Commercial divers used inflatable airbags to lift the damaged vessel to the surface before towing it to 31st Street Harbor. A recovery operation is underway to remove a 42-foot boat that sank along Chicago's lakefront. Lake Michigan sunken boat recoveryThe boat went down after crashing into rocks near Morgan Point on Tuesday evening, according to TowBoatUS, the company leading the recovery. Once the boat was afloat, crews planned to tow it about two miles to 31st Street Harbor at about 4 to 5 mph. The backstory:TowBoatUS recently completed a similar recovery operation on July 8, when crews removed a 38-foot boat from Lake Michigan near 31st Street Harbor after a Fourth of July weekend boating accident.