 But that was precarious. He knew how long it took him to earn that much money, to save up that much money. And so he knew that there was a United States blockade, a federal blockade just outside the mouth of the harbor. And he knew that if he could somehow figure out a way to get there, that he'd be free. And so he noticed that the Confederate crew from time to time would leave for the night. They weren't supposed to, but they would leave for the night not to come back until the next day.