underwater swimming

Did you know: Swimmers must not remain submerged for more than 15m

It’s 1988 in the United States. A young student from Harvard, David Berkoff, prepares to unveil his latest swimming innovation to the world.


Considered to be a strong backstroke swimmer, he entered the 100m backstroke in the American qualifiers for the Seoul Olympics. He won his races, setting two new world records, with a best time of 54.91 seconds.


The secret to his success? An exceptionally long distance covered underwater, with wave-like movements reminiscent of a marine mammal!


On that day, David Berkoff spent most of his races underwater, surfacing 40m into his first length, and 20m into the second. Our dear David only actually swum “normally” for 40 metres.


In view of the American’s outstanding performances, this extreme technique was soon adopted by other top-flight swimmers.


But then the International Swimming Federation (FINA) stepped in...





The situation had already been observed at the 1956 Olympics in Melbourne. Japan’s Masaru Furukawa won Olympic gold by swimming the 200m breaststroke underwater, only coming up to breathe in the turns. An unhappy FINA reacted by condemning underwater breaststroke, which was not much of a spectacle and could put the swimmer’s life in danger.


Not long after the young American David Berkoff’s triumph, FINA got tough by slamming a 10-metre limit on the distance covered underwater after a turn. In 1991, the underwater distance was lengthened by 5 metres.


In the years following the feats by the Japanese and American swimmers, other strokes (butterfly, crawl) also discovered their own underwater experts, and FINA came up with appropriate restrictions. Today, swimmers still cannot remain submerged for more than 15 metres after a turn.


To remove any ambiguity, and to allow the stewards to do their job properly at competitions, it should be noted that this 15-metre limit (shown by a line hanging above the pool) is measured to the swimmer’s feet, not the head.


In other words, any swimmers who fancy a spot of free-diving, and who do not surface before their feet have crossed the 15-metre line, are immediately disqualified.


This limit is still frequently challenged, giving rise to numerous debates amongst swimmers and coaches.



But is there a real difference between the speed of surface swimmers and “deep-sea divers”?





If you watch Jérémy Stravius or Michael Phelps in action, you will agree that this difference is not minimal. In fact, it is clearly visible!


After being tested by certain swimmers, observed by countless trainers and analysed by numerous scientists, underwater swimming no longer holds any secrets. The conclusion indisputable: swimmers go faster underwater than on the surface.


By way of comparison, a skilled underwater swimmer goes faster than the top speed reached by 50-metre crawl swimmers! And since the crawl is the fastest of the four strokes, one can well imagine the advantages of well executed and well used underwater swimming.


So what is the reason for this aquatic velocity?


First, when swimming at depth, a number of factors that slow down forward movement are avoided, allowing for high-speed swimming at a moderate effort. When in the water, the body is subject to several restrictive forces.


The first is due to the friction of the water on the body. This friction is produced, in particular, by surface movements that bring the swimmer’s body into contact with a greater surface area of water.


The second obstacle encountered in water is form drag. This could also be called hydrodynamics. Since water is much denser than air, its resistance is 1,000 times higher than that of air. When a swimmer is underwater, his position favours penetration into the masses of water, thereby producing more efficient gliding than on the surface.


Last, but not least, comes wave drag. Swimmers at depths greater than 50cm avoid wave drag. The energy dissipated by surface waves slows down forward movement. By passing beneath this turbulence, underwater swimming is more efficient.



So as you can see, just like the man from Atlantis, if you want to race with fish, grow some gills and swim underwater!





As we have already said, the regulations on submerged swimming are a subject of numerous debates.


Some people in the world of competitive swimming believe that the regulations applying to freestyle races (as the name suggests) should be less restrictive, in order to add some more spice and encourage innovation.


Just imagine the unbearable suspense amongst the spectators, as they wonder whether their favourite swimmers and their competitors will opt for a conventional swim on the surface, or for swimming underwater, as the race approaches. Maybe this would add even more intensity and visual impact to the already magnificent sport of swimming?


But questions other than mere aesthetics must also be addressed. Would this still be swimming at all? Would the swimmers’ lives be in danger?


We all know that swimming is a fast-changing sport. Not long ago, FINA changed the rules of relay races. So, when it comes to submerged swimming, will the Federation strike a compromise by one day accepting fewer restrictions on freestyle events, like at the Olympics at the start of the 20th century.



And what about you? Do you like it on the surface, or underwater?

National Swimmer & Dialogue Leader