The dive is called a back quad-quad. It entails starting backwards, whipping 3½ twists in the first somersault followed by two front flips and a Barani (somersault with half twist) exit. The idea came about last year, and Heslop committed to training it in January 2023.

If he does it in Fukuoka, he’s really just one-upping himself. Heslop was already doing the hardest dive on the high diving circuit last year. It, too, was a quad, but it featured a running takeoff, 3½ twists, and 6.2 DD. By adding a half twist and starting backwards, he’s ramped up the difficulty to a gob-smacking 6.6.

“There wasn’t much genius that went into it, “Heslop, 21, said of the idea. “It was either add a flip or add a twist, so we went for the [half] twist.”

Since Heslop trains at a facility that has a 20m tower (seven meters lower than in competition), he can’t train the dive regularly. So in practice, he does one fewer somersault.

The first time he ever did a full version of the dive was in February, at a training camp in Ft. Lauderdale, Florida. “I kind of landed on my face,” Heslop said, so he only managed to do one there, due to the face plant. 

Three months later at the 2023 World Cup, on the same tower, Heslop threw the 6.6 DD dive for the first time in competition – but it was only the third time in his life that he had ever performed the whole thing.

“That’s just how high diving is,” he said.

Even during that World Cup competition, Heslop said, “I didn’t know whether the dive was possible.”

“They say I’m nuts,” he said. “Yeah, I get it.”

Heslop’s coach, Stéphane Lapointe, says one main reason Heslop is the only person who has been able to do the 6.6 DD dive is his twisting ability.

“He’s a very fast spinner” he said, which, in part, might have to do with Heslop’s arm position. Lapointe said Heslop twists like a trampoline athlete, bringing both arms in close to his center of gravity.

Other divers, like the Romanian gold-medal favourite Constantin Popovici, will twist with one arm bent above his head and one arm bent below it. In contrast, Heslop brings both close to his rib cage. Heslop’s other advantages include the Brit’s 5-foot-11 frame, long arms, high center of gravity and – perhaps most of all – spatial awareness.

But until Heslop gains consistency with the dive, however, he’s not only taking a risk in the air but also on the scoreboard.

Ultimately, whether we see the hardest high dive in the world in Fukuoka will come down to strategy.

Will he back off and go for 10’s? Go for broke, max out his degree of difficulty, and hope that his scores multiplied by the DD will put him on the podium?  Or perhaps, knowing Heslop, maybe he will unveil something totally new that all his quad-quad training made possible.

One thing is certain. Heslop said that if he does the 6.6, it will be on the final day of high diving competition: Thursday, July 27.

HOW THE DIFFICULTY STACKS UP ON QUAD VARIATIONS

Heslop’s (6.6 DD) back 4 somersaults + 4 twists

Heslop’s (6.2 DD) forward 4 somersaults + 3½ twists

Popovici’s (5.8 DD)  back 4 somersaults + 3 twists