The actor plays titular castaway Pi Patel in the upcoming fantasy movie, which is almost entirely set on a boat at sea, and director Ang Lee admits shooting was slow going at first - because the newcomer couldn't keep himself afloat in the 18-foot (five metre) production tank.
He tells New York Magazine, "The wave tank could create long surges like the open ocean, so his raft could act and interact with water before it was digitally extended to the horizon. But he wasn't going to drown... After I cast Suraj Sharma... I tested him to see how long he could hold his breath, and it was only for fifteen seconds - and we had shots planned that would require him to do that for a minute long! So he had to learn."
But Lee insists he refused to recast the role, adding, "Everything else, you look at him and you see he is Pi."