NOWRAMP 2002

On Finding Wrecks
Written By Hans Van Tilburg, Ph.D, "Dr. Shipwreck"

The 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 small dots.

Those 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.

The 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 of expedition.