The form is mainly used in intercollegiate competitions at the University of Oxford since 1815, and at the University of Cambridge since 1827. Bumps racing in fours is also the format of inter-house rowing at Eton College and Shrewsbury School. It is particularly suitable where the stretch of water available is long but narrow, precluding side-by-side racing. Bumps racing gives a sharper feel of immediate competition than a head race, where boats are simply timed over a fixed course. Few rowers worldwide use rivers as narrow as the Cam or the Isis, but bumps races are also contested elsewhere.