asymmetrical fin id question

[Nemrod]

Fortunately I have had mine for a while. Good thing because I would not pay 128 dollars for them. They are a fun vinage fin but compared to the famous and all conquering UDT they do not compare. N

 

[John C. Ratliff]

I agree, Nemrod. That's why I didn't keep Dad's fins (I had some Duckfeet fins). That and the fact that his fins were deteriorating.

Patents make interesting reading. Here is what Mr. Churchill said in the patent:

...Due to the flexibility of the devices it will be found that the user is able to walk with comparative ease and unless the surface be especially rough or sharp, such as from rocks or glass, no injury to the devices will result...

...I claim:
1. A swim-fin of resilient material, adapted to be mounted on the foot and embodying a hydro-dynamic fin shape comprising a heel gripping section, a central section forming a pocket to receive the forepart of the foot, and a toe extension web containuing the natural wedge shape of the foot, the toe extension web having one side diverging with respect to the other toward the free end, and said end being diagonally formed whereby the outer side is longer than the inner side, the central section and the toe exteension having a gradually increasing flexibility toward the said end.

2. A swim-fin of resilient material, adapted to be mounted on the foot and embodying a hydro-dynamic fin shape comprising a heel gripping section, a central section forming a pocket to receive the forepart of the foot, and a toe extension web containuing the natural wedge shape of the foot, the said heel gripping section, central section and toe extending web having one side diverging with respect to the other from the heel toward the free end of the toe extension, the wedge being longer along the outer side than on the inner side, the end of the toe extension being substantially diagonal from the shorter side than on the inner side, the end of the toe extension being substantially diagonal from the shorter side to the longer side, and marginal reinforcements aloong the said sides whereby the fin is rendered more fdlexible in the region of its medial longitudinal line than along its sides, tending to cup under resistance of water and displacing water with a propeller-like thrust when moved at right angles to the normal plane of said fin...

The interesting thing to me, that I just realized, is that he also patented the "scoop" action I've been interested in for so long.

Below is a photo of the fins worn by a Navy diver as depicted in the book Skin Divers In Action by Erik Bergaust and William Foss, G.P. Putnam's Sons, New York, 1965, page 22.

 

[duckbill]

Thanks for clearing up which side is which. I've been wondering for a while, but had always leaned the way you have all said is correct.