Okay, so the Sweet Judy is a boat—but if they're going to personify her so much, we're going to treat her like a character. They call ships "her" for a reason.
In this case, the Sweet Judy is like a mother. She's not a very good mother (after all, she leaves Daphne stranded on a deserted island), but she provides for her children, i.e., Mau and his people. She provides for them as they "pecked away at the boat like grandfather birds at a carcass" (6.93). So, okay, maybe she'd only be like a mother if her children were cannibals but, contrary to what Daphne's grandmother believes, Mau and his people are not.
Still the Judy has "a good soul [...] It was a shame to break her up" (9.176). People have souls. (Right, Mau? Ataba? Anyone? Bueller?) Her decay brings life, just like in that one movie about the lions.
In the end, after selling the golden door to the cave of the gods, Mau and his people make a new door, one using the figurehead from the Sweet Judy, because "If any nonliving thing had earned respect, it had been the Judy" (15.317). And what better representation of gods than a figurehead?