In Jun Do's quest to assemble a family, he inadvertently picks up the Second Mate, who comes to silently adore him. While everyone can see his influence on the younger man (the Captain tells Jun Do to keep his crazy to himself so that it doesn't rub off on the Second Mate), it's not until he's defected and Jun Do spends time with the Second Mate's wife that he truly understands the extent of the Second Mate's affection:
"All I know about you is that my husband, who had the maturity of a thirteen-year-old, worshiped you. That's why he fiddled with your radios. That's why he nearly burned the ship up reading your dictionaries by candlelight in the toilet." (101)
Despite his lack of maturity and his sidekick persona, the Second Mate has a level of imagination unrivaled by his "older brother." In fact, it's this ability to imagine a better life that causes a rift between Jun Do and the Second Mate and prompts the Second Mate's escape from the boat. When they figure out that the ghost transmissions are not coming from under the sea or from a league of nations conspiring against North Korea, the Second Mate has a meltdown:
"They're in space together," he said. "They're supposed to be our enemies, but they're up their laughing and screwing around." He lowered the directional and looked at Jun Do. "You were wrong," he said. "You were wrong—they are doing it for peace and f***ing brotherhood." (79)
Now, it's clear that the Second Mate's break with his society is not entirely due to Jun Do's influence. Jun Do learns from the Second Mate's wife that he was always making crazy getaway plans, promising his beautiful wife to take her to a better place.
But in the end, the Second Mate doesn't care about loyalty. Despite his beautiful wife and the camaraderie of his mates, he does feel he has nothing to lose. He understands that life in a box is no life at all, and if his wife and the rest of the crew lose their lives over his defection attempt, so be it. As he floats away, he tells Jun Do: "We're the ones at the bottom of the ocean. You helped me see that" (80). We're pretty sure that Jun Do would like to opt out of that distinction.