updated 04/03/2013 AT 10:00 AM ET
•originally published 04/03/2013 AT 11:20 AM ET
“People are used to seeing me on the beach in a bikini, smiling with the wind in my hair,” Klum, 39, tells PEOPLE exclusively of the scary scene, in which her son Henry and two nannies began to struggle in the powerful ocean current.
“These photos taken recently look much worse that it really was that day. I did what any mother would do,” Klum, who jumped into action with boyfriend Martin Kirsten, says. “Henry swam out of it. I grabbed him at the shore. The nannies were the ones in much deeper trouble.”
Continues Klum: “Never underestimate the power of the ocean.”
A friend adds that the family was surprised they “were being photographed and no one would come help.”
After the frightening incident, Klum and her family arrived home safely in Los Angeles on Monday.