When the new government army occupied Edo, Kaiyo Maru Warship, Kaitenmaru Warship, Banryu Maru, Chiyodagatamaru led by the former retainers of the resistance force who were dissatisfied with the treatment of the Tokugawa family by the new government, including Takeaki ENOMOTO and other four transport ships (Kanrin Maru, Chogei Maru, Shinsoku Maru, Mikaho Maru) (the first Japanese ship ever to cross the Pacific) which accommodated the soldiers of rikugun (army) including commando unit escaped Shinagawa oki (coast).
新政府軍が江戸を占領すると、徳川家に対する政府の処置を不満とする榎本武揚ら抗戦派の旧幕臣に率いられ、開陽丸、回天丸、蟠竜丸、千代田形丸は、遊撃隊など陸軍兵を乗せた運送船4隻（咸臨丸・長鯨丸・神速丸・美賀保丸）を加えて品川沖を脱走。