Invented in 1936 by the world swimming champion Owen Churchill, modern fins take their shape from the tail end of dolphins. Since the middle of the 60s, fins have been made in a lot of various shapes, colours and have been hardly studied. Fins are generally made in natural rubber that comes from Indonesian forests. The price of fins has been rising for the last ten years.

           There are a lot of different shapes available for fins and all these shapes come from the tail end of dolphins' fins. That is why the shape doesn't have an important influence on propulsion. The choice of a shape must therefore be linked with your riding style (your stance) : for a prone rider, choose stiff fins but for a drop knee rider, choose a fins that is not too large and too long. For the rest, it depends on your preferences.

           This is the stiffness of the front part of the fin (the sail). This is this part that give you the acceleration. A large and flexible fin will give you quite a good speed; it will be less tiring but you will have a bad acceleration (for example during the take off). On the contrary, for a better acceleration, you have to choose stiff fins but you will need more power to swim (that is why these type of fins are not for beginners).

           You must choose fins in which you fell yourself good. Fins are not like shoes : it is not necessary that your toes touch the end of the fins. In fact, the strap must be tight and the fin and your foot must be interdependent, otherwise you will probably loose on of your fins in heavy waves.

           Fins are made with natural rubber and the friction between the fin and your foot will lead to small cuttings or blisters. To avoid that you can simply use socks or neoprene socks to protect your feet. Moreover, natural rubber is fragile so you need to clean your fins with fresh water after every use.

           You need to know how to use your fins before going in the water. You must avoid small movements that will not give you any thrust (and that is tiring). Then, you should not hit the surface of the water : that is a loose of energy. What you have to do is big movement in the water. Moreover, swimming with fins can give you some cramps; to avoid that, just drink a lot of water (between 1.5 and 2 littres per day).

           The size of fins are given in American values. Here is the conversion between American and French values :
34-35 : XXS or 1-3
36-37 : XS or 3-5
39-40 : S or 5-7
41-42 : M or 7-9
42-43 : ML or 8-10
43-44 : L or 9-11
45-46 : XL or 11-13