Here's one of a bajillion whoop sections. Bright orange "Danger" signs were plentiful. Casey and crew did a superb job of marking the course. It was entirely possible to navigate the distance without the aid of GPS. More of Bob Bower's sage advice came to mind: "GPS is not radar. Let's say you travel 125 feet per second at 60 mph. If the GPS signal updates the display every two seconds, what you're seeing on the screen really happened 250 feet ago!"