pics above: B.Porotov and N.Turukalo in the Nuke's plant apartment building basement pool back in 1970 - Boris Porotov talks at a dive show in 2017:

It was only in 1968, after the European Underwater Sports Championship was held here in the USSR, in Alushta—that was actually the final year they still had the all-around multi-event competition—that I came to the conclusion we needed to take the monofin seriously.

And so, at that European Championship in 1968, a young kid from Novosibirsk showed up swimming with fins extended using glass-reinforced epoxy laminate, you know, FR4-style, for printed circuit boards. People had modified fins before, of course—handymen cutting and tinkering. They used to take steel plates and glue stuff; it was quite the circus with those fins. But when the FR4 laminate fin appeared—and I should add that at the 1968 European Championships, they introduced some extra pool events—this kid Kovalevsky, the one I’m talking about, swam very decently in those fins. And I started... well, already in many cities, people were starting to make fins with this plastic stuff, using FR4.

So, in 1968, I started building a monofin like this. What was this fin? (shows a photo) Here is our first monofin. It was built using the foot pockets of "Dolphin" fins from a Moscow factory, and the blade was made of titanium and rubber. We found a specific, highly resilient titanium alloy. We ground it down—it was 80 centimeters long—from two millimeters thick all the way down to 0.5 millimeters. We managed to do that to create, well, the right conditions for the tip of the fin to work efficiently. It was covered with a rubber tech-sheet: one side glossy, the other matte. This first monofin made its appearance at the USSR Speed Underwater Sports Championship in Kiev, back in 1969.

And that woman in the photo is Nadezhda Turukalo. She holds an Honored Master of Sports of the USSR title. When she first brought this fin to the pool, it caused a quiet a stir. She dives 25 meters. We had a great sprinter in Moscow, Valya Kuznetsova. She had won the previous championship just before that, diving a 11.3 seconds. Nadezhda dives—10.4 seconds. Over such a short distance, that kind of time difference is massive, obviously. And the very next day, we swam the 100-meter underwater event as well. Well, Turukalo wins two gold medals.

Then the results started coming in. We did a ton of experiments with this fin. We realized you could swim 400 meters in it, and eventually even longer distances, and we started developing other special swimming styles.

Now, at the 1970 USSR Peoples' Spartakiad in Minsk, she won yet another event—surface swimming with a monofin, where the body moves in a dolphin motion and the arms do a crawl stroke. It looked really graceful, and she won that event too, setting records along the way. All in all, she won four gold medals back then in Minsk.

As we refined things further, we came to the conclusion that swimming with arm strokes is actually worse than just swimming with your arms stretched straight out overhead.

What was the monofin even created for in the first place? Our task was to push underwater speeds as high as possible. And with the help of the monofin, we achieved just that.

Later, we moved on to... (shows photos) Here it is working underwater. And this is the first pool, built in the basement of a residential building—25 meters long, two lanes—where we ran all these experiments. Here is that first monofin from 1972, now made entirely of FR4. We kept changing the shapes, cutting them in different ways, making slots, and trimming-peeling away excess fiberglass layers.

Then, this... this is the fin Nadezhda Turukalo used to win the title of Absolute World Champion in Yugoslavia in 1973. She was the very first person in the world to swim underwater orienteering using a monofin.

Interestingly, when the monofin first appeared in 1969, for almost a whole year nobody even tried making one or swimming in it. It wasn't until the 1970 USSR Peoples' Spartakiad that another girl, Agafonova from Rostov, showed up and also started experimenting with it.

Then in 1971, at the national cup in Tashkent, these monofins appeared en masse—they started making them in Novosibirsk and Tomsk. And that was a whole revolution in underwater sports that began.

Still, adoption went gradually.

Since Turukalo was the first to swim underwater orienteering with this monofin, but nobody else was doing it yet, we kept pushing the thing: "Folks, you've got to start doing this." But it wasn't until 1980 that men and women finally started swimming underwater orienteering with monofins on a mass scale.

Now, if we talk about other sports—freediving, for example. Btw, we also had marathon swimming, where everyone swam 10 kilometers in monofins. But as for freediving, they only started wearing monofins about 10 years ago, mid 2000s. Natasha Molchanova—Alexey’s mom, who just spoke right before this presentation—she used to bug me with her students, asking me to give lectures on how to do it, how to kick. And if any of you find this stuff interesting now, if you have any questions about it, I’ll be happy to answer them.

