Bob Evans and Susanne Chess

An Interview with the 'Finatics' at Force Fin

By Chris Kostman

A version of this was originally published in aquaCORPS, February/March 1996.

Much maligned and misunderstood, Force Fins and their iconoclastic creators, Bob Evans and Susanne Chess, have been leading a quiet revolution within the dive industry. Long shunned by the dive industry power brokers, the pair are the propagators of the polyurethane fins shaped to resemble the tail end of tuna or a dolphin. Inspired by the natural locomotion of aquatic creatures and with barnacle-like tenacity, the pair have led Force Fin from the sketch pad to major market player over twenty-four tumultuous years. Along the way, they've experienced broad acceptance from the swimming community, yet almost total disdain from the mainstream of the dive industry. They've weathered unscrupulous efforts to undermine their stature here in the U.S., yet been embraced by the foreign dive press and have even been put to use by the Russian Navy. Ignored by the American dive press, they've been overwhelmed by the mainstream news media and general public here in the States.

But whether hailed as visionaries or ridiculed by members of their own industry, Evans and Chess have sailed their ship well, generating droves of loyal followers in swimming, fishing, and now, finally, in diving. "The industry is finally ready to accept us, to look beyond what our fins look like," says Evans.

Here, in an exclusive interview conducted at their offices in Santa Barbara, CA, is an inside look at a great American success story:

Chris Kostman: The name seems like a logical place to start. What does 'Force Fin' mean?

Bob Evans: "We call them Force Fins because, unlike any other fin, they generate so much lift that they actually force themselves onto your feet. You don't even need a strap to keep them on. When it comes to fins, the question you have to ask yourself is: 'Are you working for the fin, or is the fin working for you?' Just do a simple test to see how your fins are working: take the strap off and see if your fins stay on. If your fins fall off, then they're working on drag and they're doing nothing for you. If the fin stays on without a strap, then the fin is working on lift and it's working for you. It's like a pilot expecting to look outside the plane and see the wings flapping. You don't have to feel your fins for them to be working!"

CK: How did this all start?

BE: "I was an underwater photographer. I just had the basic idea for the fins based on years of watching fish and big pelagics moving through water. I wasn't really a designer, but I had learned molding and other skills from my dad, who's a sculptor. So I kept designing and refining my fin idea, and every year I'd get the new dive catalogues and see that the dive manufacturers just had the same old fins every year. It took me twelve years, having started in 1971, and I had this real insecurity being this little person up against these big companies. And then I'd make another model of my fin idea, make it better and better, and then I'd look at the catalogues and see the manufacturers still had the same old fins. So I kept getting spurred on and after a few years I realized 'these guys are never going to get it!' The other manufacturers just kept doing the same old stuff and packaging it to look different. It was the same old thing: a board with a foot pocket on it."

So in 1971 I had started designing the fins, mainly looking at fish and things that moved through water for my inspiration. But after nine years, in 1980, I didn't know what to do with my life. So I sat down with Laddie (Handelman), the founder of Oceaneering, and he spent five hours of his time with me and made this little drawing. I was thirty and at a turning point in my life and this drawing showed where the most potential was for me. I could have stayed in underwater photography and all the other projects like making camera housings for deep water video, but the fin looked like it had the most potential. So in 1980 I committed to the fins full-time. After that, I stomped and I worked ten hours every single day for two and a half years on the fin, completing prototype, prototype, prototype. It was so insane that when I was done with the project, I had not done my laundry in two and a half years. I just kept buying new swim trunks and t-shirts. So I went to the laundromat and filled up every single washing machine. It took two cars to carry all the t-shirts and trunks. You put your mind to something and you do it. Everything else is secondary."

CK: The fins are obviously totally different from anyone else's. How do you explain all the intricacies of the design?

BE: "My first concept was that a fin should be curved on the backside, because you have to drag the fin back up through the water on the upstroke. I mean, divers still think that they're getting power as they bring the fin up through the water. But there is no physical way that's going to be taking place with a flat fin. The hamstrings just can't work like the quads, plus your ankle bends. The ankle can't hold out against the water; it bends like a hinge or a trap door. Another thing I recognized was that the ribs on the side of other fins didn't allow the water in front of you to get into the working area of the fin. The ribs were there to stiffen up the fin, but if you want to be able to maneuver, then those ribs are like a brick wall. So the curved back side of my fins allows you to easily bring the fin back up through the water so you can kick back down. It's like picking up a skimboard off the beach. If you punch it full of holes, you can pick it back up easier. And that's why a Jet Fin has a bunch of holes in it, so you can pick it back up more easily. The problem is that the water strains back and forth in both directions, which increases the drag. But a Force Fin is like a cup. It carries the water one way, then comes back quickly to do that over again."

