What women should wear in pool depends on the surrounding area and your own choice. It is widely seen that women are wearing Burqinis and shorts in the pool. In Riyadh, I have seen women even jumping into pools wearing full black Abayas or Burqinis as well. It depends on your preference. I have also seen one of my friends wearing full sleeved top with baggy pants and the other one wearing half Burqini with short sleeves.
Women Only Private Pool Parties: When there is a just pool party for women only, where I once went with my friends, it is seen ladies wearing whatever they feel like. Few of them were wearing the usual two-piece bikinis because they had superb slim and smart bodies to show off and those were in fact mommies. How lucky! They didn’t mind showing their butt and cleavage while few of them wore shorts and tight t-shirts because they were comfortable that way. All these women laid by the pool, sunbathing their bodies and working on the tans. Men were not allowed here so they were guided elsewhere.
Farm House Pool Parties with Mixed Gathering: Also, once I was invited to a family farmhouse party where I was told to get my swimwear along as there was a pool there. I grabbed my two pieces of course. There were women over there from ages 17 till 70 years and all of them wearing whatever they were comfortable in ranging from t-shirts to full sleeved tops to even bikinis. Men stayed inside the house when they knew women were swimming. Similarly, when it was time for men to swim, the women stayed indoors.
Swimming in Public: When swimming in public, ladies use Burqini whether within Saudi Arabia or outside, which are available in amazing colors and even double shaded ones are in the market now. When we were searching for a new house for rent, it had a small pool. When inquired, we were told that yes ladies can swim in it if they wear abaya because in case if any man comes, the woman is found wearing the abaya. I have seen that every woman loves swimming and dipping in the pool be it young or married with kids. It is not necessary that everyone has a pool in their backyard for swimming. Some of them fulfill this wish of theirs by paying SR 50 to Al Manahil.
Swimming in Hotel Pools: There are outdoor pools in hotels as well but women cannot dip in because of the fear of being gazed by men through the transparent windows as it is all open. Few of them even have indoor pools. In that case, women can easily swim over there, in the women-only hours, guarded by security at the doors to prevent men from entering. So, we discussed all the aspects and places where women swim and the answer to the question, if it was compulsory to wear Burqini for swimming of women, is No! It is not compulsory but it just depends on your choice and preference. Happy Swimming!