A pedalo or paddle boat is a small human-powered watercraft that a person drives by pedaling, which turns a paddle wheel. The paddle wheel of a pedalo is a smaller version of that of the paddle steamer. A two-seat pedalo has two sets of pedals, side by side, designed to be used together. Some models have three pedals on each side to allow a person to pedal from the center when boating alone. Pedalos are suited to calm waters, such as in ponds and small lakes. They are sometimes rented for use on ponds in urban parks. Perhaps the earliest record of a pedalo is Leonardo da Vinci's diagram of a paddle-powered craft driven by two pedals.