Dorsal fins!!!

[Traveling Merman]

Hey guys, what do we know about dorsal fins? They look nice sure but I'm wanting speed out of a tail, how much drag do they create? Would a more ridged and less floppy dorsal be more aero-dynamic than a floppy one?.......and by that I mean dorsal fin!!!

[Kae]

Any extra fins will create more drag than a tail without. I think a Rigid dorsal fin would work much better than a floppy one though!

[Mermaid Veruliya]

My pet peeve is when dorsals go from butt to heel. Just because in the water when swimming, the knees bend and it makes it way more obvious and it's distracting. They look amazing for out of water shoots where the legs aren't bent, which I think really sucks, because I love the way the look out of water, but hate them in the water. For speed, yes any fin creates drag. I assume adding a dorsal is for aesthetics. So a smaller rigid one should meet your priorities of speed and aesthetic

[Anahita]

I'd say any dorsal fin that isn't selachimorpha/cetacean shaped is going to really drag you down. And even then, I'd pick one from one of their faster swimmers, not their slower movers - something like a Great White, Black-tip, or Hammerhead shape for selachii, or Bottle-nosed dolphin, Orca, or Spinner dolphin shaped for cetaceans.

Flowy fins that seem to be popular are very pretty, but their surface area and lack of structure creates serious drag (think of how a betta fish has to move compared to how a tuna moves)

[Mermaid Isabel(:]

I have another question to add. What if the dorsal fin is higher up near the butt. Does it make it uncomfortable to sit or would that make it rip off?

[Mermaid Veruliya]

A few mermaid here have no problems with their dorsals and sitting. Of course if it were super rigid, I wouldn't want to sit on it, it may be especially fragile to bends breaks and tears. Any fin needs to be treated very carefully

[New York Mermaid]

I have a unique dorsal which is a bendy spine with fringe I have no issues with drag

[Azurin Luna]

I have a hollow neoprene dorsal like a dolphin dorsal, it's high up on my butt, but when I sit down it harmlessly folds over and you don't feel any of it. My other dorsal from my second tail is made out of vinyl and so floppy that it falls over under it's own weight. This one really creates drag, while my dolphin shaped one doesn't

[Traveling Merman]

I'm wanting a silicone tail with dorsal like the mertailor makes only with the dorsal fin starting at the top of my bum and ending about an inch above my knees , what I would want is something in the dorsal to make it stiff but bendy if sat on.......... Would a segmented dowel rod with each segment attached end to end with tiny springs work? It would have I be in a hollow tube like cavity at the "front of the fin" where it first comes into contact with the water.

Thoughts?

[Anahita]

That's an awfully complicated and easy to damage design. And you run the risk of the weight of the silicone crushing it on its own. Plastic boning/heavy-duty zip ties has been suggested before in other threads; and it definitely has my vote, as it would be simpler, and more fail-proof.

Sometimes the simplest solution is the best one. I think this is the case here.

[Traveling Merman]

Would plastic boning not be too stiff in water and zip ties be to flimsy to hold the dorsal ridged in the water? Or no?

Pictures please! I'm imaging something like a chopstick when you say boning! Lol x

[Anahita]

Plastic boning and heavy duty zip-ties are essentially the same thing structurally. It's made for clothing and to be next to and conform easily to the body and is common in all types of costuming, from cosplay, to historical, to evening wear. A chopstick is nothing near these things. Chopsticks are usually wood, or rigid and hardened plastic and designed for moving food, which definitely wouldn't work for anything you want to put on your person when flexibility is necessary.

Here's some plastic boning, but really, if you just google it, you'd be able to see all the various types available, and where to buy it, what kind to use for what type of structured garment, etc. Same with zip-ties

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