Boat Smoke
Boat smoke is the exhaust gas that comes out of a 2 stroke motor that is common to many pontoon boats. This exhaust gas cloud typically has a bluish tint that typically emits as a motor is started up or fast acceleration takes place. A humid, hot day with minimal or no air movement will cause a boat smoke cloud to form over the water or in coves on the lake. “2 stroke smoke hangs around!”
Many educated people would mistake a cloud over water for fog but in reality it is just boat smoke.