Cox boxes are mainly used in eights and fours rowing, where the readouts are used by the coxswain to monitor the performance of the crew and manage the race. This is of particular importance in time trial races where crews race astern (as opposed to side-by-side) and so the performance of other crews cannot be easily gauged.
Cox boxes are primarily used in eights and fours rowing, with the coxswain using the readouts to monitor the crew's performance and manage the race, particularly important in time trials where crews race astern (as opposed to side-by-side).