Best shape for propulsion?

When comparing monofins to tail flukes of both mermaid tails and actual fish flukes I noticed quite a difference.

• Monofins are usually rounded on top, have a width-to-height ratio around one (they are roughly as high as wide) and have a straight bottom edge
• Fish flukes are also rond on top, but are mostly broader than high and have a somewhat curved bottom edge (either half-moon-shaped or otherwise curved)
• Mermaid tails appear to be more fish-like when not build around a given monofin

The question is, which shape would give the best push when used with a mer-tail?

So, what kind of experience do all of you have with different shapes? Are there some that work much better than others or is it more or less irrelevant in a tail, so one should put the aesthetics first?

Interesting question.

I've swum with 5 different monofins so far.
One of them is sickle-shaped (almost like a dolphin), and it gives the least propulsion of all.
While that might be also due to the material it's made of rather than the form, you have to keep in mind the conventional monofin is supposed to shovel water and provide you thus with propulsion.
This means the more water you can shovel ergonomically, the better the propulsion.

Fish caudals and whale flukes work with a different principle; they channel the water around their shape and provide an uplift.
The only monofin with the same principle is the new Lunocet, which I sadly haven't had a chance to get yet (planning to).

Which means the answer to your question is probably; the larger the monofin blade (ergonomically speaking; too large and you won't be able to move it), the better your propulsion.
Fish-shaped monofins won't give you as much push. Same if you cut a commercial monofin too much.

As cool as it would be to have a fin looking like a thresher shark's, you won't be fast with that at all unless you make sure it can function like the Lunocet.

I remember hearing about that a year or two ago. I would really, really like to know how it feels to use. Someone posted in the monofin thread recently saying that its a very different experience, and more technically demanding because you need a strong dolphin kick.

I agree with caltuna that there are major differences between fish and dolphin locomotion. I think its pretty complicated.

I also want to add that I think more rigid monofins like fiberglass are considered better for propulsion than flexible ones like the rapid, which is made of thermoplastic. I don't know whether that's true.

I'm pretty much a n00b when it comes to monofin swimming, having done it twice thus far, but I did notice the Hydra gives pretty darn good propulsion, especially in comparison to the Finis I also got to try. It's rigid but flexible under water, and is clear so you can build a lot of tail shapes around it.