Back then, though, what was the main problem? The problem was that materials for making a monofin were scarce. We got our hands on Soviet equivalent of FR4 with the greatest of difficulty. I remember making a special trip to Khotkovo—it's a town near Moscow—because there was a factory there that made that circuit boards laminate. But it turned out not to be what we needed: it had 12 layers and was way too coarse-grained. The fins broke often, completely useless.

Later on, we found a factory right here in Moscow called the "Isolit" plant. We got our laminate from them—with copper-foil on one side sheets. It has 21 layers. Exactly the material we needed. We peeled off the foil, and then we cut the fins with special knives, trying all sorts of approaches.

So, why can monofins reach such high speeds, and how did we get there? You understand that in freediving, you don't need a rigid monofin—there, especially, you want something soft, or just a little bit stiffer. But in speed underwater swimming, especially in 50-meter underwater sprints, the monofin has to be stiff. Only the very tip of the fin should work, snapping like a whip. A sharp, whip-like motion, and it does the magic, pushing water with great power and generating those high speeds.

To make something like that, it has to be crafted by someone who either swims themselves or is a coach. So when we made the fin, we try its elasticity by hand, by feel. You're working on it, you strip away a layer, but the elasticity still isn't right—that means this particular fin gets relegated to longer distances: swimming 400 meters or 800 meters. And you keep searching for that sweet spot to make one that works properly for a 50-meter sprint, because that's where the speeds start. You time 50 meters, then 100 meters underwater. Back in those days, one of our guys was already swimming 100 meters in 35.0 seconds. Can you imagine how high those speeds were? And today, those speeds are even higher. So once we figured out how it had to be done, we started outfitting all our teams with monofins.

When mass production took off, many countries tried to get in on it too. The East Germans were the first to try. But instead of peeling down layers from industrial circuit board laminate, they simply glued fiberglass cloth together, poured epoxy over it—thicker here, thinner there. No matter how hard they tried, they never produced a single good fin. Their fins were kind of standardized, but completely useless when you needed to match a fin to a specific distance. Then the Italians tried, then the French—factory-produced ones, I mean. And none of them got anywhere.

Later came a time when the Chinese started swimming really well in monofins. They even beat us in some events at World Championships. And that in part because our athletes and coaches supplied them with monofins. Tomsk worked a lot with China—they specially manufactured fins for them. I won't hide the fact that my own athletes in Alma-Ata also prepared batches of monofins for China. So that’s also why their performance grew and grew and grew.

And that’s basically how the monofin slowly spread across the entire world.

That’s pretty much everything I wanted to tell you. So, please, go ahead with your questions.

(inaudible question) (Haha... The thing is... Thank you. So...)

Oh, I forgot to mention, our very first monofin was made in Ust-Kamenogorsk, Eastern Kazakhstan. Why there? Well, after graduating, I worked there at a nuclear industry factory. It was a massive, powerful facility, and the technical resources were limitless. You could make literally anything there. Grinding an 80-centimeter titanium plate from 2 mm down to 0.5 mm—you wouldn’t normally find a machine for that, but they had one there. And we did it.

And that’s how everything started out there in Ust-Kamenogorsk. That’s also where we built our little "Dolphin" swimming pool.

(inaudible question) (What... ?)

Yes, the blade is 80 centimeters.

(inaudible question)

And we opened—we opened the pool on January 6, 1966. How did we manage to build it and why? Well, this "Dolphin" pool was built right underneath a residential apartment building. We went to the factory director, and he actually allowed us to take the building’s architectural blueprint and modify it. The factory was getting ready to build an apartment block, and the foundation pit was already dug. We altered the design, raised the building by one meter and eighty centimeters, and built a 25-meter by 4-meter pool with two lanes right into the basement. Turned out to be a fantastic pool!

Because there were no other swimming pools in the city, we immediately started serious work with children in both regular swimming and underwater swimming. In that tiny pool, I raised 20 Masters of Sports, 5 International Class Masters of Sports, and an Honored Master of Sports of the USSR—Nadezhda Prokopyevna Turukalo, who is basically one of the most prominent underwater sportswomen of the 20th century.

Any other questions?

(inaudible question)

Well, yes. And that first monofin is in the city museum. The one in the photo. Yes, that one. Yes, the rubberized fin is right there in the city museum. One can see it there.

Now, well, a few words from the President of the Underwater Activities Confederation of Russia, Valentin Grigoryevich Stashevsky.

= (Valentin Stashevsky speaking)

As this titan of underwater sports, Boris Glebovich Porotov, was telling you his story, I kept wanting to chime in. He kept saying "diving, diving"—you guys might hear "diving" and think of deep-sea freediving, but you need to know this was speed-diving in pool of course. Back then it was 40 meters for men and 25 meters for women, in length. Later on, our disciplines evolved, and today both men and women dive 50 meters in monofins.

