In both Oxford and Cambridge, there are also separate Town Bumps races in which local clubs compete. Oxford's races, run by the City of Oxford Rowing Club (CORC), are open to all comers and are raced in fours, all races taking place on the same day. Cambridge's races are run under the auspices of the Cambridgeshire Rowing Association (CRA) and are run exclusively in eights and take place over 4 consecutive days in July. There are typically four men's divisions with 17 boats (plus a sandwich boat; a sandwich boat being the top boat from each division) in each division, and three women's divisions. The bumps are fiercely contested, and the ideal that the races are for local rowers can lead to disputes over whether crews are 'legal'.