Marco, an accomplished athlete residing in Italy, has made significant strides in open water swimming. He began his journey in Denain, France, at age seven and transitioned to open water swimming at 15. His father and brother were swimmers, which influenced his choice of sport. Coach Eric Boissiere invited him to try open water swimming, and he appreciated the strategic aspect of the sport.

| Season | Event | Rank |
|---|---|---|
| 2021 | Men's 10km | 6 |
| 2016 | Men's 10km | B Bronze |
In December 2017, Marco sustained a sacrum fracture during the World Military Championships. He also faced a bicep muscle injury at the beginning of the 2017/18 season, which halted his training for two months. Additionally, a bone marrow oedema in his left foot disrupted his preparation for the 2017 World Championships in Budapest.
Marco became the first French male open water swimmer to win a world title by securing gold in the 5km event at the 2017 World Championships in Budapest. His bronze medal in the 10km event at the 2016 Rio Olympics was France's first Olympic medal in open water swimming.
Marco has received several accolades throughout his career. He was named Male Open Water Swimmer of the Year by SwimSwam in 2020 and by LEN in 2017. The International Swimming Federation awarded him Best Male Open Water Swimmer in 2017. In 2016, he was named Knight of the Order of Merit by the French government.
Marco's partner, Oceane Cassignol, is also an accomplished open water swimmer who won gold as part of the 5km mixed relay team at the 2017 World Championships. Marco aims to compete at the 2024 Olympic Games in Paris and aspires to become an Olympic champion in open water swimming.
After finishing sixth in the 10km event at the Tokyo 2020 Olympics, Marco parted ways with long-time coach Philippe Lucas. He briefly trained with Fred Vergnoux in Spain before relocating to Italy to train with Fabrizio Antonelli. Marco had previously followed Lucas from Narbonne to Montpellier in France.
Marco's journey is marked by resilience and determination. His achievements and future ambitions reflect his dedication to excelling in open water swimming.
Marco, an accomplished athlete residing in Italy, has made significant strides in open water swimming. He began his journey in Denain, France, at age seven and transitioned to open water swimming at 15. His father and brother were swimmers, which influenced his choice of sport. Coach Eric Boissiere invited him to try open water swimming, and he appreciated the strategic aspect of the sport.