Using Split fins in Strong Current!

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SeaHound:
I am about to purchase a pair of Apollo Bio Extra Torque Fins but am discouraged by the rumour that splits dont work well in currents. Is it true? How is it possible for a fin to "not work well" in current if it is generating stronger propulsion ins still waters? Anyone care to shed light on this?
My opinion of split fins?

I've only used them once and that was during my equiment exchange for Divemaster. My buddy and I exchanged equiment before so that we would be switching into our regular gear rather than out of it. My buddy used split fins.

We did this in a pool with 0 current. I immedatly noticed 2 things:

1. I felt like I had no fins one (i.e. I might as well have had no fins on because I wasn't getting any "umpf" out of them.)
2. I felt like my feet were weightless.

I wound up pulling myself hand over hand to the other end of the pool to do the exchange and was never happier to get rid of a pair of fins in my life.

Disclaimer, I spent as most 2 minutes moving in split fins so they might take a little more getting used to, I was also overweighted by plan.
 
I find my split fins to be fine. I can keep up with anybody, even though I am much smaller and weaker. But they feel like noodles on my feet when I have to do a surface swim on my back. They don't seem to work real well up-side-downish.

Also, I get into our RIB with no problems with my split fins despite the fact I can't even do a single chin-up. Can't get into a canoe wearing only a bathing suit to save my life (really - I've actually had to do this, I needed a boost!) Must admit that I clip my rig to the dinghy and take it off before propelling myself aboard.... Getting in with no fins is impossible for me.... Tried that, too...
 
If you're in current, let's say not in blue water, it is usually less strong near whatever underwater topology you have, e.g. the bottom.

In this case, not requiring the full, powerful kicks needed for strong propulsion using paddle fins is a good thing, since you don't really want to be kicking the bottom.

-Simon
 
simonk999:
In this case, not requiring the full, powerful kicks needed for strong propulsion using paddle fins is a good thing, since you don't really want to be kicking the bottom.
OTOH, one disadvantage to splits that doesn't seem to be mentioned often is that the vortexes that come off the fins will travel a long distance and still have enough energy to stir up the bottom. I've seen divers with head up/feet down trim stir up the bottom from 15' above it when using splits.

Objective tests have repeatedly shown that they are the fastest, most efficient fins, but there are some drawbacks.
 
Charlie99, that's an interesting observation. Indeed the vortex generation is the design goal of the splits, vs the general "push some water" theory of operation of paddle fins. Maybe split users need to wear a sign visible to following divers:
"caution, wake turbulence" :wink:
 
Charlie99:
OTOH, one disadvantage to splits that doesn't seem to be mentioned often is that the vortexes that come off the fins will travel a long distance and still have enough energy to stir up the bottom. I've seen divers with head up/feet down trim stir up the bottom from 15' above it when using splits.

Objective tests have repeatedly shown that they are the fastest, most efficient fins, but there are some drawbacks.

Weird that you would say that, as I've found basically the opposite... The water coming off the fins goes more 'straight back' instead of down... so I guess if as you say, the divers are head up, feet down, they are kicking at the bottom, and since these fins have more thrust, they will push more water, but if in a good diving position - horizontal, I find a lot less bottom disturbance.

Here's a link to a video on apollo's site that shows the effect of swimming right along a sandy bottom with splits: http://apollosportsusa.com/videos/apollo4.ram
 
Uncle Pug:
Also... when it comes to propelling yourself out of the water and onto a RIB split fins are no match for the instant power of Jets/Turtles.

Having recently coverted to Bio splits, I would agree with Uncle Pug on the "instant" thrust... a paddle will beat it in that category.
However, for the average rec. diver, I wonder which is more important: having the ability to thrust yourself forward a bunch with one big kick, or overall efficiency and comfort over the entire dive.

I had ankle surgery some time back and the constant torque of the paddles would make that ankle ache pretty bad after a dive or three. With the bio's, no pain at all, and performance was fine for me. As others have mentioned, you do have to modify your kick to a shorter stroke... see the link to apollo in Larry's message below. There's no way you'll master this in one trip down the length of the pool if you've used paddles for years, old habits were hard for me to break. A full hard kick will get you nowhere fast with the bio's... kinda like spinning your tires in a car. The proper stroke makes all the difference with these.

There certainly are conditions/divers who would need the paddle, but for me, I'm just an average diver chasing lobsters and an occasional mermaid . The bio splits were a welcome change for me.
Jeff
 
scubatoys:
Here's a link to a video on apollo's site that shows the effect of swimming right along a sandy bottom with splits: http://apollosportsusa.com/videos/apollo4.ram
LOL ... take a close look at ankle and foot positioning of the side shots towards the end of the film. Obvious rigging of the test in favor of their product! :banana: Maybe they figured that, with all the bogus criticism of splits floating around, that a little bogus hit on paddle fins was OK ???


I've seen lots of split fins used near the bottom without stirring anything up. OTOH, the first time I saw an out-of-trim diver stirring up the bottom from 15 or 20' up it really caught my attention. At first it was hard to even figure out who was causing these puffs of silt to appear. Kind of reminded me of this toy I used to have that you shoot vortexes or smoke rings all the way across the room.
 
Uncle Pug:
When Mike Ferrara closed his dive shop he had a fair of unsold biofins left and he sent them to me to try.

I found that I could back up and do helicopter turns with them... but with no where the efficiency that I can with Turtles. Duct taping the Biofins helped a little but not enough to bother.

Also... when it comes to propelling yourself out of the water and onto a RIB split fins are no match for the instant power of Jets/Turtles.

about the RIB... but I wonder if it may be true in other situations... i.e. diver tow. The "tests" of these fins should be a lot more comprehensive. Anyhow... I change my mind about what kinds of equipment I like every year. My store loves me.
 

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