The climate activist group 'Rising Tide' said the coal ship was forced to turn back after small boats and swimmers entered the shipping channel. A spokesperson for Newcastle Port said one vessel was prevented from entering the port, but otherwise 'shipping has not stopped and will continue as scheduled'. A protest by climate activists off the coast of Australia yesterday forced a coal ship to turn back before reaching the country's largest coal export port, resulting in the arrest of 11 people. New South Wales police said the detainees were charged with 'suspected maritime-related offences' in connection with the protest near Newcastle Port, 170 kilometers from the state capital, Sydney.