The leading edge of slalom fins, mostly, is either straight or just slightly curved. Their profile ranges from flat to medium thickness; and their thickness distribution should allow high speeds. The rake angle will be around 7 - 10° or more depending on the length of the fin. In sum, a good slalom fin should deliver high speed, good lift and good manoeuvrability. With a flat profile and the right flex-twist properties, the fin will provide an excellent performance in high winds, limited only by the standard set by the sailor.
Mostly, the outline can be derived from an elliptic, trapezoid or a combination form of both designs. The average length ranges from 30 up to 55 cm.