Aside from honoring him as the inventor of the monofin and an Honored Coach, I wanted to add a little TV-show-style detail: Nadezhda Turukalo became his wife. And when the Soviet Union went bust, they moved and now live in Sevastopol. She works at a children's sports school, and he continues to develop his community—an underwater club.

A few words about the international side of our sport. The Confédération Mondiale des Activités Subaquatiques (CMAS) was founded in 1959 by Jacques-Yves Cousteau and his friends. The USSR Underwater Sports Federation was also created in 1959—we are of same age.

Turns out they had been holding spearfishing competitions since 1957, even before CMAS officially existed.

Then in 1965—Boris was just telling you about the time when the monofin was being created, from 1964 until the first World Championship in 1973—the USSR Underwater Sports Federation joined CMAS. And we brought proposals to the table: "Please do spearfish, yet we're not racing in that department. But let's also take up pure sporting underwater disciplines—what they call 'goals, points, and seconds' today." When it comes to recording records, it has to be done under equal conditions, thus in a swimming pool, just like track and field on a stadium. So we went and persuaded CMAS—I won't go into details, it wasn't easy, and I served as Executive Secretary of the USSR Underwater Sports Federation from 1964 to 1971—and we pushed our program through in CMAS. And CMAS began holding championships in our sports, well, in sports we suggested.

At first, as Boris Glebovich mentioned, it was an underwater multi-event competition—scores were calculated across a combination of exercises. Later, they split it into separate events: pool competitions and open water competitions. The first World Underwater Orienteering Championship was held in 1973 in Yugoslavia. That’s where Nadezhda showed all her capabilities and earned the title of World Champion. Along with our other athletes, too.

And you won't believe this—I was looking at something online the other days... wait, everything is online now... and a Greek federation was posting a lot of materials about how fin swimming is practiced in pools in Greece. And I'm looking at the video—it's the 1972 European Championship in Moscow, at the Olympics’ pool. There were 20 gold medals up for grabs at that European Championship. Soviet athletes won all 20 gold medals. That’s how it was back then.

Now, when Boris Glebovich mentioned the Chinese earlier, he said they were supplied with fins—and not just fins. Back in the lean 1990s years, our poor coaches from Siberia, from Novosibirsk and Tomsk, went to China just to earn a living, and they taught the Chinese how to do fin swimming and used the best gear they had: the monofin. Yeah. It was in such a way, in the past.

Today, KPDR—the Confederation of Underwater Activities of Russia, which I represent—focuses solely on training and issuing international certifications. As CMAS members, we sit on the technical committee and the scientific committee. We involve underwater instructors and coaches, and assist scientists in ocean exploration—assisting in the broadest sense of the word. Meanwhile, the Underwater Sports Federation of Russia, FPSR, is a member of the CMAS sports committee and handles actual competition participation.

Thanks for the mic.

Ah, if I have one quick minute—one more thing: for a long time, traditional style swimmers didn't accept us. There was a division in our country between technical sports and Olympic sports. Our swimming and underwater sports were classified as technical sports. Which is fine. Cyclists turn wheels, right?—that’s a technical sport, and for us, it’s fins. Traditional swimmers didn't recognize us. I don't remember the exact year, but eventually, fin swimmers surpassed the world records of traditional style swimmers, and they finally quieted down. Was it 1974? Yes.

= Boris Glebovich Porotov resumes speaking

Well, if anyone has any questions, maybe.

I can talk with you more on this topic.

Yes, go ahead, I'm listening.

Question: Did you try to run any theoretical or hydrodynamic calculations?

BP: On the fin's characteristics?

Q: Yes, yes, yes. Or was it purely by trial and error, guesstimation, like you described?

Fin-making is still guesstimation, to this day. The fins are made of carbon fiber and everything else. Still you cannot just go and ask: "Build me a monofin for a 50-meter speed dive." Not a single factory in the world can do that. Because it can only be done by hand, constantly stripping away layers and feeling by hand how that fin is going to perform. You see, that can only be done by someone who has actually swum in one, right? Look at what Alex (Molchanov) just told us: he has 10 pairs of fins, and all of them are different. One fin he might use for a specific depth or tempo, and another he can't. So factories manufacture fins, people buy them, and then they try to figure out: "What fits me? Will this fin work for me or not?" An industrial maker mentions things like stiffness number one, stiffness number two. But I still don't know of any technology that can actually measure these fins. Purely technically speaking, how do you measure what kind of rebound a fin will have? Sure, you can lay it down, hang something from it, and watch how the blade bends. But what will its rebound be in the water? That’s the problem. Plus, people are all different. One person has longer legs, another has shorter legs. But what makes the monofin so powerful? It forces every muscle in the human body to work—especially the large ones in the butt, back, and thighs—all working together. And that means a person actually spends less energy per cycle. That movement is far more efficient than trying to kick back and forth alternating legs to build up whatever speeds we can.

