Original Jet Fins

[Sam Miller III]

@John C. Ratliff

John'
I also have Duilio Marcante's great book This Is Diving, A Complete Underwater Course, I highly recommend it to all'
I think I even have a spare packed away -- We are remodeling everything is a mess.

Your fin modification & experiments remind me of Herb Van Der Pol, LA Co UW instructor who modified the Plana fins to develop the Power Plana for at that time for the now defunct company called Winoka.

Herb experimented with the Planas in his bath tub, tested in the acific Ocean and finally perfected the perfect fin .

Herb patented them Winoka adapted them - put them in their inventory --All the original Power Planas have "Herb Van Der Pol " embossed on the bottom of the fins.

They were way ahead of the curve for several years.

I have heard rumors or urban legends of SoCal divers bolting truck mud flaps to the bottom of Churchills but never personally knew any one who modified them or I never saw any modified Churchills.

Keep up the good work-- always enjoy your very informative posts

Sam .

 

[David Wilson]

View attachment 488775
I have a book, This Is Diving, A Complete Underwater Course, by Duilio Marcante, Copyright United Nautical Publishers S.A., Basel, Switzerland, 1976. In it there is a photo of a free diver using the Beuchet Jetfins. What is not shown on David Richie Wilson's catelog above is that these closed-heel fins were also open-toe fins.
SeaRat

I too have a copy of the book, John, which confirms that you are right that Beuchat produced an open-toe version of the Jetfin in the late 1960s and early to mid 1970s. This version appeared in Beuchat's French (Dispositif d'accélération de poussée pour palme de natation) and British (Improvements in or relating to swim-fins) patents of 1971. The British patent drawings below:

And here is a picture of a pair of closed-heel and open-toed Jetfins like the ones pictured in the Marcante tome:

However, the story doesn't finish there. Here's a 1969 Jetfin ad from the wonderful bibliotecadiunapneista.it site:

Note how this version has two jets instead of the usual three through the blade.

And there's more still. Here's a version with a closed heel, an open toe and the buckle points for a heel strap:

And here's another closed-heel with heelstrap version with a closed toe. Note the different blades:

It would appear that Beuchat developed many full-foot Jetfin designs, realising perhaps that Scubapro had no intention of releasing a closed-heel version of Scubapro Jet Fins and that Beuchat could therefore continue making and selling their own Jetfins in a variety of versions for the European market.

 

[Popgun Pete]

The first pair of Jetfins that I ever saw (1966) were the Beuchat model with an adjustable heel strap and a full foot pocket that the instructions said that you could use with or without wetsuit booties. This was achieved by rolling the heel inwards and under the boot heel, or cutting along a mold line in the heel area that would snip the upper heel section off thereby transforming them into open heel fins. I bought them when most other fins were a quarter of their price ($22.40), but they were the only pair in stock having been bought in as a sample at a now defunct city department store and there were only one or two other pairs in a rival major sports store (no dive shops). Fortunately they were all my size and I wore them without any boots. Slow cruise was their strength as they pushed you along very easily, but when driven at a high kick rate that although they made the water boil in your wake they were not much better than anything else. However most diving is done at a relaxed cruise rate and they had evidently been tuned for exactly that type of service. My next pair I purchased in 1974 and they were full foot pocket and much longer blade with an open rather than closed toe. A pair of open heel Jetfins were purchased for scuba and use over hard sole diving boots, a pair of Super Jetfins for spearfishing with very long blades, full foot fins that had tri-vents but no real blade overlap as is usually a feature with Jetfins, and lastly a recent pair of open heel Jetfins with spring heel straps which all together span my fifty years in and under the water. I still have all of them, but the older fins eventually softened and showed age cracks as the rubber began to deteriorate as happens with all rubber dive goods eventually and thus they were replaced.

I never liked the Super Jetfins as their long blades seemed to be an attempt to pander to the long fin blade market that was just turning to non-rubber blades and it seemed that their "jet section" was just a token feature as with no real blade overlap with a big entry portal and small outlet portal then no jet action was possible over the rear face of the descending and very long blade.