Instead of going up the ladder, Dan, racked by guilt, decides to swim off and let himself drown. Earlier, he had been screaming "it should have been me". Amy later sees him drowning slowly, throws in a life ring and then jumps in to save him, all the while vividly recalling her childhood inability to save her father from drowning. The scene ends inconclusively with a shot of Amy's father lying dead on the seabed, followed by a whiteout.
The penultimate scene takes place at an unspecified time, on a clear calm day. A fishing boat approaches the yacht, seeing the lowered ladder and life ring still floating in the water - no one had pulled them in. The yacht appears empty except for the sound of baby Sarah crying on the lower deck.
In the final scene, on the upper deck, in slow motion, a quiet Amy stands looking around; she looks at Dan, who is lying facedown on the deck. While the ending caused some confusion among viewers, the film's director has indicated that five out of the six adults die, and Lauren just drifted to an unknown island.