We do our Good Samaritan bit and tow this yacht out of the lock as its engine has died. The Wasserpolizei are waiting, glower at us and take photos as we deposit the ailing yacht next to a pontoon and carry on. We find out later that you need a licence to tow in Germany. At least the yachtys are happy with us. They catch us up later having fixed the problem and dangle two bottles of beer on a boat hook over the canal for us to grab.