Underwater diver propulsion equipment

Swimfins, swim fins, diving fins, or flippers are finlike accessories worn on the feet, legs or hands and made from rubber, plastic, carbon fiber or combinations of these materials, to aid movement through the water in water sports activities such as swimming, bodyboarding, bodysurfing, float-tube fishing, kneeboarding, riverboarding, scuba diving, snorkeling, spearfishing, underwater hockey, underwater rugby and various other types of underwater diving.

type of rideable submarine used as secret naval weapons in World War II

thumb|A freediver using a monofin thumb|Herbert Nitsch wearing a monofin at the Cyprus BIOS 2004 Freediving Open Classic

powered device for diver mobility and range extension