We transport asphalt, fuel oil, gasoline, sulfur and other bulk liquids. We own a fleet of inland and offshore tows that provide marine transportation of petroleum products and by-products produced in oil refining and natural gas processing. Our marine transportation system operates on the United States inland waterway system, primarily between domestic ports along the Gulf of Mexico Intracoastal Waterway, the Mississippi River system and the Tennessee-Tombigbee Waterway system. Our inland tows generally consist of one pushboat and one to three tank barges, depending upon the horsepower of the pushboat, the river or canal capacity and conditions, and customer requirements. Our offshore tows consist of one tugboat, with much greater horsepower than an inland pushboat, and one large tank barge. Our largest marine transportation customers include major and independent oil and gas refining companies, petroleum marketing companies and Martin Resource Management. We conduct our marine transportation services under spot contracts and under term contracts that typically range from one to 12 months in length