Losing the Kaiyo and having allowed the new government forces to obtain the Kotetsu, the Tokugawa Navy, which used to be known as the largest and strongest, had now become unalterably inferior and substantially lost marine control.
開陽を失い、新政府軍が甲鉄を手中に収めるにいたり、最大最強を誇った徳川海軍の劣勢は決定的となり、事実上、制海権を失ったのである。