Most of the techniques used by maritime archaeologists today for the location of sites originate from other fields, particularly the offshore oil industry, although the equipment and resources that are generally used by maritime archaeologists are modest in comparison. Even though high-technology equipment has been used to find sites over the years, the majority of archaeological wreck sites have in fact been found by chance, often through the fishing industry.
The three main systems used to locate sites are visual searching, either using divers or remotely operated vehicles with video cameras; magnetometers that detect the presence of ferrous metal (usually applied to searching for iron shipwrecks); and sonar, particularly side-scan and multibeam sonar, that presents a sonar image of the sea bed. The use of remote sensing equipment is becoming common now that it is more readily available and, unlike diver operations, can be conducted over long periods of time without interruption.
Where a maritime archaeologist is faced with the need to locate a site, it is essential to carry out the appropriate initial research prior to the survey, and that the survey is conducted in a systematic manner. Often, in the past, searches have been conducted with totally unscientific and illogical principles. However, today with the advent of precise positioning through the Global Positioning System (GPS), with a cheap hand-held instrument, a position can be determined anywhere on the surface of the Earth to an accuracy off by just a meter or so.
World History
