Cole, a young fisherman in Blackrock Cove, Maine, is betrayed by his uncle Frank and left adrift at sea. He rescues the mermaid Mara at Devil’s Teeth Reef and receives a pearl that lets him command fish. With it, he returns with a boatload of bluefin, exposes Frank, rejects his materialistic ex, and defeats powerful snobs with blue lobsters, ambergris, and legendary white-gold ambergris. He even summons a sperm whale before the Aurora’s guests. When East Coast tycoon Arthur Blackwood proposes a Devil’s Teeth Reef wager, Cole sails his father’s rebuilt boat with loyal old crew, secretly guarded by Mara, rising from poor deckhand to a sea king.