Now people say 'a flexible fin doesn't have any power.' and that's true IF you have a flat, linear design that's flexible. But our fin is changing continually throughout the whole cycle. I saw a slow motion video of a harbor seal, and our fin is just like that. It has power in one direction and then collapses while throwing water behind in the other direction so that it can get back to where you kick against it without strain. And you don't lose any directional flow of the water when it does this."

And those upcurved wingtips? They're a perfect foil. They provide lift. One of the America's Cup teams actually modeled their keel after our fins, based on the information derived from studying Force Fins in Boeing's wind tunnel. You see, unlike other fins, if you aren't kicking at all and are using your arms to drag you through the water, the fins will lift your feet up and hold them up. Other fins are like an anchor and just drag your feet down."

CK: What's it like bucking all the trends like that?

BE: "Well, once the dive industry lets it register that my design is the only way to go, then they'll ALL go this way. But they're going to let me do all the work before they rip me off. Ten years ago, Dick Bonin, the President of Scubapro, said 'I understand what you've done here, but I think it's going to take ten years for this industry to even begin to understand what you've done.'"

CK: That prediction seems to be bearing out. How do you explain that?

Susanne Chess: "It's an example of how you have to have the perseverance and be like a barnacle and just never let go. You just have to push it through."

CK: Because of the design of your fin, divers have to kick differently than with other dive fins. Have you had to reeducate the diving public?

BE: "I learned more about the physiology for moving through water from fish and swimming coaches than from diving. In diving, it was just 'put on some fins and swim with them.' Diving is still teaching a kick style that went out twenty years ago in swimming, and that's the real wide, drag-dominated kick."

The instructional agencies should have told the manufacturers years ago that this is a ridiculous kick style. Why doesn't someone make a fin that allows for a natural kick cycle? Just recently, Underwater USA was saying "You learned how to swim in a swimming class, but now you have to forget that great technique you learned and learn how to kick the way a diver does.' So you take someone with good kicking style and then you make them kick with a kicking style that was scientifically proven to be wrong and inefficient over twenty years ago. In other words, divers are being taught to kick the wrong way."

CK: What do you mean, the 'wrong way?'

BE: "The leading swimming expert some twenty years ago was Doc Counsilman, at the University of Indiana. He did videotape studies of Mark Spitz and, up until that point, everyone believed and taught swimming based on a drag-dominated kick. This theory is that you use the drag of the water to push behind you. But when they studied Mark Spitz, they discovered he was using the flexibility of his muscles and a flapping motion with his arms, legs, and feet to get the water moving behind him using more lift forces. So after realizing this, Bob Counsilman published an article explaining this and basically said 'I retract everything I ever said before.' That dramatically changed swimming forever."

CK: So this totally changed the way swimming was coached, but how about diving?

SC: "Diving didn't follow. You see, when you're using lift forces, you want to use more of a flapping motion to kick, which means a higher frequency with less load. But the diving fins at that time started becoming stiffer and longer. If you use a flapping motion with a big, long, or heavy fin, you'll get oxygen depleted. But if you use a fin that's designed for a flapping motion, a fin that's shorter and more flexible, you won't get oxygen depleted. So it was the equipment that kept the instruction from transitioning. The diving had gotten on a track that said 'This is the way we've written our books and our instruction, so this is what we're going to say for the marketing. This is the way it is.' So as an industry, they weren't willing to change the track."

It wasn't until Bob came along with the Force Fin and started saying 'No, no, no, no!' and bucking the trend that there's even been a slow transition over the last few years. Now fins are actually starting to change. You'll see fins are beginning to have more flexibility and the manufacturers are starting to change how fins are marketed. Finally, ribs and vents are slowly starting to disappear and fins are becoming more flexible."

CK: Explain the interplay between equipment and instruction.

SC: "The instruction gets developed based on the equipment that exists at the time. When the equipment changes, instruction is very slow in changing. Look at tech diving: With nitrox right now, for example, the instruction is set up for sport divers using normal compressed air. So now the educational programs have to be developed in order for nitrox to be able to be accepted. It's the same with back-mounted BC's, where the instruction was based on a certain type of BC. Until the instruction agencies changed, everyone said you'd float on your stomach and drown from back-mounted BC's. Now that the industry has changed and caught up with that, those BC's are used. Likewise for fins, because they had long, stiff fins, they taught a drag-dominated kick, not because the kick was better but because it happened to work within the instructional agencies for use with that type of fins. They've gotten themselves locked in a paradigm with their instruction choice. So they can't use a better fin like ours, unless they open their mind and break down their little paradigm and learn how to teach people to use a natural kick stroke for swimming that they don't even have to teach!"

