What is the importance of Matt's compass in the novel, Airborn?

Given to Matt by his father on his tenth birthday, Matt's compass is inscribed with the words, "From one sailmaker to another", and he carries it with him always. It has a hinged lid and is made of brass and glass. When Matt had still been at home, he used to let it find north and then track his father based on where he was at the time. When he died three years earlier, Matt had stopped looking at it. His father couldn't be reached now.