This is done entirely in small boats known as keelboats and dinghies. A keelboat has a weighted keel to keep it upright and a dinghy just uses a centreboard and the boat must be balanced by the crew. These were divided into different groups of identical boats called Classes. The first sailing Olympics took place in 1900 at Meulan near Le Havre in France. Over the years the classes of boats allowed to compete have changed because of new design and technology.