a submersible cleaner includes a valve within a flow passage for interrupting fluid flow and thus drive the cleaned over submerged surfaces to be cleaned . a retractable element moveable between the valve and a wall within the passage reduces a gap formed between them such that flow through the passage is directed along one side of the valve resulting in improved driving power and reduced clogging by debris passing through the passage . the retractable element may be attached to either the valve or the wall , and may make slidable engagement with between them . a flexible plate engaging the surface includes a plurality of tongues radially extending about the periphery with each tongue having a lower surface portion contacting the surface to be cleaned and an outmost portion contoured away from the surface .