Do split fins improve air consumption?

[stokes]

I use Mares Avanti-3 fins and am quite satisfied with them. Recently I tried TUSA split fins on one dive and seemed to be consuming less air. Though this could be merely a perception formed by previous notions that split fins improve air consumption... so, do split fins show an improvement in air consumption?

 

[miked]

Hi Stokes,

There are numerous threads relating to "split fins" floating (no pun intended) around the board. Try a search, and you'll see that there is a wide range of opinions on split fins-ranging from "the best thing ever for divers" to "pure unadulterated hype/BS-worthless", and everything in between.
Some of the "lowered air consumption" advocates seem to feel that the reduced air usage is a result of the lower effort needed to propel yourself when using split fins. Others disagree. I think the results, like these opinions, will vary with individual experience.
My experience: when I got my split fins (Scuba Pro black), I did not notice a significant reduction in my air consumption, compared to my USD Blades. What I did notice was a significant decrease in leg fatigue the day after a 4-dive day. That is very important to me on a trip consisting of a series of 4-dive days.
If you do have a significant reduction in air consumption, get the fins!!
Good luck,
Mike

 

[TexasMike]

They did for me....but the biggest thing that helped my air consumption was to continue diving....slow down.....continue diving....pay attention to breathing pattern (long, slow and deep)....and continue diving.

 

[WreckWriter]

Nah, they just decrease swimming speed

Tom

 

[WreckWriter]

that was odd... I went to edit for a mispelled word and got another post. Now that I'm editing it will I get another?

 

[MikeFerrara]

ok. Nobody on this board has ever heard (read) me say a single good thing about split fins. In fact, my original instructor who sold me my force fins and later my split fins should have all that money taken out of his hide!

Anyhow, I currently have a student who baught his mask and fins while visiting freinds out of town. They disagreed with me and he chose to take their advice and get split fins. While teaching the class what fins and feet are really fore I noticed that this young athletic man appeared to have a serioous affliction when he trie to frog kick. So...last night I took some split fins with me to the pool. My plan was to use then for a while and find out first hand what I could do to help him. I did dive split fins for several months but that was before I learned how to kick.

I tried a frog kick first, no speed no power. I thought I would try them against a flow. I was unable to make headway against the water jet at the edge of the pool. I tried a modified frog thinking that maybe they would be better with a softer kick. The modified frog yielded more of a shaking back and forth than foreward motion. I tried a reverse frog. I swim backwards alot. in fact, my wife and I go through buoyancy control courses backwards. Again more of a shake than a move. So...then I decided to try using what I have been told is the proper kick with split fins (a flutter with a short stroke). After a few kick cycles I was clipping along ok. Indeed, it was easy on my legs but so is a good modified frog using mostly the ankles (even if you have 2 X 4's on your feet). Of course, I rarely use a flutter (other than a very modified one) because it is so hard on the environment, is so much work and doesn't give the precise control of other kicks. I went to stop and found that brakes don't come with these things.

Conclusion: I will no longer permit students to use them in class. A student who is using split fins has no chance of learning descent finning technique. I have heard people say that they can use all these kicks with split fins well...maybe... but I don't believe they go anywhere when they use them. Use less air? No. I was breathing hard for worry that someone would see.

 

[divernva]

Yup. They don't work well for any of the modified kicks... least of all the backwards kick and therefore heli turns.

If you're not concerned or even know why you'd use any of those kicks. Then split fins are great for flutter kicking. And most likely would reduce air consumption. But so does not using your arms, proper trim and bouyancy.

If you really want to reduce air consumption and increase bottom time, buy a scooter.