CK: As the saying goes, 'the proof is in the pudding.' Where's the proof?

BE: "Take our sales from 1984 to 1987 in The Sharper Image, for example. They sold nearly one million dollars worth of our fins and they have a money-back guarantee. Well, they had less than a 1% return rate, most of which was based on sizing problems. And I have eight different sizes of fins, more than anyone else. My fins are proportional to the foot size. Small feet have small blades; big feet get bigger blades. I was thinking like an end-user when I designed them that way. I didn't know what a nightmare it would be in terms of the tooling costs. That's why most other manufacturers use the same blade regardless of the foot pocket size. It keeps their costs down."

But the main point about The Sharper Image is that if the fins are so lousy, then they would have had a major return rate and our fins wouldn't have stayed in their catalogue. But since only less than 1% of them came back, what that meant to me was that if I could get my fins into somebody's hands, they like them and the fins work. And Performance Diver has had only five pair come back in the more than four years since they started selling them. So here again, the key is if someone is allowed to make a conscious choice on their own and they're not told what to do, then that person will walk out the door with our fin. It's been proven by The Sharper Image, by Performance Diver, and by the shops that sell our fins. By the way, selling through Performance Diver was like the Berlin Wall coming down for our business, because for the first time I was out of the grip of the old dive store relationship. What was wrong with the dive industry saying it was a lousy fin? It's like a horse with blinders on thinking and seeing just one particular way."

CK: You don't seem too happy with the way the dive industry works. Why?

BE: "Well, when we'd call the dive stores about selling our fins, traditionally they have said stuff like 'I'm not interested in Force Fins. I'm a Scubapro store, or Dacor store, or a U.S. Divers store. I only carry products from this company or that company.' So the stores have been part of buying programs and we feel that these programs have really worked to the detriment of the dive industry because the shops can't have diversity in the things they sell. Companies that sell one type of product, like us, can't get sold in those stores."

Fortunately, the dive industry is changing and there are many stores that sell our fins now. And one thing we find about the stores that sell us is that they let the customers choose the fins that feel the best. And those stores sell about 70 to 80 percent Force Fins."

CK: You use different materials in your fins. What's that about?

BE: "Most fins in this industry are made of ethylvinylacetate (EVA), which is the cheapest plastic made. It costs about thirty cents per pound as raw material. My fins are made of polyurethane and they cost up to six dollars for the raw material. Everyone says plastic is great, but plastic is cheap, definitely not great, and only leads to higher margins for the manufacturer. For example, the plastic can't take heat, so plastic fins melt in your car or on the deck of your boat, they get brittle in cold water, and they lose their shape, which is why they come with a little shoe insert in them at the store. And once you start using them, they begin to collapse and they don't last."

The point is: my material's gold and the other fins' material is lead. It's a bunch of crap that EVA plastic is the way to go. If you want to make a fin that's worth anything, use anything but EVA, with polyurethane being the best choice."

CK: Finally you seem to be getting some good press in the dive industry. What has taken so long?

BE: "Press-wise, we have been featured for years outside of the dive industry, in Sports Illustrated, Outside, U.S. News and World Report, the New York Times, even Playboy and Penthouse. So the ton of press we were receiving everywhere but in the dive industry generated hundreds of thousands of users. This press and word of mouth that has been generated is bigger than the dive industry can contain."

SC: "We were becoming successful without the dive magazines, without the support of the instructional agencies, without the support of the dive stores. And never in the history of this industry had anybody made it without those three support systems in place with them. So we started becoming successful mostly through divers recommending our fins to other divers, which eventually forced some support from the dive magazines."

Actually, it was Ken Loyst at Discover Diving two years ago who finally took an honest look at our fins. And once he took that honest look, he was willing, just like Doc Counsilman, to say 'hey, I had this one perception, but when I took the time to actually understand this product, I realized I was wrong and I am willing to publish what it is the true results are.' And their conclusions were that Force Fins are half the size of other fins and the divers use half the energy to travel the same distance and carry the same load with our fins.'"

CK: Things seem to have finally come together for you. Where are you at today, and what's next?

BE: "Lots! We've sold over 100,000 pairs of fins to date and our overall sales are at a level fifteen times what they were in 1988. We're also moving into a new 3,600 square foot location. Product-wise, this year we introduced the Extra Force Fin, with patented variable thrust winglets attached. Also, we're selling these winglets, called Force Wings, as an aftermarket attachment for any fin so that anybody can 'add some force to their fins.'"

Bev Morgan of Kirby-Morgan and DSI once told me something: 'if you're going to do one thing, do it well.' That's why we have stayed in this one particular field. We will always be at the leading edge of fin design. It's what we live for."

For the rest of the Force Fin story, click here.

To visit the Force Fins website, click here.