Naturally, the sea features prominently in Hawaii. More specifically, ocean voyages are foregrounded as a symbol of a journey into the unknown, and are crucial to the theme of Cultural Crossroads. Frequently, the central characters get their first glimpse of life beyond the narrow constraints of their native culture on board a boat or ship. When the Polynesians leave Bora Bora behind, they climb into a canoe that can hold 60 people. This will become their portable world for a long stretch of time.

Similarly, the missionaries who leave New England aboard the Thetis have no notion of the world they are about to enter. On the ship, Abner tries to hold Sunday services. This is highly impractical in rough weather, but he is quite put out that the crew would fail to observe the Sabbath as if they were pious churchgoers in a Massachusetts village. The Kees also experience a harrowing journey aboard the Carthaginian, but their troubles are multiplied because almost no one can speak their language, and the captain is afraid of a mutiny from his passengers. In each instance, the journey itself represents a cultural crossroads long before the frightened passengers ever make landfall.