Does Swimming and Diving Break the Fast?
Question

What is the ruling on swimming and diving for one who is fasting?
Praise be to Allah.Sheikh Ibn `Uthaymin (may Allah have mercy on him) said:
“There is nothing wrong with a fasting person diving into water or swimming in it, because that is not among the things that break the fast. 
The basic principle is that things are permissible unless there is evidence to show that they are makruh or haram. There is no evidence that swimming is makruh or haram, rather some of the scholars regarded it as makruh lest anything enter the swimmer’s throat without him realizing it.” (Fatawa Ibn ‘Uthaymin, 19/285) 
He also said: 
“There is nothing wrong with a fasting person swimming, and he may swim as he wishes, and dive into the water , but he must take care to avoid letting water get into his stomach as much as he can.” (Fatawa Ibn ‘Uthaymin, 19/284 )
It says in Fatawa al-Lajnah al-Daimah, 10/282 
“Swimming is permissible during the day in Ramadan, but the swimmer must take care to avoid letting water reach his stomach .”
And Allah knows best.