The native Maldives and Islamic traditions are famously much more discreet in their female fashions. Such sartorial covering is fine but the extra garments can be a hindrance swimming in the water. Hence the “burkini”. A swimming costume designed to provide the modesty of a “burqa” with the fabric and styling optimised for swimming (like a “bikini”). Actually, the “burqa” is the traditional Islamic dress that even covers the face. In covering its closer to the “khimar” (so maybe a better term is “bikhimi”?).
Such garments are traditional for Muslims, but also a great solution of the sensitive of skin. My father has had a number of skin cancers and only goes out well covered up on sunny days making swimming not easy nor enjoyable.