Tri-split fins .. soon to appear?

[BKP]

I have a question for the people who use split fins. I use a pair in the local quarry and they do fine. When I used them in the ocean with a current they did not do well. This is why I dont like them. My Jetfins do good in the ocean. So how do I make my splits work in the ocean?

Close your eyes, and pretend you're still in the quarry...

Seriously... if you're having issues in current with splits, chances are you're still kicking as if you've got a paddle fin on, using a wide kick flutter, which defeats the purpose of the splits. A modified flutter, very short stroke, keeping your legs and body in a very low profile against a head-on current deploys the fins the way they were designed to use, and reduces the overall drag of your legs trying 'push' you the way you would with a paddle.

The first time I actually settled into this kick in current, I could feel much of the resistance diminish. It seemed to 'click,' and the light bulb went on... The fact that I could also slow down and frog kick, and any cramping became a memory, was icing...

It's not rocket science... it's not pseudo science... it's a simple immutable concept...

 

[Pullmyfinger]

Ahh.. Jet Fins. Introduced in the late 60's.

Water hasn't changed since the 60's has it?
I don't care what people use. I bought Jet's on the recommendation of a friend when I first started diving, and haven't tried or seen anything that has made me want to change fins. I imagine if I had started out with split fins, I'd be just as happy with them.

I use Mares freediving fins for freediving, and Jets for scuba diving. I'm not about to start spending money on more fins just for the sake of looking for something different, when I have fins that do the job.

There are too many other things out there that cause me to spend money, fins aren't one of them.

Once I find something I like I stick with it. I still carry the same pocket knife that I bought about 15 years ago, no need to buy another one.

-Mitch

 

[Pullmyfinger]

That's a fact BKP,

Everything has it's own sweet spot, modify your kick to fall into the fins' sweet spot. Don't overpower them, and they'll all work great.

-Mitch

 

[pjones]

I'll throw this out one more time. How many paddle steamers do you see out there today? None but for casinos and Disney World. Who'd of thought that a little propeller spinning under the hull of a boat would be more efficient than big stiff boards pushing water.

This isn't the first time i've seen this analogy used. I just don't see how this analogy works...

First, I don't see the similarities between the design of a propeller to the design of a split fin

Second, I can't see how the operation of a paddle blade resembles that to the operation of a propeller because of the environments they operate in are two different worlds.

Third, I see paddle blades all the time in my line of work. They transfer air (a fluid) quite efficiently...

Lets explore #2 a little more. A paddle wheel blade must break surface tension of the water upon each and every stroke. This greatly limits the RPM that the blades can operate at because of vibration issues (amongst others) and that limits the amount of work that can be preformed with this style of blade (which is most probably the reason it has disappeared from boats). Paddle fins however, are submerges in fluid constantly throughout the kick cycle just the same as split fins are, just the same as a propeller is. In order for this analogy to work we would need to completely submerge the paddle wheel blades in water throughout the entire stroke or run them both in the air, just as the splits and paddle fins are used in similar environments. This of course changes the operating characteristics of the paddle blades as they are no longer pushing on a denser medium to provide propulsion, they are now operating similar to a centrifugal system of which the product would now need to be collected and directed before it would provide any thrust again. This is all in the assumption that we are actually able to find similarities between blades vs fins vs propellers...

I have no problems with split fins or paddle fins. I think people should be free to use whatever works for them, but, I would like to see people try to stick to analogies that compare apples to apples a little more closely...

Just my two cents...

 

[Frosty]

Hey guys I don't know any of the fancy tecnical stuff about fins.
What I DO know is that my wife and I did a mixture of snorkling and diving in the sea very recently.we took three pairs of fins with us. I have traditional "board" fins my wife also has a pair but recently we invested in a pair of split fins for her.
both of us wearing the traditional fins I can launch harder from a dead stop than her and get to a faster top speed. I also find turning a lot easier.
Now with her wearing split fins boy ohh boy did things change.I'm now struggling to keep up off the mark and she can turn on a dime.I think they seem to loose out only once you really start motoring along but frankly she doesn't have the leg strenth to overpower the split fins.
I wont buy a pair for myself but for her they are perfect.

 

[Crush]

It's not rocket science... it's not pseudo science... it's a simple immutable concept...

The fact that fins can move you forward in the water is real science. However, this:

is pseudo-science. The article where I first saw these images is located here: http://www.scubaboard.com/forums/fins-masks-snorkels/325435-split-fin-physics.html .

If you use splits and they work well for you, I am not arguing with you. It is possible that I might find them more efficient if I learn to paddle differently. I was invited to comment on my first exposure to splits and did so.

 

[Brendon]

Tri Fins... I bet those will be expensive... Cant wait to sell them to newbies 399.00 they will buy them all day long, because the blogs will say something like their the best... JK...You kick and you move its that simple... Why make it more complicated with pseudo-science? Why dont we all just strap a couple of DPV's to our legs and become the laziest divers this country has seen yet... It will be hard to call it a sport then. Lets go back to the double hose regulators, modify them to feed us and deliever air. That would be something...

 

[Zieg]

MST JETBOOTS - Divernet

YouTube - Jetboots Underwater Scuba Scooter

 

[Kiwi303]

well if you want spaghetti boots, I'll patent my idea for broom fins stiff rubber witches broom lookalikes, so new divers can sweep the reef clean as they swim, do your part and look after the underwater sights by keeping them sparkling and clean behind you

How many would buy that?

 

[diver_doug]

I'll throw this out one more time. How many paddle steamers do you see out there today? None but for casinos and Disney World. Who'd of thought that a little propeller spinning under the hull of a boat would be more efficient than big stiff boards pushing water.

How many paddle steamers do I see out there? Not many. How many paddle steamers do I see out there with a big-ass split down the middle of each paddle? None.

Now that I think about it, I believe propellers are antiquated technology. I think (for maximum propulsion and efficiency) boats should have their propellers replaced with a split fin that is attached to a paint shaker.