(Clackamas, OR) -- A Clackamas County firefighter has passed a rigorous course to become a "Georgia Smoke Diver." Only half of the participants in the course are able to complete it and pass. Officials say 59-year-old Josh Tyler spent up to 12 hours a day for six days taking part in exhausting drills, including full immersion in water while wearing firefighter gear. It pushes firefighters to physical and mental limits.