Inshore powerboat racing is a form of water-based motorsport using powerboats in sheltered or inland stretches of water, including lakes, rivers, docks and sheltered bays. It is often referred to as circuit powerboat racing because of the frequency of inshore races to use the format of a circuit loop, around which boats race for a number of pre-determined laps. International races and championships are administered by the Union Internationale Motonautique (UIM) while national events are organised by the relevant country's own powerboat association.