Abstract: An underwater cleaning apparatus having a carrier, a plurality of wheels for shifting the position of the carrier along a submerged surface, a plurality of rotary brushes carried by the carrier and adapted to clean the submerged surface, and a source of power for rotating the rotary brushes. The apparatus further comprises flexible partition wall members for transmitting torque to the rotary brushes and forming reduced pressure chambers communicated with spaces formed by bristles of respective rotary brushes. As the rotary brushes rotate, the rotary brushes and the partition wall members in combination serve to provide vacuum to produce a force to press the carrier through the wheels onto the submerged surface to be cleaned. In addition, each of the rotary brushes are allowed to individually follow the configuration of the surface thanks to the flexibility of the partition wall members.