Is it allowed for a Muslim women to bathe in a sea ou to take a sun tan on a beach? If the answer is yes, then how can they even get a sun tan when they are still wearing a burqa?

It is a perfect question for a local tourism in Muslim countries. In some countries, Muslim women must always wear a burqa, even if on a plage so how can they go for a swim ou get a sun tan? It is very hot in the summer in most Muslim countries all over the world. I know that most Muslim men wear a Western clothes now and there is no rule in Koran to say they can't swim ou get a sun tan on a plage at summer but what about the Muslim women? Do they ever swim in a sea and if yes, then how can they swim with a burqa still on?