For this, the hulls in the lower area were equipped with the keel fins typical of beach catamarans. The hulls of the Topcat catamarans are very similar to the design of the Tornado as well as the Dart.
The ability of the Topcat to sail in very shallow inland waters is unusual, as it has little draft and can still be steered when the oars are retracted at the level of the keel line. The Topcat is very suitable as a catamaran for coastal waters with waves. The equipment carried can be stored dry in the two storage compartments with screw locks.
For safety reasons, capsizing lines are attached to the front beam, which allow the catamaran to be easily straightened after capsizing. Also new is the divisible and freely rotatable mast and a liftrudder, in which the rudder blades do not have to be laboriously folded up in shallow water, but simply slide up through the rudder jaws after pulling on the line provided for this purpose. The two hulls are only placed on the two transverse profiles and are stably held together by a trampoline stretched between them. This is a compromise between the necessary lateral stability and maneuver agility. In order to offer enough lateral surface despite the lack of swords, the profile of the swimmer towards the keel line was chosen to be very narrow and deep. With Topcat catamarans there is no need for a large boom, swords and complicated trim mechanisms such as rigging screws. Usual catamarans were rigged like sailboats of equal size. Among other things, due to the division into the various sub-classes K1, K2 and K3, the necessary number of the same boats in the ranking list is not achieved. In Germany, the class has not yet been classified as worthy of the championship by the German Sailing Association, as the DSV championship regulations in Section 5.1.1 require at least 60 boats in the ranking list and the ranking system in Section 5.1.3 10 boats in a race. The first world championship then took place in Torbole on Lake Garda in September. In 2005 Topcat K1 was recognized as an official ISAF regatta class. In the same year the first European championships took place in Brenzone on Lake Garda with 44 participating boats from five countries.
In 1983 the International Topcat Class Association (ITCA) was founded after the national one. The first Topcat stations are set up on Lake Garda. Training courses are held within the framework of the Association of German Sport Boat Schools (VDS) and the Association of German Windsurfing and Sailing Schools (VDWS). This made it possible to organize numerous regattas in which absolute regatta novices could also take part. The German Topcat class association was founded in 1981 from among Topcat sailors. It had a mast height of 7.00 m as well as a jib with 3.6 m² and a main sail with 11.2 m² sail area. In the following year, the first Topcat catamaran appeared, a 4.80 m long two-hull boat that was only held together with plug connections. In the same year TOPCAT GmbH was founded. In 1976, the prototype was first fitted with a new type of rudder by Klaus Enzmann, for which a patent was applied for, along with other equipment features. In 1975, Klaus Enzmann, the designer of the catamarans, built the first swordless prototype without rudder, in principle similar to the Spanish "Patin-Vela", but improved in details.
Simplification of existing constructions.easy transport on the roof of an automobile.trailerable (width less than 2.55 m according to StVZO ).Manufacture of the boat hulls (floats) from glass fiber reinforced plastic (GRP) (as usual in boat building).Their idea was a sport catamaran with the following features: In the mid-1970s, two German sailing rivals in the A-Cat catamaran class, Bernd Breymann and Klaus Enzmann, found the cumbersome transport and assembly of the sport catamarans unsatisfactory.