Since 1974, the Strontrace is held. Sailors compete with each other to sail from Workum via the IJsselmeer to North-Holland and back with a cargo of dung. Competitors of this legendary race may only use sail- and manpower. Thus, the historical route of manure from Frisian farmers to the Dutch bulb-best is simulated. To enhance the historic character even more, participating boats may only when they have a historical character, such as barges and skûtsjes.