 The crew thought it was important for the audience to see the waves and the ocean.However, they were unable to finish filming the scene within the course of one day, so the crew made a quick decision to place a makeshift blue screen as part of the background for the interior of the boat.It was intended that the blue screen be edited in post-production in order to represent the ocean, but upon learning that this change would cost millions of dollars, the crew decided to forgo the alteration and instead pass off the blue screen as a tarpaulin.