When choosing fins you need to take into consideration what they will be used for and in what conditions. The fins should be tight but not too tight just to provide you comfort when swimming. They should not be wide because they can hurt your feet or can be lost in the water. There are several types of fins 1) Open heel fins- universal fins that should be used with diving booties. They can be adjusted to several sizes. 2) Closed heel fins (slipper)- fins suitable for diving and snorkeling. 3) Blade style- suitable for diving in deep water or spearfishing 4) Short blade fins- suitable for pools and training the swimming technique. No matter what kind of fins you choose, pay attention to quality materials. The use of thermoplastic rubber as a part of the fins contributes to their robustness. The vents in their blade improve efficiency while maintaining the integrity of the stroke.