When we do all this, we practically cannot measure our actual effort. There is no equipment yet, no ways to measure how actually this specific monofin will perform. But when a swimmer tests it out, tunes the monofin to themselves by feel, they know exactly what kind of kick they can deliver in it and set a world record. For instance, in a 50-meter dive, or swimming a hundred.

I had that guy athlete, Oleg Ananiev. We brought him from Alma-Ata to Sevastopol when we moved. He swam and set a world record that stood for a long time: 35 seconds for 100 meters. Well, to achieve that record, we went through about a dozen monofins before finally finding the exact variant that was fastest for that specific distance. See what I mean? That’s why a factory... I don't know how a factory could make fins by pre-calculating that they'll be record-breakers for a specific discipline.

In freediving, though, high speed isn't what's needed. The main thing there is spending as little effort as possible to grab your greatest depth.

I mean energy conservation has to come from working your pelvis well, engaging, letting the fin propel you well. But how to measure all that for calculation—I have no idea.

That's it, thank you. No more questions?

Thank you.

Yes, I'm listening.

What's that? (inaudible, voice from the audience)

Thank you, Boris Glebovich Porotov.

(pics & credits: Boris Porotov; tutrin; Советский спорт №3-1971 Киножурнал №12410; Soviet monofins history 1930-2020, Jdanov, Titov, 2024, Tomsk univ. press, DOI: 10.17223/19988613/70/24 (Rus., to be translated); Porotov talk:  Rus original audio )

The History Of Monofins And Bifins (Design, Patenting And Making, 1930–2020) 

This paper describes the history of swimming fins from their earliest days to the present. It covers the first molded rubber fins, combined and composite fins that laid the foundation for high-speed designs, and sports fins built with fiberglass laminate as a new engineering solution. R&D of the "wing" fins as the prototype for further progress. Various models of monofins key to high swimming speed. Patent trend for different fin types across the top 10 countries in this field. Tracing this history was fascinating for the authors, since with other Soviet inventors they contributed to fin design. 

V.V. Zhdanov, V.B. Titov

Tomsk State University Bulletin. History. 2021. No. 70

Problems of the history of science and technology

UDC 797.2 (091)

DOI: 10.17223/19988613/70/24 ,<= full text in Rus

Keywords: fins; swimming; inventions; patents; fiberglass; monofins. 

(translaed for the Freediving Federation from the original paper freely accessible at  CyberLeninka)

Back in 1717, American Benjamin Franklin patented swim fins with wooden blades. For military use, Frenchman Luis Marie de Corlien designed a "water-propulsion device" in 1929 and patented it in 1933 (FR, pat. No. 767013(A), 1934)(fig.1)[1]. In 1940, American Owen R. Churchill improved Corlien's design (USA, pat. 2321009, 1943)[3]. Hundreds of fin designs have been patented since then. Below are the cumulative patenting trends for various fin models across the top 10 countries (fig.2)[2]. 

fig.1  fig.2 (see original paper link above)

However, only a handful of these designs was implemented in actual sports fins, and those are the ones we will review here. 

In 1943, Jacques-Yves Cousteau and Émile Gagnan invented the Scuba and gave humans the ability to swim and breathe underwater. This triggered a massive increase in underwater research and sports. By the early 1950s, countries like Italy, France, and the USA started mass-producing rubber bifins. 

Among the first major competitions of distance swimming and diving in fins was the 1st USSR Underwater Sports Championship held in Karabakh, Crimea, in 1958. Men quickly proved humans hit their highest speeds during short-distance fin diving. At the 2nd USSR Championship in Alushta (1959), M. Zaslavsky from Moscow won the 40 m underwater dive in 22.0 seconds using Bulgarian "Sadala Gigant" fins—which were literally the only pair of these fins in our entire country at the time. He won again in 1960 with a time of 21.8 seconds. 

