underwater cultural heritage "underwater cultural heritage" means all traces of human existencehaving a cultural, historical or archaeological character which have beenpartially or totally under water, periodically or continuously, for at leastone hundred years such as— (a) sites, structures, buildings, artefacts and human remains,together with their archaeological and natural context; (b) vessels, aircraft, other vehicles or any part thereof, their cargoor other contents, together with their archaeological andnatural context; and (c) objects of prehistoric character; ACT 645 - NATIONAL HERITAGE ACT 2005 2. Interpretation.