Heidi Klum was terrified when her son Henry got caught in a rip current in Hawaii recently.

The seven-year-old boy got into trouble while swimming with his nannies on holiday and had to be rescued by Heidi and her boyfriend Martin Kristen but Heidi, 39, has praised Henry for remaining calm during the terrifying incident.

She told chat show host Ellen DeGeneres: ''It was so scary. I mean it happens in a second.

''He is a really good swimmer. He is very strong, and I guess because he is really athletic he knows how to swim so well. Henry said, 'Well, you always told me when you're in the water you have to be really calm and you can't stress out and that's what I did.'''

While Henry's ordeal didn't last long, Heidi - who also raises children Leni, eight, Johan, six, and Lou, three, with estranged husband Seal - revealed it was harder to save the nannies as they got dragged out further by the current.

She said: ''For the adults, it was really hard for them to get back out. The waves were just all of the sudden taking them deeper into the ocean. It's really wild.''