The English unit HP (horsepower) corresponds to 745,699 W. It is defined as the power needed to lift 550 pounds at a speed of 1 foot/second.
Another HP unit exists in continental Europe and is based on the energy needed to lift a weight of 75 kilos per m/second. This is the version that hydrotherapy devices refer to in their technical documentation. It is equal to 1 CV : or 735,499 W. 1 BHP is equal to 1 English HP, its use to define motor power in European standards is deliberately misleading.
Product information for hydrotherapy devices uses the HP unit. © mezzarenov