Abstract: A dewatering module adapted to be inserted between a rock drill bit and a drill string comprising an outer housing and having a first end remote from the drill bit and a second end adapted to lie immediately adjacent the drill bit; an air/water inlet at the first end of the module adapted to receive a high pressure composite air and water flow from within the drill string and to deliver said flow into a main chamber within the module; an inner tubular housing within the chamber defining a passage within the chamber from its first and inlet end adjacent the air/water inlet to its outlet and second end at the drill bit; the first and inlet end of the inner housing being shielded by a first baffle from the composite air water flow entering the chamber; the first baffle comprising a deflector overlying the first and inlet end of the inner housing and having a skirt being of larger diameter than the tubular inner housing inlet such that air entering the inner housing is forced to reverse direction and traverse an