DIR Fin Compliance

[PfcAJ]

Ugh. A "passable" back kick? What GUE class have you taken?

Once again, back kick isn't just for backing out of tight spaces. Stop yourself when doing an OOG drill, hold your position while in the water column, adjust yourself while you help your buddy with something, the list goes on!

Something tells me that you can't do any of that and your diving "transmission" is stuck in drive while you do even the simplest tasks. Passable? I'm sure you meant "I pass right over that skill".

 

[rjack321]

Ugh. A "passable" back kick? What GUE class have you taken?

Once again, back kick isn't just for backing out of tight spaces. Stop yourself when doing an OOG drill, hold your position while in the water column, adjust yourself while you help your buddy with something, the list goes on!

Something tells me that you can't do any of that and your diving "transmission" is stuck in drive while you do even the simplest tasks. Passable? I'm sure you meant "I pass right over that skill".

And don't forget to avoid crashing into your buddy when you swim together on an s-drill! I wonder who defined passable for b1gcountry?

 

[PfcAJ]

Apparently the same person that showed him the GUE standards.

 

[CompuDude]

For Frog Kicking, I can hands down get more speed with less effort with my splits than I can with turtles. The blades are just too short for me to get any power. I go faster and kick less with my splits.

I call BS. With the frog kick above all other kicks, it's a simple question of how big the scoop is that's doing the scooping in the water. Splits do not present the same surface area, because as soon as they, well, split, the water is vectoring in the wrong direction.

I like splits. I think they have their place. But that place is NOT in DIR diving. And while I'm actually willing to believe you can do all the required kicks in splits, I am NOT willing to believe that they can be done as efficiently as they can in Jet fins.

 

[nadwidny]

Split fins very well may be inferior to a set of HBFs*, but based on the knee-jerk reaction most advanced and wanna-ba advanced divers have to them, its more than just the performance aspect of the fins that some divers are averse to. I think a lot of people are scared of showing up on a "serious" dive boat and being taken for a stroke because they are wearing split fins. I also think there are a lot of people who rag on split fins who have never tried them. Its ironic that they poke fun at split fins as being a gimmic, when they in fact are relying on something other than firsthand experience themselves. I think if there wasn't such a stigma against split fins in the DIB** community, then more people would actually use them.

I tried splits. They sucked. No stigma, they just sucked.

BTW, to the OP, there is nothing against split fins in any of the DIR literature that I've seen. I also know of no restrictions against split fins for any of the GUE classes, or any GUE instructors I've talked with. The main requirement is that you are able to perform the basic five finning techniques capably. I would say the best test for your split fins is to take them to the pool, or OW and practice flutter kicks, frog kicks, modified flutter, modified frog kicks, reverse kicking, and helicopter turns and see how they perform for you. It is the performance that matters, not the look.

Let's see how you did...

"nothing against split fins in any of the DIR literature that I've seen"... WRONG!

"I also know of no restrictions against split fins for any of the GUE classes"...WRONG!

"or any GUE instructors I've talked with"... WRONG (it's obvious that you never talked to a GUE instructor) As a matter of fact I've seen Bil Phillips from Tulum (who is not DIR but is a very experienced cave instructor) thumb a class when his student pulled out splits. Why? Because split fins suck.

" It is the performance that matters, not the look."...Well you got something right. Splits have the look that makes the newbies drool but they sure don't have the performance.

So you got 1 out of 4 right. We will take that into account next time you offer up your opinion on a subject.

 

[b1gcountry]

If there is no stigma against split fins in the DIR community, then why is everyone trying to cruicify me for bring up the topic?

Yet those who routinely swim double 104s, drysuits, and 2-3 deco bottles choose to use Jet Fins and Turtles? Your experience differs from the majority of the technical diving community. Are all of us just wrong?

First off, I've never tried swimming in Split Fins with double 104s, a drysuit, and 2-3 stage bottles, although in the latest Wreck Diving Magazine, there is a picture of a guy doing that exact thing (except I think he only had one stage) with a pair of Tusa Xpert Zooms (the fin I use.) The "majority" of the technical diving community can't determine whether I can use split fins efficiently, which I can and is all I was ever trying to say in the first place.

Those people probably are able to figure out the inherent flaw in the design without *needing* to try them.

As for the "inherent flaw" in their design, one major inefficiency in airplanes is the air that slips off the tips of the wings which still adds drag, but does not give lift because it flows over the edge without speeding up and producing lift (Bernoulli). The same can be applied to underwater propulsion. Any water that spills off the side of the fin is wasted energy. Split fins don't spill any water off the sides, and the water is directed backwards, so as for "inherent flaw" you're either going to have to elaborate on that, or retract it.

I'll believe your backkick when I see it

Once again, back kick isn't just for backing out of tight spaces. Stop yourself when doing an OOG drill, hold your position while in the water column, adjust yourself while you help your buddy with something, the list goes on!

Something tells me that you can't do any of that and your diving "transmission" is stuck in drive while you do even the simplest tasks. Passable? I'm sure you meant "I pass right over that skill".

Alright, stop by on the Milwaukee on August 12th, I'm organizing a charter there. I'll even buy you a beer afterwards. As to "Passable", those are exactly the things I was talking about. The only thing I wouln't feel comfortable is backfinning for distances, as I have said before, it is not as efficient. I'm also not great at backfinning without kicking up silt when I'm close to the bottom, but I'm working at it.

