Reference: Fataawa Ramadhaan v2 p525 no.491
Fiqh al-‘Ibaadaat libni-‘Uthaymeen p191
Question: What is the ruling concerning swimming or floating in water whilst fasting?
Response: There is no harm in diving into water, floating or swimming because this is not from that which breaks the fast. The basis [for everything] is permissibility until [authentic] evidences proves a prohibition or a disliking [for that]. For this, there is no evidence indicating a prohibition or dislikeness. However, some people of knowledge dislike this out of fear that some water may reach the throat without [the person] feeling it.
