A group of warships appeared off the coast of Uraga on June 3 (July 8) and to the Japanese people who spotted them, the ships were vastly different from those of the Russian Navy and British Navy, which had visited Japan in the past.
しかし、6月3日（7月8日）に浦賀沖に現れ日本人が初めて見た艦は、それまで訪れていたロシア海軍やイギリス海軍の帆船とは違うものであった。