Nautical Archaeology - Techniques For Underwater Surveyance, Retrieval, And Analysis, The Development Of Nautical Archaeology, Whole-ship Retrieval

Nautical archaeology is the branch of archaeology concerned with the excavation, identification, and study of the remains of sunken ships. The techniques used in nautical archaeology can be applied to the study of submerged ports, lost cities, sacrificial wells, and other underwater sites.

The ocean conceals a vast number of unexplored, and potentially valuable, archaeological sites. But the technology needed to explore these sites was not perfected until the mid-twentieth century. With the development of scuba gear, underwater transport, and other underwater devices, archaeologists have improved their ability to survey and retrieve objects underwater.

The artifacts, or archaeological finds, removed from the ocean have enriched our understanding of the history of boat building and navigation, as well as broadened our knowledge of everyday life on land. Because of the lower oxygen content of cold water, objects preserved in the ocean deteriorate much less rapidly than they do on land. A 1,000-year-old shipwreck still might contain the wooden implements and food used to cook the sailors' last meal, as well as the clothes they wore to dinner. The chances of finding such objects preserved on land would be extremely slim.

However, not all objects that sink into the ocean are preserved. If an object sinks near shore, it stands a chance of being shattered against the rocks or of being picked up by a curious diver. Even an object that sinks to depths of up to 50 ft (15 m) can be destroyed by the movement of large waves. In addition, organisms inhabiting the lower regions of the sea such as teredos (ship worms) can bore through the object. In a process known as encrustation, barnacles and coral can grow in a thick layer over the object, also causing it to deteriorate.