insulating element from mineral fibers for shipbuilding with an insulating element in form of a plate or roll felt for shipbuilding the composition of the mineral fibers of the insulating element points an alkali / alkaline - earth mass ratio of the fiber structure of the insulating element is determined by an average geometrical fiber diameter of ≦ 4 μm and a surface weight of 0 . 8 through 4 . 3 kg / m 2 and a binding agent portion above 0 . 5 until 4 weight %.