An Olympic star made a splash when he dropped in on a children's swimming team during their weekly session.
Swimming champion Mark Foster treated the Hertsmere Flyers Swimming Club, at The Venue, in Shenley Road, Borehamwood, to a surprise visit.
Foster, who retired from swimming in 2008, has swum in the Olympics five times and has eight Commonwealth medals. He is also the British record holder for the 50 metre freestyle and 50 metre butterfly crawl.
Hertsmere Flyers Swim Club head coach Luke Dormer said, “It was such a treat for the swimmers to listen to Mark give some expert advice and tips.
“When you hear it from someone who has achieved so much in the pool it is truly inspirational and will be remembered for a long time.”