As the search for speed has initially led to extremely thin, lightweight but durable little boats, minimum thicknesses have been introduced (about 10mm minimum plank thickness, minimum dimensions and maximum distances for keel and frames) from the 1932nd
The evolution of the free Zwanziger has created extremely slim, elegant boats. A typical Twenties Rennjolle is over 8m, at about 1.70 m width and low freeboard, but dimensions vary greatly, with some copies 7m or over 9m in length. The rigging, although exempted from the class rules was traditionally Gunter and mainsail with full battens. For a long time the twenties were the fastest ships ever, and legendary triumphs in Cento Miglia, the famous endurance race could still be had well into the 50s on the lake.
Zwanziger racing dinghies were first built in the 20s in larger numbers and reached their heyday in the period before World War 2, but there were mainly in southern Germany, a number of new builds in the 50s (sail numbers to about 517) were added to the class by introducing modern unit dinghies (FD) then coming to a halt. The problem has always been the specialization that resulted from the different designs, so depending on the wind conditions one or the other boat has an advantage.
Mid 70s flickered interest in the Z-racing dinghies, from Austria (Mondsee, Grundlsee), the Chiemsee and Norddeutsche areas (Ratzeburg Lake, Steinhude) again and has since led to regular racing activities. A Class Association was founded and the building codes modernized. Today the twenties are sailed with a modern Spinnaker and two men in harness. The old idea of experimenting with forms is alive, since 1980, there are always new builds, of which not at all able to enforce immediately against the old ships. but the fascination remains speed and fine wood as a building material.