The Philippines will ban single-hull oil tankers from its waters from April, two years earlier than planned, after the worst oil spill in the country's history and a separate leak in South Korea. Vessels carrying "black" petroleum products such as crude oil and bunker fuel won't be allowed to dock at ports from April 1 without a double hull, said Transportation Undersecretary Len Bautista in a phone interview from Manila. The single-hull crude oil supertanker Hebei Spirit caused the worst spill in South Korea's history last month after it was struck by a crane causing it to lose 66,000 barrels of crude oil, about 1/3 the size of the Exxon Valdez spill of 1989.