There is provided an item which floats in a body of water. The item includes a body having a surface provided to form at least part of the underside of the item and an opposing surface. The item includes apparatus comprising at least one channel which passes between the surfaces and allows the passage of water therethrough. A means provided to influence and/or be influenced by the passage of the water through the at least one channel to exert a propelling and/or controlling force on the item.