In this Part:
"Commonwealth explosives area" means any Commonwealth land declared by the regulations to be an explosives area and, where any such land consists of a part of the bed of the sea, or of a bay, estuary or river, includes the waters above the land.
"Commonwealth land" means land the property of the Commonwealth and includes any other land:
(a) in which the Commonwealth has a legal or equitable estate or interest; or
(b) over or in connexion with which the Commonwealth has a right, power or privilege.