I call BS. With the frog kick above all other kicks, it's a simple question of how big the scoop is that's doing the scooping in the water. Splits do not present the same surface area, because as soon as they, well, split, the water is vectoring in the wrong direction.

I like splits. I think they have their place. But that place is NOT in DIR diving. And while I'm actually willing to believe you can do all the required kicks in splits, I am NOT willing to believe that they can be done as efficiently as they can in Jet fins.

The surface area isn't the only issue. Like I said earlier, if the water is flowing over the edges, it does no good. I was surprised as well when I finally figured out how to frog kick in splits how efficient they were. The frog kick is my main kick when swimming, and I've been using it for the past two years. It's much more comfortable that flutter kicking, although I still go to the flutter when there is a tough current I'm fighting against.

As to the GUE standards thing, that comes from some previous posts on this board where someone was talking about their DIR-F class and Split Fins were brought up. One of the board members, who claimed to be a GUE instructor said he didn't mind what fins students used as long as they could get the skills down...which was my advice to the OP the whole time.

I won't be convincing anyone of the repliers, I'm sure, but maybe there are a few lurkers who get my point. Anyway, I'm done here.

Peace out,
T

 

[Soggy]

If there is no stigma against split fins in the DIR community, then why is everyone trying to cruicify me for bring up the topic?

The only stigma is that they are inadequate and not suitable for DIR diving for countless reasons that have been brought up countless times and have been experienced by countless individuals, including myself.

First off, I've never tried swimming in Split Fins with double 104s, a drysuit, and 2-3 stage bottles, although in the latest Wreck Diving Magazine, there is a picture of a guy doing that exact thing (except I think he only had one stage) with a pair of Tusa Xpert Zooms (the fin I use.)

There are often people with poor gear choices in Wreck Diving Magazine. That really doesn't support your position at all

As for the "inherent flaw" in their design, one major inefficiency in airplanes is the air that slips off the tips of the wings which still adds drag, but does not give lift because it flows over the edge without speeding up and producing lift (Bernoulli). The same can be applied to underwater propulsion. Any water that spills off the side of the fin is wasted energy. Split fins don't spill any water off the sides, and the water is directed backwards, so as for "inherent flaw" you're either going to have to elaborate on that, or retract it.

Yet, when push comes to shove, they don't get the job done. I don't really care to do a physics analysis of them. When they are on the feet, they don't work as well as a stiff paddle fin.

Alright, stop by on the Milwaukee on August 12th, I'm organizing a charter there. I'll even buy you a beer afterwards.

I'm diving off Cape Cod that weekend, sorry

As to the GUE standards thing, that comes from some previous posts on this board where someone was talking about their DIR-F class and Split Fins were brought up. One of the board members, who claimed to be a GUE instructor said he didn't mind what fins students used as long as they could get the skills down...which was my advice to the OP the whole time.

I bet that almost any GUE instructor would let you try to struggle through a DIRF with split fins for a little while until you caved in and got a set of paddles and realized the difference. The video doesn't lie. GUE has the non-split rule for a reason -- people just aren't able to do the necessary skills with split fins. It's as simple as that.

 

[Soggy]

Let's step back and analyze the pieces of various kicks to try and demonstrate why split fins don't work well.

The following descriptions of the kick are very rough....

Frog kick:

• The kick begins with your knees bent, feet flat, legs together.
• The fins are extended sideways, while flat, with the edge of the fin cutting through the water
• The ankles are turned in, and the feet are brought together while extending the legs. A really strong frog kick can have the bottom of the fins touching at the end of this step.
• feet are brought straight back and then ankles rotated out again to the starting position

A frog kick is 'doable' in a set of split fins, though there is a lot of efficiency lost especially in the part where you separate your legs and bring the fins out. The split fins, due to their inherent floppiness and extra edge catch the water on this motion and pull the split apart, wasting a bunch of energy. Then, on the kick portion where you extend the legs, the fins go in like 8 different directions. The bigger the kick, the more this happens. Again, video does not lie.

Back kick:
A back kick is like a frog kick, in reverse.

• First, you bring the feet together, ankles turned in with the knees bent
• The feet, together, are pushed backwards, using the tips of the fin to break the water so you don't move forward in this step
• The legs are then extended and the fins flared while you bring the legs back in. This is where you move backwards

On a back kick, the part where split fins fail miserably is the extension with the fins together. The tips of the fin flail in multiple directions and tend to cause forward thrust when you are trying to move backwards.

The helicopter turn is a frog kick with one leg and a back kick with the other, so the deficiencies of the split fins should be obvious from the above description.

 

[jivebaby]

"If there is no stigma against split fins in the DIR community, then why is everyone trying to cruicify me for bring up the topic?"

Who cares about stigma. One if the best divers I know, a tech instructor with 1000's of dives uses splits. Use what works. Take from DIR what works for you and forget the rest.

Mike

 

[Soggy]

Who cares about stigma. One if the best divers I know, a tech instructor with 1000's of dives uses splits. Use what works. Take from DIR what works for you and forget the rest.

How do you define a good diver? What are your criteria?