What do cigarettes have in common with fins?

Terrestris fins are those that enclose your foot like a shoe or extend off the end of your foot. If open heel they require a heel strap or they will come off when you kick. They are not Force Fins. They might be the fins you are wearing in the water today. They are not the best for your use in water. To find out why, take this challenge to test the propulsive characteristics of your fins.

Force Fins have "an open foot pocket, that allows you to wiggle your toes, and cantilevers the force of the kick from the large muscles of the upper thigh." Wikipedia, swim fins, Force Fins.

Force Fins are curved, or have internal structure on the underside of the blade that recoils and responds with a SNAP when you kick. That recoil and snapping action throws water behind at a faster rate than you can kick with any other fin, and resets and recovers your leg. The result is more thrust, but it is the Force Fin that propels you. Your leg muscles are allowed to relax with each kick. To kick and relax is to kick with a power and recovery.

Kicking Force Fins is much more efficient and will burn less air, and assist in building strength and better for cardiovascular conditioning, than pushing and pulling, with your toes pointed, against a flat terrestris fin extending from your foot.

Terrestris fins are flat. Humans have more strength when kicking their leg forward than when pulling a fin backwards. The difference between terrestris fins and Force Fins becomes dramatic when you must kick fast, or when under extra load as when rescuing your poor dive buddy who was foolish enough to wear terrestris fins on a challenging dive. Your muscles are not designed to continuously push and pull against a strain inducing load, made heavier by water density.

Like smoking a cigarette, rapidly pushing and pulling against a terrestris fin will cause lactic acid to build up in your muscles, and you to huff and puff from oxygen depletion.

If your in-water journey is to be huffing and puffing, with muscles burning from oxygen depletion, then your terrestris fin, all other fin selection is vast. If you choose to be free as an aquatic being, fluidly and efficiently moving through water, then there is only one choice, one fin that frees you from your feet and lungs - Force Fin......For More Words of the Wise