Rescue crews are searching Lake Michigan after a 54-year-old boater fell from a sailboat Saturday evening more than a mile offshore.
Around 7:30 p.m., a Coast Guard search and rescue coordinator received a call from the owner of a sailboat named Three's Company reporting a man overboard in North Belmont Harbor.
A boat crew, air and Chicago marine units were sent to the scene.
Sailors on the boat told authorities they were in Lake Michigan between North Avenue Beach and the entrance to Diversey Harbor when Daniel Brown fell off the bow of the vessel after a railing broke. He was wearing khaki shorts and a gray T-shirt when he fell in, officials said.
Five other boaters on the vessel saw the man resurface once and lost sight of him while trying to toss him a life ring, according to a release from the Coast Guard.
A Chicago marine unit later towed the sailboat to Belmont Harbor.
Crews from the Police Marine Unit, Chicago Fire Department and U.S. Coast Guard searched overnight and into Sunday morning.
Coast Guard officials say they've covered more than 98 square miles in the nearly 24-hour search.
Police said Brown is a triathlete and a strong swimmer, who could have made it to shore.
They have since issued a missing person report, describing Brown as 5 feet, 11 inches tall, weighing 160 pounds with brown eyes, gray-brown hair with a tattoo of a heart on his left shoulder.
"There's two- to four-foot waves, the body could be lying in trough between the highs of the waves," said veteran boater Jimmy Hickey. "I don't think you can swim for more than five minutes even if he's a good swimmer. You get so cold so fast."
Officials moved their search south of Belmont Harbor Sunday afternoon because water currents were pushing south and toward the shoreline.
The Coast Guard suspended their search Sunday afternoon, but Chicago Police Marine Unit said they would continue to search the waters.