Indeed, only five people only ever competed in the sport and the world Olympic record is unlikely to ever be beaten.
The distance plunge defied the usual conventions of athletics. It didn't require superhuman strength, endurance, agility, speed, or even creative flair – in fact, apart from an initial dive, any form of exertion was strictly prohibited. But most of all, it was also, according to many contemporaries, paint-dryingly dull to watch, and holds the dubious distinction of having been labelled the weirdest and most boring Olympic sport of all time. The event has been derided as "competitive floating".
Like all sports, it had rules. The competitor began with a regular standing dive. This was the "plunge", and it was done from a height of 18 inches (46cm), without a diving board.
Once the competitor had hit the water, they had to keep their body perfectly still - they could not move a muscle or propel themselves in any way. After a slow glide underwater, the plunger inevitably bobbed up to the surface, where they would continue to float passively, arms outstretched, hoping to rack up a few more inches. As they wafted along, there was so little action, athletes could have been mistaken for having fallen asleep.
There were two ways of assessing performance: the winner was either the person who travelled the furthest before they were forced to raise their face to breathe, or the competitor who achieved the longest distance within one minute.
The first and only time the 'sport' was included in the Olympics was in 1904, staged at Forest Park in St Louis, Missouri. Five people took part in the "formidably soporific" event that was eventually won by American William Dickey who cruised along for 62ft 6in (19m) to win gold. He didn't know it at the time, but this would be the best Olympic plunge performance in history.
Meanwhile, at the other end of the sporting spectrum...