Finswimming

Mostly swimming's officiating, with two additions that are unlike anything else on this site.

The familiar half: touchpads, lane judges, starters, false-start detection and turn judges, all working as they do in swimming. Times to the hundredth, records ratified per discipline and per distance.

Surfacing. In apnea events the swimmer must remain underwater for the whole 50 metres. Any break of the surface ends the race, and judging it is a binary observation of a swimmer who is deliberately invisible for the duration. It is the only race on this site where being seen is the infringement.

Equipment inspection. Because the monofin is capped by dimension rather than standardised, fins are measured before competition — surface area and dimensions checked against the limits. A sport that permits equipment variation has to police the boundary of that variation physically, and finswimming does it with a ruler.

The immersion discipline adds a third: the breathing set must be an open-circuit configuration of the permitted type, which is a technical-diving inspection performed on a racing athlete.

What none of this instruments is the technique itself. The undulation that makes the sport fast is not judged at all — there is no equivalent of swimming's stroke-legality rules for breaststroke or butterfly, because there is only one way to drive a monofin and no incentive to do anything else.

Finswimming's map looks nothing like swimming's, and the difference is institutional rather than aquatic.

The historic powers are Russia and Ukraine, whose Soviet-era development of the monofin and of the sport's technique still shows in results; Italy, one of the sport's founding centres; Hungary, Greece and Spain; China, which has invested heavily; and Colombia, which is the most striking case — a country with a modest swimming record and a genuinely world-class finswimming programme.

None of that follows the map of swimming strength. Australia and the United States, which dominate swimming, are marginal here. The reason is that finswimming grew inside CMAS-affiliated diving federations, so the sport took root where those federations were active and funded, not where pools and swimming clubs were most numerous.

That is an unusually clean example of a phenomenon this site keeps finding: a sport's geography is often a map of which institution happened to adopt it rather than of who is best placed to play it. Fistball follows German emigration. Sepak takraw follows childhood exposure. Finswimming follows diving federations.

The facility requirement is the ordinary one and it is a real constraint: a 50-metre pool with lane time available, which is contested everywhere. Where finswimming has to share water with a strong national swimming federation, it generally loses.

Finswimming exists because a diving federation decided to hold races.

CMAS — the Confédération Mondiale des Activités Subaquatiques — was founded in 1959 to govern underwater activity broadly: diving instruction, underwater photography, scientific and technical work. Jacques Cousteau was its first president. Racing was one item among many, and the sport that resulted carries the fingerprints of that parentage in a way nothing else on this site does.

Look at the disciplines. Surface is a pool race swum face-down with a snorkel. Apnea is a pool race swum entirely underwater on a single breath. Immersion is a pool race swum underwater carrying an open-circuit compressed-air cylinder. Those are not three formats of one event; they are three answers to the question of how a person breathes, and only a federation whose primary business was being underwater would have organised a racing sport that way.

The monofin is what made it fast. A single blade worn on both feet, driven by a whole-body undulation, moves a swimmer through water substantially quicker than any stroke — finswimming is the fastest human-powered movement in water there is. Development through the 1960s and 1970s, particularly in the Soviet Union and in Italy, turned a diving aid into a racing implement.

The first world championships were held in 1976, codifying the disciplines the sport still contests. Finswimming has never been on an Olympic programme, in any form, and is contested at the World Games.

This is the sport where the equipment question has no exit.

The monofin is a single large blade worn on both feet. It converts a whole-body undulation — chest, hips, legs, blade — into propulsion far more efficiently than kicking with separate feet, and it is the reason finswimming is quicker than swimming over the same distance. Blades are made from composites and glass fibre, vary in stiffness and profile, and are matched to the athlete and the distance.

CMAS regulates it by dimension: maximum surface area and dimensions are capped, materials are broadly open. That choice is the whole story, and it is worth setting against the two other answers this site records.

• Swimming, faced with polyurethane suits in 2009, banned the suits and let the records stand. Several are still unbeaten.
• Athletics, faced with a javelin flying too far, redesigned the implement and reset the record book.
• Finswimming could do neither. Ban the fin and there is no sport. Redesign it to a single standard and you remove the athlete's ability to match equipment to their own undulation, which is a real part of the craft.

