Takeaki ENOMOTO, the Vice-President of Navy, who made sure that Yoshinobu TOKUGAWA left the capital for Shizuoka, went away form Edo for Ezo leading eight military ships on Kaiyomaru as a flagship from off Shinagawa on August 19, 1868, for the purpose of rescue of former retainers of shogun and protection of Hokuhen.
徳川慶喜の静岡下向を見届けた海軍副総裁榎本武揚は旧幕臣の保護と北辺防備を目的として慶応4年（1868年）8月19日に品川沖から開陽丸を旗艦に8隻の軍艦を率いて江戸を脱出し、蝦夷地に向かった。