There’s a reason the undulating movement associated with using a monofin is called a “dolphin kick” – a monofin is a variant of traditional swimfins that enables swimmers to move through the water quicker and with more maneuverability.
Underwater, monofin swimmers cut through the waves like dolphins, moving their shoulders and hips together while barely bending their legs to transfer all of the motions to the monofin. This “dolphin kick” enables swimmers to generate a substantial amount of thrust, allowing them to reach speeds over seven mph.
The monofin itself consists of a single surface attached to “footpockets” that contain each of the swimmer’s feet, and can be made out of glass-fiber or carbon-fiber, depending on a swimmer’s style. Monofins are deployed all forms of water sports, including freediving, underwater orienteering, and traditional swimming