The World Underwater Federation (CMAS) was created in 1959 with Jacques-Yves Cousteau as its first president, and today it unites national federations from about 100 countries. By the early 1960s, CMAS launched international competitions where athletes' primary goal was mostly highest speed. In 1959–1960, they started using molded-rubber bifins with long, wide blades, such as the Italian "Giant" and the Bulgarian "Sadala Gigant". While speed went up, the heavy weight of these fins was slowing athletes down. By 1962, many members of the USSR national team were using "Sadala Gigant" fins. Later O. Serov from Moscow made a mold copying the Bulgarian fins and started producing Soviet versions, though they fell short of the original, likely due to poor rubber quality. 

By this point, experience proved a simple rule: the longer the blade (up to a certain point), the higher the speed. 

Athletes unhappy with standard rubber fins began building their own high-speed gear, tweaking blade size, shape, weight, and elasticity. Between 1964 and 1968, B. Popov from Estonia and other Soviet athletes lengthened standard rubber blades using thin, springy steel strips (0.5 to 1.5 mm thick) coating them with thin rubber [4]. The authors of this paper used old phonograph springs for this, coated the long blade in raw rubber, and vulcanized it at the Tomsk rubber footwear factory. These blades initially reached 80–90 cm in length and we trimmed it with scissors. 

The first official European Championship with fin-swimming and diving took place in Italy in 1967. S. Tarasov from Pskov took gold in the fastest event, diving 40 m in 18.30 seconds. Shortly after, at the 1968 USSR Championship in Alushta, M. Filippenkov from Moscow dropped the 40 m time to 14.8 seconds using very long blades. 

In 1968, V. Zagozin, A. Salmin, and B. Samokhin from the SKA Red Army club in Novosibirsk optimized weight vs blade area vs elasticity by reinforcing bifins with profiled "forks" made of bronze and later of titanium alloys (USSR Inventor's Certificate 272114, 1970) (fig.3)[5]. Making these forks was complex: one had to cut them from sheet metal and precisely mill or grind them down along its entire length to a gradual taper for optimal rigidity. These titanium reinforced fins performed brilliantly, dominating in 1968 and 1969. Several athletes raced successfully with them at the summer 1968 USSR Championship and 2nd European Championship in Alushta. 

In 1968–1969, V. Zhdanov, V. Titov, and A. Shumkov (all 3 from the SKAT club in Tomsk university) made a major breakthrough still in use today: they lightened the long fin, ditched the massive rubber blade, and simplified production by using FR4-style glass-reinforced epoxy laminate first for the fork and later for the entire blade (USSR Application 1488511/28-12, 1971) (fig.4)[6]. 

fig 3 fig 4 (see original paper and see pic 4 "fiberglass laminate fork" below)

Using strain gauges and experimental test bench, the authors proved that fiberglass laminate offers superior strength, elasticity, and fatigue resistance compared to metal, while being much lighter and easier to machine. A fiberglass laminate sheet consists of pressed together glass-cloth layers that can be manually cut with a knife and peeled apart layer by layer, allowing to easily taper the thickness for the exact stiffness profile. 

The authors first tested such fiberglass-fork bifins at a competition in Tomsk in October 1968, then in Riga in February 1969, and at the 10th Russia Championship in Saratov in June 1969. In Saratov, national team member A. Kryukov tested them out of competition and posted near-world-record times. Fiberglass-bladed fins were suddenly available to everyone!

At the 1970 Russia Spartakiad in Gorky, A. Shumkov swept five distances in these fins, set three world records at the 1971 European Championship in France, and took two golds at the 1972 European Championship in Moscow. Most world records from 1970–1971 were set using these Tomsk fiberglass bifins. 

The SKAT team won the 1971 Russian Underwater Orienteering Championship in these fins. N. Turukalo (from Ust-Kamenogorsk) became the absolute USSR orienteering champion in Ignalina (1971) using them, A. Salmin took the absolute European title in the Netherlands (1972), and A. Salmin won the absolute world title in Yugoslavia (1973). 

Another approach was the monofin mimicking fish tails. In 1946, Austrian Kurt Schaefer strapped two short fins together with an insert [7]. In 1955, Germans Kurt Ristan and Hans-Joachim Bergann invented a rubber fin featuring a wide blade and a double foot pocket (BRD, pat. 1085798, 1960) (fig 5)[8], though it was just for recreation. 

In 1968, coach E. Rekson from Leningrad glued two standard rubber fins side by side onto a solid rubber sheet, and his student O. Tikhonenko won a junior USSR diving event in them [4]. The speed gain was fortunately minimal due to the small blade area, so the design didn't catch on, though athletes were already successfully doing simultaneous "dolphin" kicks in bifins. USSR Championship winners An. Ivanov from Moscow (1964) and V. Bavrina from Leningrad (1968) and some others swam this way. 

