The Valparaiso University student presumably drowned in the lake at Porter Beach over the weekend.
The student, identified as Rayan Sami Bokhari of Saudi Arabia, and eight college friends arrived at an area without lifeguards after being turned away from Indiana Dunes State Park because of high waves and rip currents.
Waves at the time reportedly reached 10 to 12 feet.
Authorities say Bokhari was found dead Monday at the Indiana Dunes National Lakeshore about a mile from where he was last swimming on Sunday.
Bokhari was a sophomore at Valparaiso University. More than 150 Valparaiso students and faculty members gathered at a prayer service for him. The Times of Munster reports mourners signed a remembrance book, lit candles and walked in a procession to the school's church for a silent vigil Monday night.
(The Associated Press contributed to this report. Information from: The Times.)