Fins

Blades worn on the feet that convert leg power into efficient propulsion, available in open-heel and full-foot designs.

Fins are your propulsion underwater. Human legs are strong but nearly useless for swimming efficiently with gear on, so fins turn each kick into forward thrust and free your hands for instruments, lights, and reels. Good fins let a diver cover distance, hold position in current, and maneuver precisely with the frog kick, flutter kick, back kick, and helicopter turn.

The two big families are full-foot fins, worn barefoot or with thin socks and popular in warm water and snorkeling, and open-heel fins worn over neoprene boots and secured with straps, the default for cold water, shore entries over rocks, and drysuit diving. Blade designs range from long and flexible to short, stiff paddle blades that suit precise technical kicks.

Match stiffness to your legs and kick style: a stiff blade rewards strong slow kicks, while softer blades favor a faster flutter. Spring straps are a cheap upgrade that make donning open-heel fins far easier on a rocking boat.