Competitive swimming began in the late nineteenth century. It is a popular leisure activity that is a major competition sport in many countries. Since the inception of competitive swimming, some form of mathematics has been used during the competition in many ways. Mathematics is essential and involved with the sport of swimming in many ways, such as pool dimensions, training and stroke technique. Pool measurements are an essential part of how mathematics is involved with the sport of swimming. There are three distinct distances that pools can be; they are called short course yards, short course meters and long course meters. For all competitions, the pool must be 50 m. (164 ft. 1/2 in.) long for long course events, or either 25 m. (82ft. 1/2 in.) or 25 yd. for short course events (Copyright Diagram Group). A pool width of between four and 10 lanes is normal (Copyright Diagram Group). Each pool is bounded by lane ropes. Lane ropes, made up of colored floats 5-15 cm. (2-6 in.) in diameter, must be a distinctive color for a distance of 5 m. (16ft. 5 in.) from each end of the pool for long and short course (meters) events, or 15ft. for short course (yards) events (Copyright Diagram Group). An overall depth of 2 m. (6ft, 7in.) throughout the course length is recommended (Copyright Diagram Group). In addition, there are measurement markers on the bottom of the pool that are a "T" shape. The purpose of these marks is to mark the center of each lane and it is used by swimmers