A combination aquatic toy and a reservoir wherein the reservoir comprises a container to contain a body of water and a contactless electrical power transfer transmitter, the toy is a submersible or is submersible and comprises a body carrying a battery and a battery powered propeller (fin or screw propeller or foil or impeller or other) to drive the toy through the body of water and contactless power transfer receiver to receive power, when in sufficient proximity to the transmitter, from the transmitter.