Fins provide a powerful leg muscles can move you through the water. This is much more effective than swimming with your scuba divers with limited leg use who use their arms with special hand fins. All fins, regardless of style or features have pockets for your feet and blades for propulsion.Modern fins come in two basic styles: adjustable strap and full-foot. Adjustable fins have open heel foot pockets and adjustable heel straps, whereas full-foot fins enclose the heel and fit like rubber slippers.

Most scuba divers wear adjustable fins because you can wear wet suit boots with them. Also, most high-power fins appropriate for Bali scuba diving are adjustable strap types, though there are exceptions. Warm water snorkelers and scuba divers often prefer full-foot fins because they don't need wet suit boots.

Most modern fins 
use a composite construction, with foot pockets and heel straps made from neoprene rubber (or a similar mater-ial), and the blade made from an appropriate plastic. However, non composite, all-neoprene fins remain popular. Fins have several features to choose from, especially blade design features. 

Blade features include ribs, which add rigidity to the blade and act as vertical stabilizers vents, which reduce resistance to fin movement and increase efficiency and channels, which increase efficiency by guiding water smoothly over the fin. (You can have long, passionate debates with fellow scuba divers over which of these offers the best performance, but while this gives you something to do when you can't go Bali scuba diving, the reality is that all the top fins offer comparable performance when you wear-the best fin for you.)