Why full foot on freedive fins?

[Altamira]

I have been looking at ads for freedive fins, and realized that every picture of freedive fins shows them as full foot fins. Is there some mechanical advantage to the full foot fin for freediving verses the open heel fins used by most scuba divers. Just curious!

 

[dumpsterDiver]

Good question... The difference is, as you observed, very dramatic. Full foot fins are most definitely more efficient and better for propulsion. In fact, the most efficient fins is a full foot, mono-fin..like a dolphin fin, but that is not so practical for spearfishing etc.

The full foot fin, is a little harder to get on and off, but it is also much less likely to get tangled in fishing line etc.. The heel straps (of an open heel fin) and the associated clips, can all collect fishing line, while a full foot fin is completely smooth on the sides and string or line etc. will just slide off it.

The freedive fins have longer blades. These make walking on a dive boat difficult. Freedivers, aren't wearing all the heavy scuba gear on the boat, so they are more manueverable.

The open heel, scuba fin allows the diver to wear a heavy neoprene boot (they have soles) which makes walking over rocks etc. practical. Freedivers generally wear neoprene SOCKS under the fins (no soles) and there is no excess room for a heavy sole. So if you have long trecks over rocks before entry, then a scuba fin might be more practical.

I have not used an open heel scuba fin for probably 4-5 years now. The increased effciency in the water, out weighs the disadvantages for me. I use the same fiberglass blade, freedive fins for scuba and freediving.

edit: I should probably add WHY they are more efficient. The full foot fin pocket, holds the foot firmly. the upper part of the pocket is somewhat soft and slightly flxible to provide comfort, but the sole of a good freedive fin is solid, inflexible and this combination serves to transmit power from the leg to the water more efficiently than a normal scuba fin. If a normal scuba fin delivered power more efficinetly, you can be damn sure freedivers would be using them. Thy are all about efficiency in the water- after all, they do it all on one breath. Incidentally, I fins a good freedive fin much more comfortable than an open heel scuba fin and a boot, they tend to wobble and tear up the tops of my toes.

 

[Chugwhump]

As DD said and a few other personal observations:
Less drag.
No moving parts.
Not the best for FEROCIOUS current, as they can pop off.
Great power return.
Less cramping.
Less crap to worry about.
I wear Mares Volo Race fins.
I am faster and more maneuverable than my pals who wear similar length fins.
I think less fatigue.
I wear a 1.5mm Neoprene sock with them for chafing and protection from the boat, the doodads on the shore, and because Rubber/vinyl burns my skin.

Chug
Used to wear Mares Quattros, but then my feet grew to a solid size 13.

 

[Akimbo]

There are a few open heal long fins. I know of Riffe and Imersion, but there may be others. I use the Imersion because all the full foot fins I have tried are far too narrow for my odd-ball feet. They do have a foot pocket that extends well under the heel that helps with efficient power transmission. I am a small guy and had to use the largest size due to width. I actually cut about ½" off the bottom of the foot pocket extension to reduce drag.

I noticed that Mako has a new adjustable Velcro Fin Keepers full foot fin made of Nylon webbing.

MAKO Velcro Fin Keepers

 

[Altamira]

Thanks to all for your inputs. This is the great thing about SB--a lot of really good information from people that actually use the equipment, and can speak from experience.