You would think that pushing an overcrowded boat of terrified refugees for over three hours in Greek waters might put Yusra Mardini off swimming. But for the two-time Olympic competitor, getting back in the water was actually key to acclimatising when she reached Berlin as a refugee. “Swimming helped me get comfortable in a country where I didn’t know anyone and didn’t speak the language. It was the only familiar thing I knew and made me feel safe,” Yusra tellsThe New Arab as we speak shortly after the paperback release of her memoir, Butterfly: From Refugee to Olympian, My Story of Rescue, Ho…