Archaeology of shipwrecks

The archaeology of shipwrecks is the field of Archaeology specialized most commonly in the study and exploration of shipwrecks. Its techniques combine those of archaeology with those of diving to become Underwater archaeology. However, shipwrecks are discovered on what have become terrestrial sites.

It is necessary to understand the processes by which a wreck site is formed to take into account the distortions in the archaeological material caused by the filtering and scrambling of material remains that occurs during and after the wrecking process.

"When a ship is wrecked, it suffers many changes of state until the remains eventually reach equilibrium with their environment. Initially, the wrecking process changes it from the human organised form of a working vessel to an unstable state of structure and artefacts underwater. Natural forces act upon it during the wrecking process and continue to act until equilibrium is reached. Heavy items sink rapidly, lighter items may drift before sinking, while buoyant items may float away completely. This causes a filtering and scrambling of the material remains. The sudden arrival of a structure on the seabed will change the currents, often resulting in new scour and deposition patterns in the seabed." Once underwater, chemical processes and the action of biological organisms will contribute to the disintegration. At any point in these processes, humans may have intervened, for example by salvaging items of value.

Prior to being wrecked, the ship would have operated as an organised machine, and its crew, equipment, passengers and cargo need to be considered as a system. The material remains should provide clues to the functions of seaworthiness, navigation and propulsion as well as to ship-board life.

"Finally the ship as a means of transport can be considered as an element in a geographically dispersed social, political and economic system. Warships impose political will by force; cargo vessels exist in a system of commerce; while passenger carrying vessels give clues to social classes and structure. Social status may also exist within the ship, for example, between officers and seamen."

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