 While preservation in situ is not assured, material that has survived underwater and is then recovered to land is typically in an unstable state and can only be preserved using highly specialised conservation processes.While the wooden structure of "Mary Rose" and the individual artifacts have been undergoing conservation since their recovery, provides an example of a relatively recent (metal) wreck for which extensive conservation has been necessary to preserve the hull.While the hull remains intact, its machinery remains inoperable.