Sports bras are great to wear for swimming especially when you are jumping off of a diving board or a rope swing, etc. I don't know if other girls have this problem but for me swimsuit tops will come up when I jump into the water - even when I tie them as tightly as I can. It makes it hard to have fun jumping off of stuff into the water when you are constantly worrying if you can quickly fix your top if need be before you surface. Anyways, I have found that sports bras don't have that issue!