These type II submarine plans are here to give some indication only of the internal layout of UC-42. Bear in mind that the mine tubes took up the forward section of the sub, which is not shown in these plans. The six mine tubes were wet - permanently open to the sea - and in order to place 3 mines in each of the 6 tubes the top deck was raised forward of the deck gun. Also the forward torpedo room was obviously removed to make room for the mines. Two torpedo tubes were placed forward and completely outside the pressure hull.