Written By Hans Van Tilburg, Ph.D, "Dr. Shipwreck"
ocean is the largest haystack in the world, and in it, ships
are the tiniest of needles. No matter whether a ship is
30 feet long or 600 feet long, when placed in comparison
to the true size of the ocean, they are simply infinitely
who search for shipwrecks, then, need to employ high technology,
such as side scan sonar and magnetometers. Both of these
are basic tools for remote sensing surveys, for finding
things from a distance without the use of the human eye.
Side scan sonar uses sound pulses and reflections from the
ocean bottom to paint an acoustic "picture" of
the sea floor. Magnetometers detect concentrations of iron.
Both tools have sensors which are towed slowly behind the
survey vessel. Such surveys are painstakingly slow, requiring
many hours and days as the equipment is towed back and forth,
systematically covering every square foot of seafloor. This
is usually how previously non-located wrecks are discovered.
Diving is actually a very small part of the search process.
maritime archaeology team on the NOWRAMP 2002 expedition
is working in coordination with many other scientists and
scientific tasks. The vessel Rapture spends only
a day or two in most locations. Therefore the maritime team
is focusing its efforts on previously located wrecks and
submerged material sites. Sometimes wrecks are at their
reported positions, sometimes they're not. To truly survey
for non-located wrecks would require a very different type