Reearchers investigating the archaeology of shipwrecks need to understand the processes by which a wreck site is formed so that they can allow for 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 sea-worthiness, 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 segregated officers and seamen.

Archaeological theories of shipwrecks

Muckelroy's model

A systematic model for the characterisation and interpretation of the archaeology of shipwrecks was first proposed by Keith Muckelroy in 1976 Muckleroy, K., 1976. The integration of historical and archaeological data concerning an historic wreck site: The 'Kennemerland'. World Archaeology 7.3 pp 280-289. Muckelroy's system model describes the evolution of the material remains of the ship from the wrecking process, subsequent salvage operations and the disintegration and rearrangements of the remains from environmental factors. Although Muckelroy considered both natural processes and human activity in his model, subsequent research has mainly expanded the environmental factors and there has been little published on the human processes.

Considering human intervention

A paper by Martin Gibb in 2006, Gibb, M., Cultural Site Formation Processes in Maritime Archaeology: Disaster Response, Salvage and Muckelroy 30 years on. International Journal of Nautical Archaeology vol 35.1 pp 4-19 expands Muckelroy's model to consider human behaviour at the time of the disaster and the long term relationship between people and shipwrecks. This model utilises studies of humans involved in disasters to characterise the human activity into phases around the time of the wrecking. This model considers:

• Pre-impact threat phase, in which humans considering the risk may take avoiding action which results in there being no wreck, or may take unsuccessful action to mitigate the perceived threat, for example the wreck location may be the result of attempting to avoid some perceived greater threat. Stowage of cargo may also indicate consideration of threat.
• Pre-impact warning phase, in which humans may take drastic action to avoid catastrophe, for example, running a vessel ashore, jettisoning cargo or running out anchors.
• Impact, in which the decision is made to abandon ship or remain aboard, and, for example, attempt to refloat.
• Post impact, where survivors regroup and, for example, salvage their own goods or make repairs.
• Rescue and Post-disaster where the vessel is abandoned and in which third parties may be involved in salvage or in removing remains that present a hazard to navigation.

See also

• Maritime archaeology
• Underwater archaeology
• Rusticle
• Wreck diving
• Nautical Archaeology Society

Famous shipwrecks

• Uluburun Late Bronze Age shipwreck, 14th century BC
• Cape Gelidonya Late Bronze Age shipwreck, c. 1200 BC
• Antikythera c 80-50 BC, includes the astronomical computer, the Antikythera mechanism
• Mary Rose, 1545
• Vasa, 1628
• VOC ship Batavia, 1629
• VOC ship Amsterdam, 1749
• HMS Pandora ^*1791
• Medusa 1816
• RMS Titanic, 1912
• Bismarck, 1941
• USS Arizona, 1941

Famous wrecksites

• Ancient & refugee ships of the Baltic Sea
• German High Seas fleet of Gutter Sound in Scapa Flow
• Truk Lagoon
• Pearl Harbor
• Takashima island off the Japanese coast of Kyushu in the East China Sea

Footnotes