He was born in Athens in 2009. He started water skiing at the age of 7 as an athlete of Nautical Club of Vouliagmeni, where he still competes today – the leading club of the sport in Greece.
Family Tradition
Following in the footsteps of his father, Lefteris Kousathanas, a multiple-time Greek champion and today one of the top Senior athletes in Europe.
He also follows the path of Pola Kousathana and Matina Kousathana, his two older sisters, who were and still are water ski athletes as well.
Coaches
A Leading Athlete Since the Age of 9
Yiannis Kousathanas has been a standout athlete since the very beginning of his career and continues to dominate both nationally and internationally, collecting titles and distinctions.
He holds the majority of the Greek national records since the age of 9, with performances that rank him among the world’s top athletes in his age category, consistently holding positions within the top three globally.
Consistently Winning Medals in Major Competitions Since 2022–23
Over the past four years, Yiannis Kousathanas has consistently stood on the podium in major international competitions.
2023 European Youth championship in Spain
- 3rd in slalom
- 2nd in jump
- 3rd in overall
2025 European Youth championship in Spain
- 2nd in slalom
2026 Under-17 World Championships in Argentina
- 1st in slalom
- 1st in jump
- 2nd overall
- 4th in tricks
Among the Best in the World in Every Event - World Ranking List
Yiannis Kousathanas consistently ranks within the top three (1–3) in the world ranking list across all water skiing disciplines, proving that the future belongs to him — in Slalom, Jump, Tricks, and Overall.
Two-Year Preparation Plan Leading to 3 Medals at the World Championships in Argentina
The three medals won by Yiannis Kousathanas at the World Championships in Argentina were the result of a carefully designed two-year preparation plan that began exactly two years earlier, involving extremely hard training, numerous international competitions, and intensive preparation.
Injury That Changed Everything Before the “Golden” Triumph
A spinal injury suffered by Yiannis Kousathanas last August completely disrupted the entire preparation schedule and added tremendous pressure.
The young athlete stayed away from training for two months, followed by another two months filled with uncertainty and stress. However, since last January (2026), everyone focused on the final preparation phase for the Argentina World Championships, where the Greek champion ultimately dominated.
Alongside him throughout this journey, making a decisive contribution to his development, was Vasilis Vlastakis, who played an important role in shaping his athletic career.
An Expensive Sport Without State or Federation Support – Parents and Clubs as Main Sponsors
Water skiing is an extremely expensive sport.
It requires a boat, a driver, a coach, fuel, while the training facilities are located far from Athens, at Lake Stratos near Agrinio.
The expenses are enormous, and neither the State nor the Federation is able to fully cover them.
As a result, the greatest burden naturally falls on the clubs (in Yiannis Kousathanas’ case, the Nautical Club of Vouliagmeni) and especially on the athletes’ families, who support the skiers in every possible way.
