Specialized types of swim fins:

Different types of fins have evolved to address the unique requirements of each community using them. Scuba divers, in particular, need large, wide fins to enable them to overcome the water resistance caused by their diving equipment; snorkelers need lightweight, flexible fins; ocean swimmers, bodysurfers, and lifeguards favor smaller designs that stay on their feet when moving through large surf and that allow less awkward walking on the beach. Other, more specific design trends are listed below.

Paddle fins:

These are the most basic fins—a pair of simple stiff plastic, composite, or rubber blades that work as extensions of the feet while kicking. Some paddle fins have a water vent through the blade, opening backwards on the underside and forwards on the upper side, as in the third image. As the hip joint is flexed, a jet of water blows backwards out of the vent in the fin. This type of fin is sometimes called a "jetfin"; but the name Jetfin is a brand name. Other paddle fins have convoluted channels and grooves to improve power and efficiency. Paddle fins are generally not the most efficient fins, but are widely believed to be the most versatile.

Split fins:

Some swimfins have the end of the blade split. In hydrodynamic principle, split fins operate similarly to a propeller, by creating suction and lift forces to move the swimmer forwards. Water flowing toward the center of the fin's 'paddle' portion also gains speed as it focuses, creating a 'scooping' or channeling effect. Split fins are sometimes called "Biofins", although "Biofins" is a tradename. Split fins are generally regarded as among the most efficient fin designs, although there is ongoing controversy among divers as to their versatility - many report that split fins cannot be used for frog kicks and are poor for maneuverability.

Force fins:

"Force fins" represent a type of fin that is only manufactured by Force Fin. They are radically different from all other fins - they have a wide upturned blade made of polyurethane, with a shallow V-shaped cut into the end like some fishes' tails. Force Fins are valued for their high efficiency and acceleration, but are often chided for their poor maneuvering characteristics. Also, for divers who wear neoprene wetsuit booties in cold waters, the negative buoyancy of the lightweight Force Fins is not sufficient to counter the positive buoyancy of their boots. This leads to a condition colloquially known as "floaty feet".

Freediving fins:

These are very similar to paddle fins, except they are far longer, and designed to work with slow stiff-legged kicks that conserve energy and oxygen. Though primarily intended for high efficiency at variable depths, they can still deliver impressive acceleration if necessary. The vast majority are made in the "full-foot" design with very rigid footpockets, which serves to reduce weight and maximize power. Freediving fins are commonly made of plastic, but are also often made from materials such as fiberglass and carbon fiber.