Maneuverable Extended Tail Monofin Project! Almost Done!

[Kc-proart]

Hi!

I just joined this Mer-Network forum and have been reading up on the progress that others have made/been making on the “Extended Tail” project. I am a part time secretary and a full time professional artist. I have been independently studying hydrodynamics, bio-mimicry, and materials composition to figure out the engineering aspects for a, fully functional, extended monofin tail. I am not an engineering expert by any means. My knowledge extends only as far as my research can get me, without any formal training of course. I wanted to let you know what I’ve discovered and hopefully share in the excitement of having an extended tail that can be steered! I’ve learned through trial and error and extensive research! I am about 2 weeks away from testing the extended fluke portion of my tail before I begin adding the body and fin portions. I’m hoping that it turns out well...

I live in a land locked state where there might be a couple of merfolk in the state but I haven't met them yet. Rural West Virginia isn’t really known for merfolk! So, I’ve been working on this by myself and annoying my husband with information that he isn’t really following lol! He tries. I just wanted to talk about it with other mer-minded people. So here’s what I’ve done up to this point...

This was my initial idea and it was based off of a leafy sea dragon. My cat likes to help



This monofin concept was pretty but less practical and maybe I will re-visit the aesthetics later and make a tail based off of it but with improved support structure.



This was my initial concept for the extended tail and the support/bracing that it needs. Now, having looked over the H2O extension design and reading a thread where its design was discussed, I realized that the method they used was impractical for swimming for 1) any length of time & 2) Was an obvious and dangerous lack of maneuverability. It also didn't seem very fluid... Biological. The mechanical aspects where giving the motion a very stiff appearance. The other large issue with this was that a great deal of the energy and motion that the swimmers were exerting was not being translated to the fluke resulting in a loss of forward motion/propulsion. I wanted to add bracing of some sort and (as an attempt to lessen the appearance of the heal bump) had the main fin support arching downward off of the heals.

This did not work.



In an effort to make it more streamlined I also had the foot bars narrow before flaring at the top of the fluke. This ended up resulting in a loss of power from the feet to the fin. The concept for the monofin support section was to imitate nature. The hard line of a mono fin can be seen oftentimes through the silicone layers encasing it. especially when the fin is in flex. the silicone is just along for the ride freely flopping around. the support material mimics the cartilage that comprises a majority of fin support in fish. it has two major supports that branch out following either side of the fin. these are the largest and main supports these are essential for the rudder motion of the fin. the spines off of the base of the fin break up the hard line and provide extended support throughout the fin. This particular aspect doesn't change throughout revisions.

For the sake of not making this a really, really long post I am not going to add pictures of all of the revisions...



I was a fan of not locking in the heels. It would constrict the motions capable while swimming. I wanted to have the ability to stand up if I had to. The final version I settled on and began making was this one. I made a, light bulb looking, open space in the top of the monofin. This is so that the two main supports can flex off of the connecting portion of the support in the middle. This allows a fairly large ruddering motion to occur with as little as 2 inches of movement up and down of the two main bar supports coming down from the feet this enables the feet to have to exert less force to make the turn occur in the water. This means less fatigue and more swim time! Yay! By straitening the bars coming down off the feet it provides a direct rout for the motion and energy from the legs to translate to the fin, but with the loss of power being cut in half. This design works and I have been working on making the different pieces individually to make it easier to handle. The fluke if 4 feet wide at the widest point. This is because I am a fairly large figured person and I want the power for river swimming against currents. I have done a good deal of river swimming as it is the closest body of water that I can swim in and have been swimming with a monofin for multiple years. I do not recommend this fluke size for a smaller figured person with less developed calf muscles. It could cause strains and injuries if you don't work up to an extended fin because of the added effort it takes to swim with it.

Here is what I have made so far. I look to finish the fluke portion and test it, in a pool first, within the next few weeks.



The cartilage support starting off.



First layer of silicone to encase the support structure.



My cat helping me... it is really rough and not pretty but I am just trying to get it together for proof of concept. I can refine it later and make it pretty.



The support bars before I attach them to the fluke.

I look forward to hearing your opinions and talking tails! Thank you so much for reading my post!

Kelly

[Merman Storm]

I don't know if you have run into it yet, but you may also want to look at the Lunocet. It is a commercial extended monofin. It has one aspect that you want: It is very, very fast.

Also, for anyone who does not know: The H2O tails were filled with silicone foam between the wearer's skin and the tails outer skin, hiding heals and whatnot. Silicon foam is open cell, so it fills with water once you get in.

P.S.: can you really point your toes like that? I sure cannot.

[Sam is here]

that looks great so far!
good luck!!

[Mermaid Jaffa]

I think a fluke that wide needs a professional monofin. One that has a rating of medium to hard, otherwise it'll cave in when you swim.

