 Since the late 1970s, Charco Azul has unloaded oil from Alaska to be shipped to the refineries of Houston and the Gulf coast of the United States.Originally it was a stopping spot for supertankers to unload and Panamax tankers to load to carry the oil across the Panama Canal.In 1982, the Trans-Panama pipeline was commissioned to transport the oil across to isthmus, with Charco Azul at the southern end.