The right rake angle is the key to this design: Seaweed, plastic bags a.s.o. simply slip past.
Additionally, the rake angle ensures smooth entry into turns.
The material, the slim profile and the efficient shape make them very fast designs.
Their areas are quite large offering enough lift for easy planing.
The new Weed Slalom fins have an even slimmer profile to reduce their resistance and increase their performance.
Also, note the enormous length and area of these fins; there are not many weed fins that big available on the market!