 FAKE: After Will And Jack commandeer the Interceptor, the ship is  viewed from above, sailing on a beam reach (a point of sail in which  the boat is at 90 degrees to the wind). When Jack knocks Will off  the ship with the boom, he jibes the boat, causing the sail to shift  positions suddenly. In order to do this from the previous position,  he would have had to turn the ship almost completely around. This  would have taken well over a minute. Jack did this in less that  three seconds. The sail is also filled to the wrong side while it  sweeps Will off the deck.