Human beings who love the water have long envied the fish their fins, which help them glide through the oceans with the greatest of ease. Even the genius inventor Leonardo DaVinci was captivated by designing fins that would aid humans while swimming.
Today's swimming fins are fashioned from plastic or rubber material in the shape of a flipper or fish fin and are worn on the leg or foot to enable faster and more agile movement while swimming, underwater scuba diving, body surfing or river boarding. The relatively small shape and size of most human feet doesn't provide enough energy to thrust the body quickly through the water, so wearing swimming fins accomplishes that task.
Not all fins are created equal. Different swimming fins have been designed for different purposes while in the water. Scuba divers need large and wide swim fins to help overcome resistance in the water while diving in deep water carrying heavy scuba equipment. Lifeguards patrolling the beach opt for smaller swim fins that can help propel them quickly through the surf in the event of emergency. Those who enjoy snorkeling opt for the most lightweight and flexible fins on the market.
There are two main styles of swimming fins, full foot and open heel. The full foot swimming fin is designed to fit over bare feet much like you would wear street shoes. Open heel styles attach to each foot with a strap and since they can be worn over boots, they are commonly used by divers.
The most basic style of fin to use for more power while swimming is the paddle fin, which serves as a simple extension to the leg muscle, providing more thrust and forward motion while kicking in the water. Vented fins are also popular for swimming, a more recent invention featuring vents that allow for some water passage through them for increased efficiency while the swimmer is kicking.The split fin, as the name implies, features a split blade end and works on the same principle as a boat's propeller to create suction that pulls the swimmer along more easily and with less effort, a model used by both swimmers and snorkelers. Free diving fins are very long versions of paddle fins favored by deep water divers because they help the diver conserve energy and oxygen while using slow stiff-legged kicks.
After putting on your swimming fin of choice, keep your legs well below the water level and use a leg movement like marching to propel you along without moving your arms. Swim fins are most effective when you extend your feet and kick your entire leg rather than just from the knee.