Archaeology studies human cultures through the analysis of their historical traces and their context. It aims at explaining the origin and development of civilizations, as well as the understanding of culture and history. Underwater archaeology is a sub-discipline, which studies submerged sites, artifacts, human remains and landscapes. It is to be seen in the larger context of maritime archaeology, which studies human relations with oceans, lakes and rivers and is complemented by nautical archaeology, which studies vessel construction and use.

Archaeological sites located under water are an important source of historic information. They contain traces of human existence transformed under the impact of environmental factors that differ from those present at sites on land. Often however, due to the lack of oxygen, these sites still contain material that is lost on comparable sites on dry land.

Techniques

The surveying, excavation and preservation of sites are important phases of the process of underwater archaeological research. A variety of archaeological sciences are used in underwater archaeology.

It draws upon 

-The study of history and writings relating historic events;

-Physics, information sciences, and chemistry,  

-Cultural anthropology, which studies the different cultures and their    variation, examining the impact of interchange,

-Dendrochronology, which serves to date timbers,

-Archaeobotany and archaeozoology  to understand plant and animal material (for instance the identification of pollen samples, seeds or animal skeletons),

-X-rays of concretions to identify their interior or to make writings visible,

Geology , which can inform about soil movements transforming a site or changes in sea level, erosion or deposition of sediment material.

Qualifications

Archaeological sites are very fragile and sensitive to intrusion. Even an intervention that opens a site for research purposes “damages” the archaeological information contained therein, as the site is no longer undisturbed. It is therefore important that information contained within the site is carefully recorded.

The 2001 Convention therefore regulates in its Annex, containing the “Rules concerning activities directed at underwater cultural heritage”, that only qualified and properly trained persons should be permitted to intervene on submerged sites.