Phrases such as ‘never give up’ and ‘there is no such thing as failure’, peppered the talk to the pupils, with students enthused by the five-time Olympian.
The fastest swimmer in the country at the age of 15, Mr Foster said he remembers the influence of those who visited his school to give talks, people who would inspire him and motivate him to be better.
‘I look back when I was younger and there are certain things that have stuck with me – one being British swimming Olympic gold medallist, Duncan Goodhew turning up at my swimming club,’ he said.
‘I met people who came to my school who had an influence on me as a person.
‘I’m not saying I will inspire everyone, but it might help one or two and hopefully they’ll take something away from what I have to say.’
Barclays, who invited the swimmer to the island for a Guernsey International Insurance Association event, made the suggestion he speak to children to encourage them to be the best that they can be.
Mr Foster spoke about events from his career, which included retiring from the sport in 2006, then returning in 2007, aged 38, in a bid to try and win an elusive Olympic medal at the 2008 Beijing Games.
‘It was an honour to be the Team GB flagbearer at the 2008 Olympics.
‘To know that you have been chosen by your teammates to lead them out is the best feeling.’
Although he never managed to win an Olympic medal, he has won medals at the European, Commonwealth and World Championships, which he handed out for pupils to look at.
Students got to ask Mr Foster questions at the end of the talk.
Katie Wherry said that the talk was great and that she learned a great deal from his visit.
‘It was good to have him here visiting the school and talking to us,’ she said.
The takeaway from the day is not to be afraid of failure said Mr Foster.
‘Students should not compare themselves to anybody else, they should keep going and be the best that they can be,’ he said.