Willie hates roller coasters.   He is an engineer.  When he looks at an amusement park ride, he sees the potential for human error, miscalculations, and structural weaknesses.  He can tie himself to the end of a climbing rope and throw himself off a bridge, but he HATES roller coasters. As long as he is the one tying the rope, building the ride or generally in control, he is fine. The fact that he let someone sit at the helm of a jet boat, driving 40 – 50 MPH down a shallow river, through a narrow canyon, coming centimeters from the canyon walls, took a lot of courage.  He also needed to overcome his PTSD caused by a brother that would drive their motorboat recklessly around lake Tahoe seeing how close they could come to a boat or dock at high speeds without hitting them.  Although completely gripped at the idea, he let go of his fears (mostly not to look too cowardly in front of his 12 year old daughter who after the ride, casually exited the boat and asked to go bungee jumping because the boat ride wasn’t scary enough), and purchased 4 tickets for the Shotover Jet Ride.

http://www.youtube.com/watch?v=Y9evp6MWZ_w&feature=youtu.be