Thank you for visiting the page! Ships with careful packing from Japan. Explanation U-Boat Type XXI and Type XXIII are submarines that have been in operation since the end of the war and are also known as electro-boats. Until then, submarines had to use separate engines, diesel engines on the water and electric motors underwater, and they surfaced and acted most of the time, diving only when attacking or escaping. XXI is equipped with a large amount of batteries and a newly developed underwater navigation motor.