CHICAGO (CBS) — A boater was plucked from Lake Michigan by rescue crews on Friday and is luck to be alive, officials said.

Two people were on a 20-foot boat about 10 to 12 miles offshore, when one of the men was knocked over by a wave and went into the water.

The second person on the vessel, did not know how to sail, but tried to throw the man a lifeline. The boat drifted and he lost sight of him in the water and called 911. Officials said the man was lucky that there was a cell signal in that part of the lake.

The Chicago Fire Department, Police Department and Coast Guard all responded from Calumet Harbor and rescued the man around 11:20 a.m.

Authorities used a heat-seeking sensor from a helicopter to pinpoint the boater’s location.

The man, who was not wearing a life vest, had been treading water for at least 20 minutes in 70 degree water.

The man was transported by CFD boat to 31st street.

The man was alert and waving as he was brought on shore on a stretcher.

The boat was recovered and brought to land, along with the second man.