Three types of race courses are typically used with 50-meter pools: 25-yard, 25-meter and 50-meter.
25-yard courses are often used for high school and college competitive swimming. These can be set up in several different ways. For instance, you can either start or end from the bulkhead, and swim toward or away from the deep end. The recommended pool depth is six feet for NCAA or two meters for FINA when starting off a starting block. Additionally, you can have the pool set up for 25-yard cross course swimming. If you have a 50-meter pool without a bulkhead, this is the only way to get a 25-yard course. If there is a cross course setup with bulkheads, it's possible to set up the pool to have several cross course lanes for practice or multiple meets, rather than the typical eight or 10 lanes.
50-meter course setup options depend on the number of bulkheads the pool has. Without a bulkhead, swimmers start from the deep end and swim the length of the pool to the shallow end. In the case of an all-deep pool, the starting point does not matter. If the pool has two bulkheads, swimmers swim from one bulkhead to the other. Additionally, aligning the bulkheads next to each other creates a large walkway where swimmers can finish at the shallow end. 
50-meter courses are typically used for long-course swim practices or for those swimmers training for the Olympics. While there are some 50-meter meets at the college level, 25-yard meets are more popular in the United States.
25-meter courses are not seen very frequently in the United States and are generally only used when hosting an international meet. 25-meter courses need at least one bulkhead placed in the middle of the pool. Swimmers either start from the deep end and swim to the bulkhead, or start from the bulkhead and swim to the shallow end. With two bulkheads, both are placed in the middle of the pool, where swimmers can either start from the bulkheads to the shallow end, or start from the deep end and swim to the bulkheads. In an all-deep pool, swimmers swim to the bulkhead from either end. Olympic courses are 50 meters long and 25 meters wide without a bulkhead. In this setup, 50 meters would be the main race course and the cross course would be the 25-meter course.
When designing a pool, it's important to consider some of the different ways it can be configured to best accomplish its purpose. Working with an aquatic facility consultant ensures your pool will have the functionality to meet all of the goals you set out to achieve, as well as meet all industry regulations. Check out Counsilman-Hunsaker's Portfolio of Services for more information!