Phillip is an 11-year-old American boy living in Curaçao during World War II. Initially naive about the dangers of the war, he views the conflict as an exciting adventure. Raised with his mother's prejudiced views, he initially holds racist assumptions about Black people, which color his interactions when he becomes stranded at sea.

Timothy is an elderly Black man, roughly 70 years old, from Charlotte Amalie in St. Thomas. Having worked on ships and fishing boats since he was a young boy, he possesses a deep, practical knowledge of the Caribbean Sea and survival tactics. He assumes the role of protector and mentor to Phillip, demonstrating patience and resilience despite the boy's initial hostility.

Grace is Phillip's mother, a woman originally from Virginia who is deeply unhappy living in Curaçao. She is highly protective of her son and terrified of the wartime violence creeping closer to their home. Openly prejudiced, she avoids contact with the Black residents of Curaçao and insists on fleeing the island by ship to escape the conflict.

Phillip Sr. is an American who moved his family to Curaçao to help the Allied war effort by producing aircraft fuel. He is a pragmatic, dedicated, and patriotic worker who answers his son's questions about the conflict honestly. He believes his family is reasonably safe on the island and disagrees with his wife's insistence on leaving.

Henrik is an 11-year-old Dutch boy and Phillip's close friend in Curaçao. Because his father works for the local government, Henrik often has more accurate information about the war than Phillip does. Unlike Phillip, Henrik takes the conflict seriously, largely because his home country of the Netherlands has been conquered by the Nazis.

Stew Cat is a feline companion who survives the torpedo attack on the SS Hato and ends up on the life raft with Timothy and Phillip. He serves as a quiet presence during the ordeal, acting as a source of physical comfort for Phillip and a source of superstitious anxiety for Timothy.