About 25 activists will set off for the disputed Diaoyu Islands next month to mark the Japanese invasion of China 70 years ago.
Members of the Hong Kong-based Action Committee for Defending the Diaoyu Islands said they hoped to reach their destination by August 15.
It is the day the group prays for peace in commemoration of Japan's surrender in 1945.
Their second-hand fishing boat, the Diaoyu Island II, will set sail on August 12 or 13, depending on the weather and the state of the vessel's mechanics.
Last year, the boat stopped in Taiwan but no break is planned for next month's voyage to the eight uninhabited islands in the East China Sea, claimed by the mainland, Taiwan and Japan, which calls them the Senkaku Islands.
Committee chairman Raymond Chan To-wai said the date was chosen to remind the Japanese of the suffering inflicted on the peoples of Asia during the second world war.
