Cyril says windsurfing is like a mixture of several different sports -- a combination of the laidback nature of surfing and the formality of sailing.
"It's tricky because you have the freedom of a wild sport, but on the other side you have the sailing part," he says. "It's mixing between the two so you have the free spirit of 'party' and enjoying life, and the sailing part is more strict and more square."
Exerting all parts of your body is the norm and like skiing, different disciplines exist. The oldest Moussilmani brother spends three to five hours a day on the water and puts in 10-15 hours a week in the gym.
The website of the Professional Windsurfing Association lists rankings in slalom, freestyle and wave but competitors can participate, too, in super x -- combining freestyle and slalom -- and speed.
Windsurfing retained its Olympic status after originally being replaced by kiteboarding, although Cyril doesn't expect to be in Rio in three years because the board used is different to the one he trains with.
He began competing in earnest as a 16-year-old in Australia and has tried his hand in many of the sport's formats, concentrating on slalom for competition and wave for fun.
But despite enjoying his travels, Moussilmani is always happy to be back in Marseille.
"I like to stay home because we have a lot of wind almost all year," he says. "Maybe in the summer it's a little tricky because it's very warm and a lot of people are on the beach, but during the rest of the season it's a very clement place to windsurf.
"When we have big storms we have waves, but most of the time it's choppy, so that's the only bad point about Marseille. But around Marseille there are two or three spots where you can do waves in proper conditions and you can travel as well.
"I like to go when it's super-strong wind and just be on the edge. When I do wave I like to show to everybody what we do -- we jump very high and we do loops. I like to be a little bit like a showman."