The precise recording of swimmer's times in competition was a difficult task in the pre-electronic era. As swimmers raced to the finish in an event where there might be four or five competitors within inches (centimeters) of one another, the splash created by each racer as they drove for the end of the pool made the visual determination of whose hand touched first to be a very difficult and occasionally inaccurate exercise.
In 1967, the Omega company of Switzerland developed the first electronic timing system for swimming that attempted to coordinate the physical the recorded time. This new system placed contact pads (known as touch pads) in each lane of the pool, calibrated in such a fashion that the incidental water movement of the competitors or wave action did not trigger the pad sensors; the pad was only activated by the touch of the swimmer at the end of the race.
The touch pad technology was refined after 1967. The pads themselves are now constructed from a series of very thin vertical sheets, which extend underwater the width of a competitor's lane, so as to permit a recorded touch no matter where in the lane the swimmer may finish the race.
The starting block is also integrated into the over all timing system. The starting block is equipped with a speaker system to permit the starters horn to be directly communicated to each competitor as they await the start. When the swimmer leaves the starting block, the motion of the athlete signals the individual start by its registration on a sensor device in the block. The timer and the judge of the race can instantly determine, through the coordination of the starter's signal and the athlete movements as recorded on the block, whether there was a false start, and in which lane.
In the same fashion, the timing system is coordinated with the video recording of each race, to permit judges by replay to determine the order of result in the event of any dispute.
Swimming results in international competition are now resolved to an accuracy of one thousandth of a second. In the 1988 summer Olympics at Seoul, six competitors in the men's 100-m breaststroke finished within 0.5 seconds of one another. Since 2000, the results of most major international swim meets have been available in real time by the Internet.