Old friends Emma and Lani are invited on a boat tour in Thailand to visit a remote shark sanctuary bay. They hope to see the magnificent tiger sharks who have made the secluded spot their home. In the capable hands of their captain, Mandal and his boatman Ruhan, the young women are entranced by the beauty of this secret paradise. When a giant female shark gets tangled in the bait chain while ramming the motor in an attempt to escape, the two friends end up much closer to nature than they bargained for. Isolated and now fast sinking, with space for only one person on their life raft, the group must together call on all their resources to survive.