflect depths at
mean low tide. A marked 1X2 board
was used to verify electronic
soundings. Most of the soundings
close to the breakwater read 4'-5' all
the way around. The outside of the
dog-leg had a little deeper reading at 6.5' and there were some shallow rocks on the south side of the southeast end. This is actually what gives the appearance of the breakwater being wider at that end since the boat had to avoid this obstruction. It is important to note that the depth quickly shallows to 2' going immediately east of the breakwater and continues for at least 200 yards. This may hamper any additional construction of the breakwater going east.
The Differential GPS unit used is a Northstar 951XD. Satellite information at the time of data collection was as follows: Beginning @ 12:36 PM on 12-20-97, Tracking 9 satellites, Hoop=1.2, Accuracy=10', Differential Beacon was Mobile Point, 300KHz, 100Baud, 30nm. Ending @ 2:12 PM on 12-20-97, Hoop=1.0, Accuracy=8'.
12-20-97 Pascagoula River Tide Information: High @ 1:27 AM = 0.9', Low @ 11:16 AM = 0.1'
Measurements taken between 12:36 PM and 2:12 PM. Little or no tide movement at the time the measurements were taken. There were no noticeable water currents.
Winds were from the East and Southeast at 7-10 knots.
Sunrise @ 6:46 AM Sunset @ 4:57 PM