Abstract: A portable ultrasonic descaling device provides an improved method to remove calcium deposits and stains from the surfaces of swimming pools and other structures in contact with water. The handheld device comprises a water-resistant housing, within which are mounted an ultrasonic transducer, a fluid pumping system, a cleaning blade, a controller, and a power source. The ultrasonic transducer drives both the pumping system and the cleaning blade. The fluid pumping system draws fluids from a water source and through the device, cooling the transducer, cleaning blade, and surfaces being descaled by fore mounted spray nozzles. The power source comprises batteries to power the device. Lighting may also be fore-mounted for illumination and is connected to the circuitry along with a visual indicator. Direct contact of the calcified buildup with the oscillating cleaning blade and water spray from the nozzle heads causes breakdown of the deposits by cavitation.