In autumn 1968, coach B. Porotov ("Altai" club, Ust-Kamenogorsk) built a high-speed twin fin and he coined the "monofin" word [9][10]. It featured an 80 cm long trapezoidal blade cut from a 2 mm industrial grade rubber sheets, reinforced with three wide strips cut from a 2mm OT-4 titanium alloy sheet (94%Ti-4%Al-1%Mn-1%other) and tapered from 2 mm down to 0.5 mm at the tip (fig 6). 

fig 5 fig 6 (see original paper and see pic 6 "titanium fork" below)

Porotov's trainee N. Turukalo debuted this monofin at the 1969 USSR Speed Championship in Kiev, winning two short-distance golds. In 1970, she used it to smash four world records at the USSR Spartakiad in Minsk and win three events at the European Championship in Spain. T. Agafonova from Rostov-on-Don also swam in a monofin in Minsk, taking second behind Turukalo in the 100 m scuba event (with a 3.7 seconds difference). The monofin for T.Agafonova mas made by her trainer A.Samosudov. Italian Franco Pavone also built a narrow monofin in 1969 by joining two bifins and lengthening them with metal strips. 

In 1971, N.Turukalo won two golds at the USSR Championship in Tashkent and three golds at the European Championship in France using Porotov's monofin, setting world records. 

At that same 1971 European Championship in France, A. Salmin won the 40 m dive with a 14.10-second world record using a self-made monofin featuring a long rectangular blade with a "seven-tooth fork shape" cut onto the fiberglass laminate using the Tomsk team's tech [11]. The monoblade replicated two adjacent fiberglass bifins design of the SKAT club. He first debuted this record-breaking design at the USSR Armed Forces Championship in Moscow in 1971. Ever since, every single speed record in underwater sports has been set exclusively in monofins. 

Athletes and coaches soon shifted to making solid monofin blades out of profiled fiberglass using Tomsk tech, dropping the rubber coating entirely. Blades got wider and shorter, looking increasingly like dolphin or fish tails (fig 7)[12]. 

Foot pockets cut from standard molded fins were attached to the monofin blades. By the 1971 USSR Cup, all top sprinters in USSR have  already testing monofins. By early 1972, all elite Soviet and some international swimmers were racing middle and short distances in similar monofins. At the 1972 Moscow European Championship, Sh. Karapetyan (Armenian SSR) won the 50 m dive in 17.0 seconds using a monofin built just days prior by his coach L. Almasakyan and B. Porotov. Soviet team members I. Avdeeva, V. Volkov (SKAT club, Tomsk), and other athletes swept all gold medals and broke world records using fiberglass laminate monofins. Within a couple of years, athletes used them for sprints and stayer events alike. Leading athletes worldwide adopted them, mostly made by Soviet makers. Small manufacturers popped up, handcrafting hundreds of these simple designs. Solid fiberglass laminate (and later carbon fiber) blades became the undisputed standard for speed. 

N. Turukalo also brought the fiberglass monofin to underwater orienteering, winning all disciplines world champion title at the 1st World Championship in Yugoslavia in 1973. 

In 1977, V. Zhdanov, V. Titov, and A. Shumkov filed a patent for a fin where the blade and foot pocket sit at a 10–20 degree angle to each other (USSR Application No. 930-13276, 1977)(fig.8)[13]. This kept the foot comfortable while driving more pressure directly into the blade. 

Finswimming was recognized as an Olympic sport in 1986, boosting both sport popularity and equipment manufacturing. Through the 1980s and 1990s, industrial production kicked off in the USSR ("Dolphin" by NPO Altai), Italy (Mat-Mas), Germany (Dol-fin), Japan (Osomoto, Sea Wolf), China, etc. 

fig 7 fig 8 (see original paper link above)

Industrial presses allowed whole profiled blades to be stamped out in one piece—a massive technological leap. In 1993–1994, Zhdanov and Titov cooperated with R&D dept. at the Dzerzhinsk plant Moscow region, to press fiberglass blades reinforced with carbon fiber fabric, upgrading performance. The catch was the high cost of carbon cloth. Still, production of carbon blades started in China and France in 1996, and Italy in 2000. Because mass-produced monofins didn't fit best specs, elite athletes still rely on custom, handmade gear. 

In 1989, Zhdanov, Titov, and Shumkov designed the "wing" monofin, adding a symmetrical elastic porous thickening on top and bottom of the fiberglass blade that acted like a biconvex hydrodynamic wing (USSR Inventor's Certificate 1771776, 1992) (fig 9)[16]. 

