The aquanator is a proprietary device using aquafoils (an underwater version of airfoils) to generate electricity from water currents. These devices can be likened to underwater windmills. Unlike traditional tidal power, no weir is used to obstruct the flow of water. Such weirs can potentially disrupt the marine ecology.

Atlantis Energy Limited based in New South Wales:

has developed a machine called an aquanator which converts ... ocean and river currents into ... electricity ... uses aquafoils, in effect underwater sails propelled by ocean or river currents. ... would form underwater 'farms' of Aquanators feeding ... electricity into existing coastal power grids or individual units servicing remote and island locations.^*

Inventor Mick Perry, said the machine, still in it's prototype stage of 2003, works by harnessing the energy of currents and tides in under water parachutes, and using it to pump water to shore which then turns a motor that generates electricity.^*

Stronger currents generate significantly more power:

2.5 knots produces around seven kilowatt hours (kWh), five knots creates ... sixty kWh.^*

Currents of about 2.5 knots will rotate aquafoils on the generator, which is 57 metres across and nine metres high, producing one megawatt of electricity - enough to power 660 households daily.^*

Renewable energy | Energy conversion