Embodiments of the disclosure include a flotation device or watercraft propelled through the water using a lever powered propulsion system. A comparator compares the output voltage coming from the VRM to memory. The opposing second gripper devices are dippable into interspaces formed between the first gripper devices, and at least one supporting element is disposed in the interspaces for supporting leading corners of the sheets, the supporting element being disposed locally fixed on the first transport device. Consequently, it is possible to improve the linear response of a reproducing output of the magnetic head and to adjust an effective track width of the magnetic head.