Abstract: A submersible device for cleaning and scrubbing the bottom and/or sides of a pool or the like comprising a housing having a width in the left-right direction greater than its length. An elongate brush of a dimension approaching the width of the housing is mounted in the lower part of the housing, with the bristles of the brush protruding somewhat below the housing. An electric motor carried on the housing is utilized for driving the brush in rotation, and wheels on the underside of the housing enable it to roll along the bottom of the pool. The housing is made of flexible components such that a substantial portion of the width of the brush can remain in contact with the bottom of the pool as a result of flexing. I prefer to use a rotary brush whose bristles are in a double helix configuration such that encountered particles will be drawn toward the midpart of the housing. Suction will be applied at a location on the centerline of the housing.