The United States President Barack Obama will travel to America's Gulf coast tomorrow for a first hand look at one of the United States' biggest oil spills in decades. His plans to survey the disaster zone come as weather hampers efforts to contain the spill and stop it from threatening the coastline. Satellite images show the oil slick has more than tripled in size in just a day. It is now lingering off Louisiana, dangerously close to some of America's most important ecosystems.<br/>