So it capped the dimensions, left the materials open, and split the record book by fin type: monofin records and bi-fins records are kept separately, because two conventional fins and one large blade are not the same event.

The other equipment follows the discipline. A large-bore centre snorkel for surface events, so the head never lifts. Nothing at all for apnea. An open-circuit compressed-air cylinder for immersion, carried through the race — the only racing event covered here in which the athlete brings their air with them.

Finswimming's governance problem is that it is a swimming sport and swimming's federation has nothing to do with it.

CMAS governs finswimming as one activity among many underwater pursuits. World Aquatics governs swimming, diving, water polo, artistic swimming and open water. The two sports share a pool, a lane, a touchpad, a start and a timekeeping convention, and are institutionally unconnected.

That matters for a specific reason. When a sport wants a place on a multi-sport programme, it competes against sports in its own category, and finswimming's category is already fully occupied by a federation with five Olympic disciplines and a century of standing. A pool sport arriving from the diving federation has no obvious route in.

CMAS's own priorities are also not primarily competitive. It certifies divers, sets technical standards, and runs scientific and environmental programmes; a racing discipline is a smaller part of its work than finswimming's athletes would like. This is a milder version of the tension recorded on this site for lifesaving, whose federation is a drowning-prevention body first.

Where finswimming has done well is the World Games, which is the intended home for exactly this kind of sport: organisationally mature, genuinely international, and with no plausible Olympic path.

The sport's geography reflects a further political inheritance. Its historic strength is in Russia, Ukraine, Italy, Hungary, China, Colombia and Greece — substantially the countries where state or club diving federations invested in racing, rather than the countries that are strongest in swimming.

Capping the fin. The recurring one. Monofin design advanced quickly once the sport was competitive, and an unregulated blade would have made equipment the only variable that mattered. CMAS capped surface area and dimensions and left materials open — a partial answer that keeps equipment selection in the sport, deliberately, and is periodically argued about for exactly that reason.

Splitting bi-fins off. Two conventional fins and one monofin produce different speeds and different techniques, and pooling them would have made one of them pointless. The sport separated them into disciplines with separate records rather than choosing between them — the same instrument powerlifting used for raw and equipped, and cycling for the hour record.

Apnea safety. Racing 50 metres underwater at maximum output on a single breath carries a hypoxic blackout risk, and the supervision requirements around apnea competition exist because of it. It is the sport's real safety question and it is handled by protocol rather than by changing the event.

Immersion and the cylinder. An event in which the athlete carries compressed air raises equipment questions no other racing sport has: cylinder type, valve configuration and what counts as an open circuit. The rules are technical diving rules imported into a race.

Which federation should govern it. Not a rule change and arguably the sport's largest structural issue: a pool racing sport administered by an underwater-activities body, in a world where the pool federation is one of the most powerful in the Olympic movement.

Recorded as unsettled.

How much the fin should be allowed to do. Dimensions are capped and materials are open, so blade design is a live technical field and part of elite preparation. Whether that is a legitimate craft or an unpoliced performance variable is argued, and it is the same argument powerlifting has about supportive equipment.

Whether the record books should stay split. Monofin and bi-fins, surface and apnea and immersion — the sport keeps several books, which is honest and which fragments an already small competitive field.

Which federation should govern a pool sport. Finswimming is administered by an underwater-activities body while the pool is institutionally owned by another federation entirely. Nothing about this is likely to change, and it constrains every ambition the sport has.

Apnea's risk. Racing underwater at maximal output on one breath carries a blackout risk managed by supervision protocol rather than by altering the event. Whether that is sufficient is a question the sport revisits.

Olympic prospects. There are none in view. Finswimming is faster than swimming, contested internationally since 1976, and has no path onto a programme where the aquatic slots belong to somebody else. The World Games is, realistically, the ceiling — which the sport has largely accepted, and which makes it one of the more clear-eyed federations covered here.