A formal method of communicating between two ships at sea. When two ships met at sea, they would come aside of each other. The captain on each ship would stand on deck with a speaking trumpet, a horn-like device that would amplify his voice across the water. They would pass onto each other information such as the name of their ship, where they were bound, how many days out, and how many barrels of oil they had. Each ship would display a large blackboard with the latitude and longitude on it to compare figures for accuracy. If the ships were not in pursuit of whales, the interchange often concluded with a "gam," when the crews could spend time visiting with each other.