Australian diving star Cassiel Rousseau has summoned the spirit of his Olympic-winning French grandfather as he sailed into the semi-finals of the 10m platform in Paris.

For Rousseau, world champion in 2023 in an event dominated by Chinese divers, his odyssey back in the land of his forebears has been most enjoyable as he seeks to emulate his grandpa Michel Rousseau, who was the track cycling champion for France at the 1956 Melbourne Olympics.

"We're kind of doing the old switcheroo here, the Aussie going to France instead of the French going to Australia," smiled the laid-back Queenslander after finishing seventh in prelims on Friday to qualify for the 18-man semi-final on Saturday.

"He obviously won the gold. I'm not hopeful to win a gold here, but I'm just going to keep trying my best.

"But I always feel his spirit, 100 per cent, every single competition I do, he's always with me. He was an amazing man."

The 23-year-old is one of the more fascinating figures of the Australian team in Paris, a self-confessed shy guy who's also always been an extrovert when presented with a crowd ever since he was a child circus performer and a champion acrobatic gymnast in Queensland as a kid.

From a multi-talented family, with sister Elodie once a Cirque Du Soleil performer in Las Vegas, Rousseau was in the final of Australia's Got Talent when just 11, but it was only five years later that he turned his aerial skills to diving, becoming the country's junior champ within a year.

By last year, his journey had taken him to a world title in Fukuoka, during which he achieved the rare feat of beating the two top Chinese.

But his form has dipped since then - not that this cheery figure seems too worried. He's here to have fun, he smiles.

"Of course, everyone expects great things, but I don't," he shrugged.

"I never look to get a medal. In Japan last year, it was probably my peak performance and I'm not really at my peak at the moment. Hopefully, next year.

"But obviously anything's possible. If you land on your head, you should be fine to make the final, so hopefully I'll be able to do that."

So where's the drop occurred in 2024?

"Just mentally and physically, it just hasn't been the best. It's kinda just being a human, I guess," he said.

"The aim is to have fun. I'm incredibly grateful to be here, being able to a compete in the Olympics and be able to travel so much as an athlete. I'm extremely happy with my performance."

His French roots run particularly deep, with his Parisian mum ensuring that twin Rousseau and his six siblings spoke French at home when he was young.

"It's an amazing, interesting story I have with my family in France. Just being in Paris, where mum grew up in, is just an amazing feeling, and her showing me around last week was just a good feeling."

Rousseau scored 453.10 points, way behind Chinese leader Cao Yuan's 500.15, and will be joined in the semis by 18-year-old Adelaide diver Jaxon Bowshire who performed superbly on debut to finish 14th with 390.30.