This shape improved water flow across changing angles of attack, deforming the thickenings into an asymmetrical profile. This generated extra force on both the up and down kick, acting similarly to an airplane wing, but to boost propulsion in this case. Tests on rig and in pool proved a significant increase in a swimmer's thrust. The "wing" concept is used elite fins today. At the 2009 World Championships in Russia, Chinese athletes did well in wing-type fins, and P. Kabanov (Novosibirsk) set a 50 m dive world record of 14.16 seconds. 

E. Andronov from Smolensk, made a next generation monofin, by redesigning the foot pocket to be heavy, tightly streamlined, and comfortable. Athletes won the 1996 World Navigation Championship in these. Between 1998 and 2000, E.Andronov (he moved as trainer to SKAT Tomsk) launched his new "HyperFins"  enhanced performance model [19], featuring a 10–20 degree feet to blade angle, streamlined shape, and a complex multi-layer foot pocket made from five rubber types. However, it is very complex to manufacture (RU Patent No. 85350 U1, 2009) (fig 10)[20]. 

fig 9 fig 10 (see original paper and see pic 10 "foot pocket fairings" below)

HyperFins pulled together all prior breakthroughs: foot pocket fairings, profiled fiberglass blade, "wing" elements, and angled pockets. Though heavier, they have neutral buoyancy. This fin shifted swimming technique once again. Prices hit $1,000. 

M. Maksimov from Tomsk tested early HyperFins at the 2000 World Championship in Spain, winning gold and setting a 400 m world record. Since 2009, virtually all top athletes have raced in HyperFins.

Results of winners in official men's pool diving competitions (all winners are Soviet and Russian athletes, see names and events in the original paper link above) 

+------+----------+----------+----------+

| Year | Dist.    | Time     | Speed    |

|      | (m)      | (s)      | (m/s)    |

+------+----------+----------+----------+

| 1959 |   40     |  22.0    |  1.81    |

| 1961 |   40     |  19.7    |  2.03    |

| 1967 |   40     |  18.30   |  2.18    |

| 1968 |   40     |  15.9    |  2.51    |

| 1971 |   40     |  14.10   |  2.84    |

| 1972 |   50     |  17.00   |  2.94    |

| 1976 |   50     |  16.92   |  2.95    |

| 2004 |   50     |  14.18   |  3.52    |

| 2009 |   50     |  14.16   |  3.53    |

| 2019 |   50     |  13.70   |  3.63    |

+------+----------+----------+----------+

Each of the fin design stages [21-24] described above led to significant increments in swimming speed. Over 57 years from 1958 to 2019, men's sprint diving speeds increased 2.5 times, from 1.4 to 3.6 m/s. For comparison, dolphins hit over 10 m/s. Until 1970, top times were set in bifins; A. Salmin set the first monofin world record in 1971, and P. Kabanov set the 2019 record (last to date for this paper edit). 

While CMAS ended up stating limits on blade measurements, physical reality and swimmer biology already set the practical cap, meaning no radical design breakthroughs have shaken up the monofin design in the last 20 years. 

Handmade HyperFins alternatives are built worldwide: by Waterway, Sharkfin, Yakovlevfins, Starfins, and Goldfin in Ukraine; Leaderfins and Arsenal in Estonia; Powerfins in France; and by Russian specialists. Andronov notes that some makers skip proper tech or use bad rubber, leading to injury risks. In 2019, about 400 HyperFins-style monofins were produced globally for finswimming, orienteering, and freediving. 

In 2007, CMAS added "classic fins" (i.e. bifins) back into competition. CMAS approved Hungary's Najade bifins made since 2000s, similar to the 1990 fins with a heel strap by Zhdanov, Titov, and Shumkov (inventor's certificate SU 1643026)[25]. Today, O. Pudov's short Powerfins are also very popular and officially approved by CMAS. 

Ultimately, tracing fast fins shows how simple rubber fins gave way to complex composite designs with refined foot pockets and advanced carbon-fiber blades, all backed by hard science. The quest for speed continues. 

References 

1. De Corlien, L.M. (1993) (in French) Swimming and rescue thrusters. FR, Pr.1933; FR, pat. No 767013(A), 1934. Kl. A63V31/08.

2. Titov, V.B., Zhdanov, V.V., Kochetkov, A.D. et al. (1990) (in Russian) Research of foreign and Russian experience in the design of molded and composite monofins and bifins: report on the research work at Tomsk State University. Vol. 1. Tomsk: Tomsk State University.

