How does the story suggest that …

Optimism is a determination to overcome difficulties. It raises one’s spirits and helps one overcome stress and difficulty with ease. The story displays courage and optimism shown by everyone at the time of a difficult situation. Survival happens only because of the optimistic struggle that the family carries on with the inclination to look at the bright side in the situation.
The level of perseverance in the author rises when Jonathan says, “We’re not afraid of dying if we can all be together. Besides, the caricatures of him and Mary, drawn by Sue, helps his determination and optimism to grow many folds. The positive outlook of the children infuses positivity in the narrator. He rigorously calculates their position and finally asks Larry to steer a course of 185 degrees. Though he lost all hopes by then, he does not show it and optimistically told Larry that they would spot the island by about 5 p.m. Fortunately, their struggle and optimism pays off and they manage to find Ile Amsterdam by the evening.