[Kidiu]

This is really well thought out, I’m glad that someone is trying to solve the maneuverability issue! I’ve drawn up my own concepts for an extended tail, but I really like your ideas and I’m excited to see how your design works in the test swim.

[Mermaid Kassandra]

Your work is really amazing!
I am really curious about seeing the result of your research and the entire tail completed

Also, as merman Storm pointed out, I think you should look at the Lunocet it may help a lot

Another thing I noticed is that you draw your feet like a ballerina would keep them, but for experience in the water while swimming that is a very stressful position for them, as an advice you should keep in consideration that you might want to be able to stay in a “rest position” also to burn less oxygen

[Kc-proart]

I don't know if you have run into it yet, but you may also want to look at the Lunocet. It is a commercial extended monofin. It has one aspect that you want: It is very, very fast.

Also, for anyone who does not know: The H2O tails were filled with silicone foam between the wearer's skin and the tails outer skin, hiding heals and whatnot. Silicon foam is open cell, so it fills with water once you get in.

P.S.: can you really point your toes like that? I sure cannot.

Thank you very much for the Lunocet referral! It is a beautiful design and if I could afford one I would love to give it a try I thought of trying the neoprene foam, However I found that it took a long time for it to dry out. I was worried that this would lead to mold and mildew forming inside the finished tail. There is a "Quick Dry" foam that I have tested with my other monofin to remove the heel bump and it worked really well. Quick dry foam is used often for marine and boat cushions as it is also an open cell foam but with the ability to let water pass right through it. This let it dry out quickly after use.

As far as my toes... I learned to swim with my monofin like that from the beginning so I didn't really know that others didn't swim with their feet not pointed. I still have much to learn!

Thank you very much for the feedback!

[Kc-proart]

I think a fluke that wide needs a professional monofin. One that has a rating of medium to hard, otherwise it'll cave in when you swim.

I agree this will fold if I try it as is. The layer you see right now is only half of the silicone and support that goes into this. I am currently working on adding the other half that will give much needed stiffening and support Thank you very much for pointing that out!

[Kc-proart]

This is really well thought out, I’m glad that someone is trying to solve the maneuverability issue! I’ve drawn up my own concepts for an extended tail, but I really like your ideas and I’m excited to see how your design works in the test swim.

Thank you so much for the encouragement! I will try to get my friend to take a video of the initial test of motion and maneuvers in the pool once its ready! It will help me see what adjustments might be needed before adding the rest of it together It would be fun to see your concepts some time also!

[Kc-proart]

Your work is really amazing!
I am really curious about seeing the result of your research and the entire tail completed

Also, as merman Storm pointed out, I think you should look at the Lunocet it may help a lot

Another thing I noticed is that you draw your feet like a ballerina would keep them, but for experience in the water while swimming that is a very stressful position for them, as an advice you should keep in consideration that you might want to be able to stay in a “rest position” also to burn less oxygen

Thank you very much for your interest in my project! Yes, I did take some inspiration from it when I started. It truly is a marvelous design!

I can't thank you enough for the advice on the feet. I didn't know about it burning more oxygen to swim with them in that position! I'm going to the pool tomorrow and will definitely try relaxing that position a bit more

[Mermaid Kassandra]

Thank you very much for your interest in my project! Yes, I did take some inspiration from it when I started. It truly is a marvelous design!

I can't thank you enough for the advice on the feet. I didn't know about it burning more oxygen to swim with them in that position! I'm going to the pool tomorrow and will definitely try relaxing that position a bit more

You’re welcome
Here in the community we are here to share and to help so it was a pleasure!
Let us know how the test will go

[Merman Storm]

A few observations on foot angle.
Most monofins are parallel to the sole. This would seem to assume you can point your toes quite well. But there are some "angled" monofins where the blade it set at an angle to the sole. 20 to 25 degrees seems to be typical. The Lunocet is in that range. Also, the extended monofin built into the H2O tails have the monofin angled relative to the foot sole.
Ive been bending FinFun inserts 20 to 30 degrees, and found they work much better for me. (Last I checked, the best I could point my toes was to get the sole to 30 degrees. I really need to do more stretching, but my ancient body is slow to respond.)

Now, about turning: My technique is terrible, and I could use some hints. I turn in one of three ways: Rotate on my side and bend at the knees, bend a little to the side at the waist, and some sort of "flat turn" where I am not quite sure what I am doing. But it seems like I'm doing something that makes the monofin want to slip to the side, turning me. Is this what do you mean by "ruddering"? Can you post a link that describes it?

[Rett]

I will always encourage anyone attempting to tackle the elusive extended tail! I wish you the best of luck, and will surely be following this thread!