Do the following to have more goods to arrive with a ship than there were when loading the ship. Note: The ability to go to the Bayou at will is required. First, load a ship completely with a good and send the ship off to another port. Exit the trading screen, then leave the city and travel to the Bayou. Now return to the City once arriving in the Bayou and then return to the trading screen. All ships that were sent are in port regardless of how much time has passed. Finally, select a ship to trade and select Sell Goods. Three sets of the same goods should be available for sale, and each set has the ship's maximum load-- which means the ship is currently carrying 3x its maximum load and 200% more than what it left port with. You can do this with any number of ships.