What was the significance of the hatchet in the book Hatchet?

The main idea of the book hatchet is a young boy that is visiting his dad for the summer and takes a plane with only two seats, him and a pilot. Somehow as the pilot was flying the plane in an unknown area, he was stuck with a heart attack and could no longer live. The plane crashed, but the boy survived and the whole story is just how he survived in the wild by himself. Which towards