Is fasting invalidated by swimming? Can swimming invalidate the fast? Is the fast broken by swimming? Will swimming affect the validity of the fast?
Swimming does not invalidate fasting if no water is taken into the body and reaches stomach through mouth or nose. However, the swimming person may swallow water because of waves or other reasons. In this regard, it is more cautious not to swim while fasting.
Source: Presidency Of Religious Affairs The Turkey, High Board of Religious Affairs FATWAS