For the 1997 World Rowing Championships, Gentili was two months old.

Italy's Elia Luini was in the lightweight men's single sculls 18 years ago, while Julia Levina of Russia raced in the women's single sculls and raced again in that boat in 2015. There was also Great Britain's Katherine Grainger. In 1997 she scored bronze in the women's eight. For 2015 she raced in the final of the women's double sculls.

Norway's Olaf Tufte was in the men's quadruple sculls, finishing 13th in 1997. Two Olympic Championship titles later, Tufte raced in 2015 in the final of the men's single sculls.

Now 43 years old, Ekaterina Karsten of Belarus won the World Championship title in the women's single sculls in 1997. For 2015, Karsten raced in the women's double sculls with the aim of qualifying for her seventh Olympic Games. She achieved the qualification of the boat bringing her one step closer to competing at the Rio Olympic Games.

Ekaterina Karsten, Belarus, A Final, Wome_ © FISA Igor Meijer

Marcel Hacker of Germany was 20 years old in 1997. That year he won silver in the men's quadruple sculls as the junior member of his crew. Hacker then went on to become Germany's top single sculler. He medalled at the Sydney 2000 Olympic Games in the single, following it up by becoming World Champion in 2002. For 2015 Hacker raced in the men's double sculls with the new top single sculler for Germany, Stephan Krueger. In 1997 Krueger was nine years old.

"I remember it (1997) well," says Hacker. "It was my first senior World Championships and to be in a quad as a young guy with the older guys in the boat was great. It's very different now as I'm now the old one and so not the young, aggressive, think I can do anything, person."

Hacker says 18 years on he is more relaxed in his race preparation. "The preparation is the same. But in term of nerves I am much calmer now before the race. I am way more relaxed."

Hacker sees the main change in rowing in 18 years being the boat materials. "The shaft and blade is better. And the boats!," says Hacker. However, adds Hacker; "Rowing is rowing and stays the same. It demands power and hard work. You have to stay focused and to pull hard. But the technique is very different now, especially in the single. Now you push more on the legs from the catch, in front. Before was much more with the back."

As a 20-year-old Hacker never imagined he'd still be competing at age 38. "I am just happy that it is the case."

"I was the oldest in 1997. I'm still the oldest today," says Nikola Stojic. Serbia's Stojic  raced in the men's double sculls for Yugoslavia in 1997, finishing tenth overall with his 18-year-old partner. "We'd only been training together for two weeks. We had no expectations so we were satisfied with tenth."

Stojic says it is hard to remember 1997 but he does remember that the course was in a different place so the finish line was a long way from the grandstand. He also notes that the 2015 event is much, much bigger. "There were no quarterfinals in 1997."

After the 1997 World Rowing Championships, Stojic says he retired, in the end for about six months,  so he never imagined that 18 years later he would still be competing. "When I came back, the goal at that stage was to go to the Sydney Olympics. I did not think past that."

Stojic says he would have told his younger self not to train harder but to train smarter, although Stojic goes on to say he trains harder today. "I think I train more volume now. But everyone is training more now, the times are faster."

A look at the age of competitors in rowing at the Olympic Games will be published shortly.