The leader of an 11-day sea voyage to assert Chinese sovereignty over the Diaoyus in August was prosecuted yesterday for leaving city waters without permission. The Marine Department said in a summons that Lo Chau, who owns the 32-metre vessel Kai Fung No 2, had ignored the department chief when he said the boat could not leave city waters without a valid excuse on the night of August 12. Eight members of the Action Committee for Defending the Diaoyu Islands were on the boat that sailed to the disputed islands in the East China Sea, known as the Senkakus in Japan, where they made the first landing by Hong Kong activists in 16 years. Lo led the mission. He was ordered to appear in Eastern Court on March 14. Leung Chun-ying's administration has no basis to proceed or retreat now. There were no grounds for prosecution. What laws did we break? Committee member Tsang Kin-shing, who was on the boat in August, said the prosecution "humiliated the country and forfeited its sovereignty". "Leung Chun-ying's administration has no basis to proceed or retreat now. There were no grounds for prosecution. What laws did we break?" Tsang asked. He said the boat was a licensed fishing vessel and did not need a permit to sail out of Hong Kong waters. In a well-planned act that surprised the city, eight activists from the committee, two journalists and four crew members managed to evade marine police and an interception attempt by Japanese coastguard vessels as they approached the islands. Eight of the activists pitched the Chinese flag on the island. All 14 people on board were arrested by Japanese authorities. They were deported on August 17 and returned to Hong Kong. Tsang said they had made nine previous unsuccessful attempts to sail the boat to the Diaoyus. Each time the vessel had been intercepted by marine police and towed back. Tsang said: "By treating us this way, the government is actually supporting Japanese Prime Minister Shinzo Abe in their sovereignty claim over the Diaoyus."