One theory says that it was a huge ship of 139 cubic meters in loading capacity with 21.8 to 23.6m in length and 12.7m in width, equipped with three ozutsu (Japanese artilleries) and many odeppo (big guns) and the surface of the body was tacked with iron plates 3mm in thickness.
一説には大筒3門の他、大鉄砲を多数備え、船体に厚さ3mmの鉄板を鋲で貼り付けた長さ12～13間（21.8ｍ～23.6ｍ）、幅7間（12.7ｍ）の1500石積みの巨船といわれている。