As Napoleon Solo sinks, Callahan is reluctant to release the line tied to the doomed vessel. Why?

If Callahan had been able to salvage Napoleon Solo's reserves of food and water, how might the story be different?

What are the qualities that allow Callahan to survive his ordeal? Are these common qualities?

Why does Callahan come to think of himself as his own crew? What does this say about his state of mind?

How much of Callahan's success or failure is due to simple dumb luck? Is here merely lucky/unlucky or does he create his own luck?

Suppose Callahan were confident that he would soon be rescued - how might that story have been different? What if he had no hope of rescue?

Callahan repeatedly talks about the idea of sailing alone versus sailing with a companion. What if he had been set...