Authorities have responded to avert the spread of an oil spill to other areas as a motor tugboat sank off Naga, Cebu, the Philippine Coast Guard (PCG) bared Monday, Sept. 4.br br The PCG said that MTug Sugbo 2 sustained a hull damage on its steering portion inside the engine room while traversing the vicinity waters off Naga Anchorage on Sunday, Sept. 3.