The kick one does with the monofin is the dolphin or butterfly kick. It can be used for free open water swimming or in a pool for training.

Monofins were introduced in the USSR in 1972, by a Ukrainian finswimming club, and have been used for finswimming competitions since, allowing monofin swimmers to reach speeds of 12km/h.

Of all the swimming fins, this one is the most unique and more difficult to find.