For immersion in cold water of water bodies of Russia, the divers typically use a "wet" diving suits, complete with which sell and special boots. For such equipment, you will need fins open toe and heel are fixed to the leg using adjustable mounts. For "dry" "gidikov" with bots these fins are also suitable.
Most divers prefer the warm waters of the southern seas, rich in fairy-tale beauty of the underwater world. In this case, select the closed fins at 1-1.5 size bigger. This will allow the fins to keep the leg loose enough not to sleep with her, do not RUB and do not restrict movement.
In that case, if you prefer a vigorous style of diving, a short but "fast" range, the sharp dip, select fins with greater rigidity. They will allow water to move faster, but will require large expenditures of physical strength. For this style suit and flippers with a longitudinal slit running in water according to the type of propeller, moving it back. Expending less effort, you will be able to travel long distances with a minimum number of movements of the legs.
For those who like to turn their swim into a pleasant and leisurely walk underwater, suitable elastic traditional shaped fins, not allowing to develop more speed, but provides comfortable movement without much effort. As for the length, then Snorkelling is a pleasure of swimming will be enough to last the length of 55-65 cm, but for spearfishing fins select a longer – 85-90 cm
Note that for ease of movement of center of pressure of water on the working surface of the fins should be as close as possible to the point of application of force by the foot of the swimmer. This is the case when the stretched legs and toes of the foot working the blade is made with feet the angle is 20-30 degrees. In a hard, straight fins, when moving in water the athlete have to pull your legs stronger while swimming can cause seizures.