Half-safe

The book is the story of Ben Carlin's trip around the world in his self-made, dangerous land/water craft. He said he was safe only half the time, thus the title. I met Ben Carlin when I was a little girl; he came to visit my next-door neighbors, and he was driving the Half-Safe. It was the color of the yellow lines on a road, and had been constructed on the body of a Jeep. He had painted a map of his travels on its side. I have a photo of it.