View Full Version : Monofin question

12-20-2011, 10:56 PM
Ok so, soon after Christmas I will be starting on a new tail. I'm designing it after the golden tench, a fish I chose because it is native to the UK, especially in the north (go Scotland! Woo!). Also, it is a beautiful color that matches my hair and I feel that mermaids looks especially real when they sort of match their tail. XD

SO, I got myself a pair of speedo optimus swim training fins. I liked them because I'm planning on constructing a monofin with lexan and their short blades decreased the amount of material I have to cut off.

My question is this: How much of the monofin is actually useful? By that, I mean how short can one make a monofin with it still being effective? Would you still get propulsion if the monofin was only the top bit of the fluke and the rest something more flexible like office chair matting or even just neoprene? What do you think?

For reference, here are the fins I got: http://www.amazon.com/gp/product/B00070QEOE/ref=oh_o00_s00_i00_details (http://www.amazon.com/gp/product/B00070QEOE/ref=oh_o00_s00_i00_details(i) (i bought some used ones for less that $20, and that's including shipping!)

12-20-2011, 11:43 PM
Well, what I've found is that the larger the fin is, and the stiffer it is, the more propulsion you will get. That is why the thickest ones are made for sprinting. However, this also requires the most amount of bodily effort to achieve moving, so it can also put a big "ugh" on your fluidity unless you practice a LOT.

Any fins will get propulsion in the water, though. When I was at Weeki Wachee, they use fins almost identical to the ones you bought. and they are not even bonded togeter. They are just positioned in the tail. And I got around in the springs just fine - with the currents, turtles, fish, and everything. I probably wouldn't have tried free diving in the ocean using them - for that, I have my big 'ol Leaderfin, but if all you are trying to do is get around, and with the most grace possible, your fins should be perfect. :)

12-21-2011, 02:32 PM
Thank you so much! THat was exactly what I needed to know! I think I'm going to leave these fins as is and construct another monofin from the lexan Capt. Nemo style.

Capt Nemo
12-23-2011, 03:47 PM

Something you may want to try is moving the footpockets off the blade so that your toes and maybe ball of your foot are on the blade curvature. That will give a little more leverage and power. Most freediving monos have the feet off the blade.

Get 2 square feet of 1/8" gasket rubber per footpocket. It will give room for mistakes in cutting.

Methelene Chloride (solvent for welding acrylic/polycarbonate) may not be available in all areas, like California.

Once built into a tail, get a long metal shoe horn to help get the strap over the heel.

12-24-2011, 02:33 AM

Thank you so much! You are eternally helpful. I went back to the old site and found your post about making the Titania fin and it is super useful! I will be sure to take your advice. I live in Texas and we are pretty liberal when it comes to people being allowed things, so finding the welding solvent shouldn't be difficult. Also, that is a fantastic tip about the shoe horn. In my other tail, I ended up putting zippers at the ankle and hiding them with fins.

Mermaid Sirena
12-27-2011, 01:08 AM
When I was on the swim team we occasionally worked with these tiny little fins known as zoomers (don't know their official name) but the fin part only stuck out a inch or less from the edge of your foot but they still gave a pretty solid propulsion to your kick.