The accident happened Saturday at Gilson Park in Wilmette when Tristan Shambee, 14, was swimming with friends.
The U.S. Coast Guard says the waves were high and strong winds created dangerous conditions. Friends have told the family that Tristan hit his head on a rock and was pulled under. It took search teams two hours to find him.
"We want to remember him as being amazing. He was the one who always had a joke for us or he ran around the house chasing my sister and I or beating up on my sister or my fiancee," said Tamika Shambee, the victim's sister.
Tristan was the youngest of five children. His family says he was a strong swimmer.