An excavation apparatus (5), such as an underwater excavation apparatus and/or a controlled flow excavation apparatus, comprises a rotor (10) comprising a plurality of first rotor blades (12) and a plurality of second rotor blades (14). The second rotor blades are provided between adjacent pairs of first rotor blades. The first rotor blades (12) define a plurality of primary rotor blades of the rotor (10). The second rotor blades (14) define a plurality of secondary, splitter, rotor blades of the rotor (10).

Hydro excavation vacuum apparatus that process spoil material onboard the apparatus by separating water from the cut earthen material are disclosed.

Hydro excavation vacuum apparatus that process spoil material onboard the apparatus by separating water from the cut earthen material are disclosed.