The Cook County Medical Examiner's Office identified the woman whose body was recovered Monday morning as 53-year-old Cristen Bolan.
The office did not immediately provide any additional information about Bolan.
On Sunday, Bolan and another woman sailed from Evanston in a 12-foot sailboat, before it capsized at dusk.
Around 2 a.m. Monday, the other woman swam about 2 miles to the shore of Tower Road Beach, asking for help, according to Winnetka fire officials.
The woman told authorities Bolan was still missing.
The Winnetka Fire Department began a search-and-rescue mission shortly after the first woman was found.
After hours of searching, the Coast Guard found Bolan's body around 7 a.m., about a mile off shore, north of Winnetka. She was taken into Chicago's Montrose Harbor.
The sailboat was found about 2 to 3 miles off shore, according to the fire department.
This comes as crews have not yet found a man, who reportedly fell off a boat on Saturday afternoon near the enclosed boating area, also known as the "Playpen," close to downtown Chicago.
A teen boy also died Monday, after falling off a raft near Montrose Beach on Chicago's North Side.
Later Monday, a couple was rescued by a passerby after struggling to swim near Montrose Harbor.