Yes, it is true that they cannot wear the appropriate skin revealing swimming costumes or a regular swimwear as per the dressing norms of their religion. But this does not mean that they cannot enjoy swimming in the scorching summer heat. They need to get the Islamic swimming suit or swimwear which is modest and decent, and as per the Islamic religion. Nowadays, the various special retail Islamic stores and the online Islamic stores have in their shelves different kinds of Islamic modest swimwear and clothes relevant to girls and boys who want to swim.
Usually, the most common design of a swimwear for a Muslim woman is like a complete body suit, made of water proof material and covering the entire body from neck to toe. This swimming costume also comes with a swimming cap, like a skull cap or Hijab that keeps the hair covered.....
Read More at- https://medium.com/@Eastessence/islamic-swimming-suits-depicting-modesty-decency-comfort-and-fashion-6f01330ab62b