DIY mirage drive turbo fin made out of kydex

I had a spare 12" x 12" sheet of 0.080" kydex, and decided to try to make a Hobie turbo-like fin out of it. I heated the kydex with a heat gun, and formed it around the stainless mast. The rigidity of kydex is supposed to be similar to PVC of the same thickness, and kydex is very easy to form when heated and it's impact resistant (it's often used for holsters and sheaths, for example).

I was not expecting it to work well, as I've tried semi-rigid plastic before (as have other experimenters on YouTube), and it failed badly, in the sense of being much harder to pedal and yielding way less power, as compared to real Hobie fins. So, I was pleasantly surprised when my kydex fin worked very well. In fact, I could not tell the difference between this and standard Hobie fins.

I suspect that the key to success is the bungee cord that I used to connect the fin to the Mirage drive, as opposed to making a rigid connection. In the video, you can see the overall action of the kydex fin is very similar to the Hobie fin, due to the added flex provided by the bungee cord.

Not sure if this will be a long-term solution, but it I plan to do some more experimenting to find out...

https://youtube.com/shorts/1uiTd46DlFA

Hey, that looks pretty good.  Nice job.

Forgot to mention that I don't think there is anything magical about kydex in this application, as any semi-rigid plastic should work.

Also, I pedaled it around the harbor for about an hour when I made that video. Today, I took it out for a spin on my AI (sailing and pedaling in SC), and it's still working great...