Underwater Archaeology is that branch of the discipline and science of Archaeology that is practised under water, either by archaeologists equipped with breathing apparatus or by the remote control of machines.
Underwater archaeology is most often considered as a branch of maritime archaeology (the archaeology of aquatic vessels and associated infrastructure), though not exclusively: underwater excavation techniques and methodology can also be applied in the study of submerged settlement and burial sites, for instance.
A prime example of the latter is the ongoing investigation of the remains of Ptolemaic Alexandria in Egypt by Franck Goddio, amongst others.
Underwater archaeology is the study of past human life, behaviours and cultures using the physical remains found in salt or fresh water or buried beneath water-logged sediment.
Shipwrecks (such as The Mary Rose) can also be important for archaeology because they can form a kind of accidental time capsule, preserving an assemblage of human artefacts at a moment in time i.e.
A working platform for underwater archaeology needs to be equipped to provide for specialist remote sensing equipment, analysis of archaeological results, support for activities being undertaken in the water, storage of supplies, facilities for conservation for any items recovered from the water, as well as accommodation for workers.