3. Owen, R. (1940) Churchill. Swim-Fin. USA, Filed 1940, pat. No 2321009, 1943. Kl. NKI 9-309.

4. Prapor, S.S. (1980) (in Russian) From the history of fins. Sportsmen-podvodnik. 60. pp. 10–13.

5. Zagozin, V.A., Salmin, A.M. & Samokhin, B.G. (n.d.) (in Russian) Flippers. USSR AS No 272114, Kl. A 63b 31/08. BI. No 18, 1970.

6. Zhdanov, V.V., Titov, V.B. & Shumkov, A.D. (1971) (in Russian) Fins with an elastic element. USSR application No 1488511/28-12.

7. Andres-Brummer, D. & Maric, M. (2019) (in German) Monofin: Swimming and diving like a dolphin. Delius Klasing Publishing.

8. Ristan, K. & Bergann, N.-J. (1960) (in German) Swimming aid that can be operated simultaneously by both feet of a swimmer. BRD, pat. No1085798.

Kl. NKI 77a 31/10, MKI A63v.

9. Porotov, B.G. (1971) (in Russian) Mastering a new style. Sportsmen-podvodnik. 28. pp. 8–13.

10. Mazurov, I.V. (1971) (in Russian) The 1969 sports season. Sportsmen-podvodnik. 25. pp. 3–27.

11. Mazurov, I.V. (1972) (in Russian) The 1971 sports season. Sportsmen-podvodnik. 30. pp. 3–23.

12. Kerll, K.-H. (1988) Sports Committee Manual. Stuttgart: Verlag Stephanie Naglschmid.

13. Zhdanov, V.V., Ladygin, V.A., Titov, V.B. & Shumkov, A.D. (1977) (in Russian) Fins for high-speed swimming. USSR Application No 930-13276.

14. Altai Research Institute of Chemical Technologies. (1982) (in Russian) Fiberglass lminate blades for monofins and bifins. TU-84-415-96–82. Biysk: [s.n.].

15. Titov, V.B., Zhdanov, V.V., Kochetkov, A.D. et al. (1990) (in Russian) Development of the sports monofin "SKAT-Debut": report on the research work of TSU. Tomsk: Tomsk State University.

16. Zhdanov, V.V., Titov, V.B., Shumkov, A.D. & Soloviev, E.S. (1992) (in Russian) Swimming fins. USSR AS No 1771776. Kl. A1 A63V 31/11. BI. No 40.

17. Titov, V.B., Vasenin, I.M., Zima, V.P. & Kryuchkov, D.A. (1997) (in Russian) Experimental studies of the dynamics of motion of a monofin in water. In: Aleksandrov, I.A. et al. (eds) All-Siberian Readings in Mathematics and Mechanics. Tomsk: Tomsk State University. pp. 94–99.

18. Titov, V.B. & Libin, E.E. (1997) (in Russian) Leak formation during movement of a swimmer with a monofin. In: Aleksandrov, I.A. et al. (eds) All-Siberian Readings in Mathematics and Mechanics. Tomsk: Tomsk State University. pp. 100–106.

19. Andronov, E.S. (2004) (in Russian) Development of new fins - R&D for underwater sports. In: Environmental, humanitarian and sports aspects of underwater activities. Tomsk: Tomsk State University. pp. 5–7.

20. Zhdanov, V.V., Titov, V.B., Andronov, E.S. & Andronov, M.E. (2009) (in Russian) Monofin. Patent RU No 85350 U1. Kl. A63V 31/00. BI. No 22.

21. Titov, V.B. & Zhdanov, V.V. (1996) (in Russian) The history of creation and the trend of designing modern monofins for underwater sports]. In: Healthy lifestyle: essence, structure, formation on the threshold of the 21st century. Tomsk: Tomsk State University. pp. 154–159.

22. Titov, V.B. (1999) (in Russian) Patenting as an objective indicator of creative activity in the creation of fins for underwater sports. In: Ecological, Humanitarian and Sports Aspects of Underwater Activity. Tomsk: Tomsk State University. pp. 41–50.

23. Orlov, G.N. (2005) (in Russian) Evolution of a monofin as a propeller and its influence on the kinematics of the biotechnical coupling athlete-monofin in diving male sprinters. In: Underwater Sport. Current State and Development Prospects]. Krasnoyarsk: SibGAU. pp. 96–102.

24. Zhdanov, V.V. (2011) (in Russian) SKAT. Tomsk: Tomsk State University.

25. Zhdanov, V.V., Titov, V.B. & Shumkov, A.D. (1990) (in Russian) Swimming fins. Certificate SU 1643026. Kl. A1 A63V31/11, 1990.

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