The 39-year-old 'America's Got Talent' judge was vacationing with her children Leni, eight, Henry, seven, Johan, six, Lou, three and Kirsten, reported Us magazine.
"We got pulled into the ocean by a big wave. Of course, as a mother, I was very scared for my child and everyone else in the water. Henry is a strong swimmer and was able to swim back to land. We were able to get everyone out safely," Klum said.
"Since they began dating last summer, the pair have gotten serious. She loves her life and enjoys sharing it with Martin who treats Heidi and Seal's kids like his own. She's able to focus on her career because Martin takes great care of them and enjoys staying in the background," a source said.